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[PATCH v8 6/7] Row pattern recognition patch (tests). 289+ messages / 2 participants [nested] [flat]
* [PATCH v8 6/7] Row pattern recognition patch (tests). @ 2023-09-25 05:01 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Tatsuo Ishii @ 2023-09-25 05:01 UTC (permalink / raw) --- src/test/regress/expected/rpr.out | 594 +++++++++++++++++++++++++++++ src/test/regress/parallel_schedule | 2 +- src/test/regress/sql/rpr.sql | 292 ++++++++++++++ 3 files changed, 887 insertions(+), 1 deletion(-) create mode 100644 src/test/regress/expected/rpr.out create mode 100644 src/test/regress/sql/rpr.sql diff --git a/src/test/regress/expected/rpr.out b/src/test/regress/expected/rpr.out new file mode 100644 index 0000000000..3e7ad943c9 --- /dev/null +++ b/src/test/regress/expected/rpr.out @@ -0,0 +1,594 @@ +-- +-- Test for row pattern definition clause +-- +CREATE TEMP TABLE stock ( + company TEXT, + tdate DATE, + price INTEGER +); +INSERT INTO stock VALUES ('company1', '2023-07-01', 100); +INSERT INTO stock VALUES ('company1', '2023-07-02', 200); +INSERT INTO stock VALUES ('company1', '2023-07-03', 150); +INSERT INTO stock VALUES ('company1', '2023-07-04', 140); +INSERT INTO stock VALUES ('company1', '2023-07-05', 150); +INSERT INTO stock VALUES ('company1', '2023-07-06', 90); +INSERT INTO stock VALUES ('company1', '2023-07-07', 110); +INSERT INTO stock VALUES ('company1', '2023-07-08', 130); +INSERT INTO stock VALUES ('company1', '2023-07-09', 120); +INSERT INTO stock VALUES ('company1', '2023-07-10', 130); +INSERT INTO stock VALUES ('company2', '2023-07-01', 50); +INSERT INTO stock VALUES ('company2', '2023-07-02', 2000); +INSERT INTO stock VALUES ('company2', '2023-07-03', 1500); +INSERT INTO stock VALUES ('company2', '2023-07-04', 1400); +INSERT INTO stock VALUES ('company2', '2023-07-05', 1500); +INSERT INTO stock VALUES ('company2', '2023-07-06', 60); +INSERT INTO stock VALUES ('company2', '2023-07-07', 1100); +INSERT INTO stock VALUES ('company2', '2023-07-08', 1300); +INSERT INTO stock VALUES ('company2', '2023-07-09', 1200); +INSERT INTO stock VALUES ('company2', '2023-07-10', 1300); +SELECT * FROM stock; + company | tdate | price +----------+------------+------- + company1 | 07-01-2023 | 100 + company1 | 07-02-2023 | 200 + company1 | 07-03-2023 | 150 + company1 | 07-04-2023 | 140 + company1 | 07-05-2023 | 150 + company1 | 07-06-2023 | 90 + company1 | 07-07-2023 | 110 + company1 | 07-08-2023 | 130 + company1 | 07-09-2023 | 120 + company1 | 07-10-2023 | 130 + company2 | 07-01-2023 | 50 + company2 | 07-02-2023 | 2000 + company2 | 07-03-2023 | 1500 + company2 | 07-04-2023 | 1400 + company2 | 07-05-2023 | 1500 + company2 | 07-06-2023 | 60 + company2 | 07-07-2023 | 1100 + company2 | 07-08-2023 | 1300 + company2 | 07-09-2023 | 1200 + company2 | 07-10-2023 | 1300 +(20 rows) + +-- basic test using PREV +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w, + nth_value(tdate, 2) OVER w AS nth_second + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + company | tdate | price | first_value | last_value | nth_second +----------+------------+-------+-------------+------------+------------ + company1 | 07-01-2023 | 100 | 100 | 140 | 07-02-2023 + company1 | 07-02-2023 | 200 | | | + company1 | 07-03-2023 | 150 | | | + company1 | 07-04-2023 | 140 | | | + company1 | 07-05-2023 | 150 | | | + company1 | 07-06-2023 | 90 | 90 | 120 | 07-07-2023 + company1 | 07-07-2023 | 110 | | | + company1 | 07-08-2023 | 130 | | | + company1 | 07-09-2023 | 120 | | | + company1 | 07-10-2023 | 130 | | | + company2 | 07-01-2023 | 50 | 50 | 1400 | 07-02-2023 + company2 | 07-02-2023 | 2000 | | | + company2 | 07-03-2023 | 1500 | | | + company2 | 07-04-2023 | 1400 | | | + company2 | 07-05-2023 | 1500 | | | + company2 | 07-06-2023 | 60 | 60 | 1200 | 07-07-2023 + company2 | 07-07-2023 | 1100 | | | + company2 | 07-08-2023 | 1300 | | | + company2 | 07-09-2023 | 1200 | | | + company2 | 07-10-2023 | 1300 | | | +(20 rows) + +-- last_value() should remain consistent +SELECT company, tdate, price, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + company | tdate | price | last_value +----------+------------+-------+------------ + company1 | 07-01-2023 | 100 | 140 + company1 | 07-02-2023 | 200 | + company1 | 07-03-2023 | 150 | + company1 | 07-04-2023 | 140 | + company1 | 07-05-2023 | 150 | + company1 | 07-06-2023 | 90 | 120 + company1 | 07-07-2023 | 110 | + company1 | 07-08-2023 | 130 | + company1 | 07-09-2023 | 120 | + company1 | 07-10-2023 | 130 | + company2 | 07-01-2023 | 50 | 1400 + company2 | 07-02-2023 | 2000 | + company2 | 07-03-2023 | 1500 | + company2 | 07-04-2023 | 1400 | + company2 | 07-05-2023 | 1500 | + company2 | 07-06-2023 | 60 | 1200 + company2 | 07-07-2023 | 1100 | + company2 | 07-08-2023 | 1300 | + company2 | 07-09-2023 | 1200 | + company2 | 07-10-2023 | 1300 | +(20 rows) + +-- omit "START" in DEFINE but it is ok because "START AS TRUE" is +-- implicitly defined. per spec. +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w, + nth_value(tdate, 2) OVER w AS nth_second + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + company | tdate | price | first_value | last_value | nth_second +----------+------------+-------+-------------+------------+------------ + company1 | 07-01-2023 | 100 | 100 | 140 | 07-02-2023 + company1 | 07-02-2023 | 200 | | | + company1 | 07-03-2023 | 150 | | | + company1 | 07-04-2023 | 140 | | | + company1 | 07-05-2023 | 150 | | | + company1 | 07-06-2023 | 90 | 90 | 120 | 07-07-2023 + company1 | 07-07-2023 | 110 | | | + company1 | 07-08-2023 | 130 | | | + company1 | 07-09-2023 | 120 | | | + company1 | 07-10-2023 | 130 | | | + company2 | 07-01-2023 | 50 | 50 | 1400 | 07-02-2023 + company2 | 07-02-2023 | 2000 | | | + company2 | 07-03-2023 | 1500 | | | + company2 | 07-04-2023 | 1400 | | | + company2 | 07-05-2023 | 1500 | | | + company2 | 07-06-2023 | 60 | 60 | 1200 | 07-07-2023 + company2 | 07-07-2023 | 1100 | | | + company2 | 07-08-2023 | 1300 | | | + company2 | 07-09-2023 | 1200 | | | + company2 | 07-10-2023 | 1300 | | | +(20 rows) + +-- the first row start with less than or equal to 100 +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | 100 | 140 + company1 | 07-02-2023 | 200 | | + company1 | 07-03-2023 | 150 | | + company1 | 07-04-2023 | 140 | | + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | 90 | 120 + company1 | 07-07-2023 | 110 | | + company1 | 07-08-2023 | 130 | | + company1 | 07-09-2023 | 120 | | + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | 50 | 1400 + company2 | 07-02-2023 | 2000 | | + company2 | 07-03-2023 | 1500 | | + company2 | 07-04-2023 | 1400 | | + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | 60 | 1200 + company2 | 07-07-2023 | 1100 | | + company2 | 07-08-2023 | 1300 | | + company2 | 07-09-2023 | 1200 | | + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- second row raises 120% +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price) * 1.2, + DOWN AS price < PREV(price) +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | 100 | 140 + company1 | 07-02-2023 | 200 | | + company1 | 07-03-2023 | 150 | | + company1 | 07-04-2023 | 140 | | + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | | + company1 | 07-07-2023 | 110 | | + company1 | 07-08-2023 | 130 | | + company1 | 07-09-2023 | 120 | | + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | 50 | 1400 + company2 | 07-02-2023 | 2000 | | + company2 | 07-03-2023 | 1500 | | + company2 | 07-04-2023 | 1400 | | + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | | + company2 | 07-07-2023 | 1100 | | + company2 | 07-08-2023 | 1300 | | + company2 | 07-09-2023 | 1200 | | + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- using NEXT +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UPDOWN) + DEFINE + START AS TRUE, + UPDOWN AS price > PREV(price) AND price > NEXT(price) +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | 100 | 200 + company1 | 07-02-2023 | 200 | | + company1 | 07-03-2023 | 150 | | + company1 | 07-04-2023 | 140 | 140 | 150 + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | | + company1 | 07-07-2023 | 110 | 110 | 130 + company1 | 07-08-2023 | 130 | | + company1 | 07-09-2023 | 120 | | + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | 50 | 2000 + company2 | 07-02-2023 | 2000 | | + company2 | 07-03-2023 | 1500 | | + company2 | 07-04-2023 | 1400 | 1400 | 1500 + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | | + company2 | 07-07-2023 | 1100 | 1100 | 1300 + company2 | 07-08-2023 | 1300 | | + company2 | 07-09-2023 | 1200 | | + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- using AFTER MATCH SKIP TO NEXT ROW +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP TO NEXT ROW + INITIAL + PATTERN (START UPDOWN) + DEFINE + START AS TRUE, + UPDOWN AS price > PREV(price) AND price > NEXT(price) +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | 100 | 200 + company1 | 07-02-2023 | 200 | | + company1 | 07-03-2023 | 150 | | + company1 | 07-04-2023 | 140 | 140 | 150 + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | | + company1 | 07-07-2023 | 110 | 110 | 130 + company1 | 07-08-2023 | 130 | | + company1 | 07-09-2023 | 120 | | + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | 50 | 2000 + company2 | 07-02-2023 | 2000 | | + company2 | 07-03-2023 | 1500 | | + company2 | 07-04-2023 | 1400 | 1400 | 1500 + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | | + company2 | 07-07-2023 | 1100 | 1100 | 1300 + company2 | 07-08-2023 | 1300 | | + company2 | 07-09-2023 | 1200 | | + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- match everything +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (A+) + DEFINE + A AS TRUE +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | 100 | 130 + company1 | 07-02-2023 | 200 | | + company1 | 07-03-2023 | 150 | | + company1 | 07-04-2023 | 140 | | + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | | + company1 | 07-07-2023 | 110 | | + company1 | 07-08-2023 | 130 | | + company1 | 07-09-2023 | 120 | | + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | 50 | 1300 + company2 | 07-02-2023 | 2000 | | + company2 | 07-03-2023 | 1500 | | + company2 | 07-04-2023 | 1400 | | + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | | + company2 | 07-07-2023 | 1100 | | + company2 | 07-08-2023 | 1300 | | + company2 | 07-09-2023 | 1200 | | + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- backtracking with reclassification of rows +-- using AFTER MATCH SKIP PAST LAST ROW +SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (A+ B+) + DEFINE + A AS price > 100, + B AS price > 100 +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | | + company1 | 07-02-2023 | 200 | 07-02-2023 | 07-05-2023 + company1 | 07-03-2023 | 150 | | + company1 | 07-04-2023 | 140 | | + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | | + company1 | 07-07-2023 | 110 | 07-07-2023 | 07-10-2023 + company1 | 07-08-2023 | 130 | | + company1 | 07-09-2023 | 120 | | + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | | + company2 | 07-02-2023 | 2000 | 07-02-2023 | 07-05-2023 + company2 | 07-03-2023 | 1500 | | + company2 | 07-04-2023 | 1400 | | + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | | + company2 | 07-07-2023 | 1100 | 07-07-2023 | 07-10-2023 + company2 | 07-08-2023 | 1300 | | + company2 | 07-09-2023 | 1200 | | + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- backtracking with reclassification of rows +-- using AFTER MATCH SKIP TO NEXT ROW +SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP TO NEXT ROW + INITIAL + PATTERN (A+ B+) + DEFINE + A AS price > 100, + B AS price > 100 +); + company | tdate | price | first_value | last_value +----------+------------+-------+-------------+------------ + company1 | 07-01-2023 | 100 | | + company1 | 07-02-2023 | 200 | 07-02-2023 | 07-05-2023 + company1 | 07-03-2023 | 150 | 07-03-2023 | 07-05-2023 + company1 | 07-04-2023 | 140 | 07-04-2023 | 07-05-2023 + company1 | 07-05-2023 | 150 | | + company1 | 07-06-2023 | 90 | | + company1 | 07-07-2023 | 110 | 07-07-2023 | 07-10-2023 + company1 | 07-08-2023 | 130 | 07-08-2023 | 07-10-2023 + company1 | 07-09-2023 | 120 | 07-09-2023 | 07-10-2023 + company1 | 07-10-2023 | 130 | | + company2 | 07-01-2023 | 50 | | + company2 | 07-02-2023 | 2000 | 07-02-2023 | 07-05-2023 + company2 | 07-03-2023 | 1500 | 07-03-2023 | 07-05-2023 + company2 | 07-04-2023 | 1400 | 07-04-2023 | 07-05-2023 + company2 | 07-05-2023 | 1500 | | + company2 | 07-06-2023 | 60 | | + company2 | 07-07-2023 | 1100 | 07-07-2023 | 07-10-2023 + company2 | 07-08-2023 | 1300 | 07-08-2023 | 07-10-2023 + company2 | 07-09-2023 | 1200 | 07-09-2023 | 07-10-2023 + company2 | 07-10-2023 | 1300 | | +(20 rows) + +-- +-- Aggregates +-- +-- using AFTER MATCH SKIP PAST LAST ROW +SELECT company, tdate, price, + first_value(price) OVER w, + last_value(price) OVER w, + max(price) OVER w, + min(price) OVER w, + sum(price) OVER w, + avg(price) OVER w, + count(price) OVER w +FROM stock +WINDOW w AS ( +PARTITION BY company +ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING +AFTER MATCH SKIP PAST LAST ROW +INITIAL +PATTERN (START UP+ DOWN+) +DEFINE +START AS TRUE, +UP AS price > PREV(price), +DOWN AS price < PREV(price) +); + company | tdate | price | first_value | last_value | max | min | sum | avg | count +----------+------------+-------+-------------+------------+------+-----+------+-----------------------+------- + company1 | 07-01-2023 | 100 | 100 | 140 | 200 | 100 | 590 | 147.5000000000000000 | 4 + company1 | 07-02-2023 | 200 | | | | | | | + company1 | 07-03-2023 | 150 | | | | | | | + company1 | 07-04-2023 | 140 | | | | | | | + company1 | 07-05-2023 | 150 | | | | | | | 0 + company1 | 07-06-2023 | 90 | 90 | 120 | 130 | 90 | 450 | 112.5000000000000000 | 4 + company1 | 07-07-2023 | 110 | | | | | | | + company1 | 07-08-2023 | 130 | | | | | | | + company1 | 07-09-2023 | 120 | | | | | | | + company1 | 07-10-2023 | 130 | | | | | | | 0 + company2 | 07-01-2023 | 50 | 50 | 1400 | 2000 | 50 | 4950 | 1237.5000000000000000 | 4 + company2 | 07-02-2023 | 2000 | | | | | | | + company2 | 07-03-2023 | 1500 | | | | | | | + company2 | 07-04-2023 | 1400 | | | | | | | + company2 | 07-05-2023 | 1500 | | | | | | | 0 + company2 | 07-06-2023 | 60 | 60 | 1200 | 1300 | 60 | 3660 | 915.0000000000000000 | 4 + company2 | 07-07-2023 | 1100 | | | | | | | + company2 | 07-08-2023 | 1300 | | | | | | | + company2 | 07-09-2023 | 1200 | | | | | | | + company2 | 07-10-2023 | 1300 | | | | | | | 0 +(20 rows) + +-- using AFTER MATCH SKIP TO NEXT ROW +SELECT company, tdate, price, + first_value(price) OVER w, + last_value(price) OVER w, + max(price) OVER w, + min(price) OVER w, + sum(price) OVER w, + avg(price) OVER w, + count(price) OVER w +FROM stock +WINDOW w AS ( +PARTITION BY company +ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING +AFTER MATCH SKIP TO NEXT ROW +INITIAL +PATTERN (START UP+ DOWN+) +DEFINE +START AS TRUE, +UP AS price > PREV(price), +DOWN AS price < PREV(price) +); + company | tdate | price | first_value | last_value | max | min | sum | avg | count +----------+------------+-------+-------------+------------+------+------+------+-----------------------+------- + company1 | 07-01-2023 | 100 | 100 | 140 | 200 | 100 | 590 | 147.5000000000000000 | 4 + company1 | 07-02-2023 | 200 | | | | | | | 0 + company1 | 07-03-2023 | 150 | | | | | | | 0 + company1 | 07-04-2023 | 140 | 140 | 90 | 150 | 90 | 380 | 126.6666666666666667 | 3 + company1 | 07-05-2023 | 150 | | | | | | | 0 + company1 | 07-06-2023 | 90 | 90 | 120 | 130 | 90 | 450 | 112.5000000000000000 | 4 + company1 | 07-07-2023 | 110 | 110 | 120 | 130 | 110 | 360 | 120.0000000000000000 | 3 + company1 | 07-08-2023 | 130 | | | | | | | 0 + company1 | 07-09-2023 | 120 | | | | | | | 0 + company1 | 07-10-2023 | 130 | | | | | | | 0 + company2 | 07-01-2023 | 50 | 50 | 1400 | 2000 | 50 | 4950 | 1237.5000000000000000 | 4 + company2 | 07-02-2023 | 2000 | | | | | | | 0 + company2 | 07-03-2023 | 1500 | | | | | | | 0 + company2 | 07-04-2023 | 1400 | 1400 | 60 | 1500 | 60 | 2960 | 986.6666666666666667 | 3 + company2 | 07-05-2023 | 1500 | | | | | | | 0 + company2 | 07-06-2023 | 60 | 60 | 1200 | 1300 | 60 | 3660 | 915.0000000000000000 | 4 + company2 | 07-07-2023 | 1100 | 1100 | 1200 | 1300 | 1100 | 3600 | 1200.0000000000000000 | 3 + company2 | 07-08-2023 | 1300 | | | | | | | 0 + company2 | 07-09-2023 | 1200 | | | | | | | 0 + company2 | 07-10-2023 | 1300 | | | | | | | 0 +(20 rows) + +-- +-- Error cases +-- +-- row pattern definition variable name must not appear more than once +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + ORDER BY tdate + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price), + UP AS price > PREV(price) +); +ERROR: syntax error at or near "ORDER" +LINE 6: ORDER BY tdate + ^ +-- pattern variable name must appear in DEFINE +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+ END) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +ERROR: syntax error at or near "END" +LINE 8: PATTERN (START UP+ DOWN+ END) + ^ +-- FRAME must start at current row when row patttern recognition is used +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +ERROR: FRAME must start at current row when row patttern recognition is used +-- SEEK is not supported +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP TO NEXT ROW + SEEK + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +ERROR: SEEK is not supported +LINE 8: SEEK + ^ +HINT: Use INITIAL. diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index 4df9d8503b..896531002b 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -98,7 +98,7 @@ test: publication subscription # Another group of parallel tests # select_views depends on create_view # ---------- -test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock indirect_toast equivclass +test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock indirect_toast equivclass rpr # ---------- # Another group of parallel tests (JSON related) diff --git a/src/test/regress/sql/rpr.sql b/src/test/regress/sql/rpr.sql new file mode 100644 index 0000000000..846e1af2d7 --- /dev/null +++ b/src/test/regress/sql/rpr.sql @@ -0,0 +1,292 @@ +-- +-- Test for row pattern definition clause +-- + +CREATE TEMP TABLE stock ( + company TEXT, + tdate DATE, + price INTEGER +); +INSERT INTO stock VALUES ('company1', '2023-07-01', 100); +INSERT INTO stock VALUES ('company1', '2023-07-02', 200); +INSERT INTO stock VALUES ('company1', '2023-07-03', 150); +INSERT INTO stock VALUES ('company1', '2023-07-04', 140); +INSERT INTO stock VALUES ('company1', '2023-07-05', 150); +INSERT INTO stock VALUES ('company1', '2023-07-06', 90); +INSERT INTO stock VALUES ('company1', '2023-07-07', 110); +INSERT INTO stock VALUES ('company1', '2023-07-08', 130); +INSERT INTO stock VALUES ('company1', '2023-07-09', 120); +INSERT INTO stock VALUES ('company1', '2023-07-10', 130); +INSERT INTO stock VALUES ('company2', '2023-07-01', 50); +INSERT INTO stock VALUES ('company2', '2023-07-02', 2000); +INSERT INTO stock VALUES ('company2', '2023-07-03', 1500); +INSERT INTO stock VALUES ('company2', '2023-07-04', 1400); +INSERT INTO stock VALUES ('company2', '2023-07-05', 1500); +INSERT INTO stock VALUES ('company2', '2023-07-06', 60); +INSERT INTO stock VALUES ('company2', '2023-07-07', 1100); +INSERT INTO stock VALUES ('company2', '2023-07-08', 1300); +INSERT INTO stock VALUES ('company2', '2023-07-09', 1200); +INSERT INTO stock VALUES ('company2', '2023-07-10', 1300); + +SELECT * FROM stock; + +-- basic test using PREV +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w, + nth_value(tdate, 2) OVER w AS nth_second + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + +-- last_value() should remain consistent +SELECT company, tdate, price, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + +-- omit "START" in DEFINE but it is ok because "START AS TRUE" is +-- implicitly defined. per spec. +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w, + nth_value(tdate, 2) OVER w AS nth_second + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + +-- the first row start with less than or equal to 100 +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + +-- second row raises 120% +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price) * 1.2, + DOWN AS price < PREV(price) +); + +-- using NEXT +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UPDOWN) + DEFINE + START AS TRUE, + UPDOWN AS price > PREV(price) AND price > NEXT(price) +); + +-- using AFTER MATCH SKIP TO NEXT ROW +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP TO NEXT ROW + INITIAL + PATTERN (START UPDOWN) + DEFINE + START AS TRUE, + UPDOWN AS price > PREV(price) AND price > NEXT(price) +); + +-- match everything + +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (A+) + DEFINE + A AS TRUE +); + +-- backtracking with reclassification of rows +-- using AFTER MATCH SKIP PAST LAST ROW +SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (A+ B+) + DEFINE + A AS price > 100, + B AS price > 100 +); + +-- backtracking with reclassification of rows +-- using AFTER MATCH SKIP TO NEXT ROW +SELECT company, tdate, price, first_value(tdate) OVER w, last_value(tdate) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP TO NEXT ROW + INITIAL + PATTERN (A+ B+) + DEFINE + A AS price > 100, + B AS price > 100 +); + +-- +-- Aggregates +-- + +-- using AFTER MATCH SKIP PAST LAST ROW +SELECT company, tdate, price, + first_value(price) OVER w, + last_value(price) OVER w, + max(price) OVER w, + min(price) OVER w, + sum(price) OVER w, + avg(price) OVER w, + count(price) OVER w +FROM stock +WINDOW w AS ( +PARTITION BY company +ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING +AFTER MATCH SKIP PAST LAST ROW +INITIAL +PATTERN (START UP+ DOWN+) +DEFINE +START AS TRUE, +UP AS price > PREV(price), +DOWN AS price < PREV(price) +); + +-- using AFTER MATCH SKIP TO NEXT ROW +SELECT company, tdate, price, + first_value(price) OVER w, + last_value(price) OVER w, + max(price) OVER w, + min(price) OVER w, + sum(price) OVER w, + avg(price) OVER w, + count(price) OVER w +FROM stock +WINDOW w AS ( +PARTITION BY company +ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING +AFTER MATCH SKIP TO NEXT ROW +INITIAL +PATTERN (START UP+ DOWN+) +DEFINE +START AS TRUE, +UP AS price > PREV(price), +DOWN AS price < PREV(price) +); + +-- +-- Error cases +-- + +-- row pattern definition variable name must not appear more than once +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + ORDER BY tdate + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price), + UP AS price > PREV(price) +); + +-- pattern variable name must appear in DEFINE +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+ END) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + +-- FRAME must start at current row when row patttern recognition is used +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING + INITIAL + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); + +-- SEEK is not supported +SELECT company, tdate, price, first_value(price) OVER w, last_value(price) OVER w + FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP TO NEXT ROW + SEEK + PATTERN (START UP+ DOWN+) + DEFINE + START AS TRUE, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); -- 2.25.1 ----Next_Part(Mon_Sep_25_14_26_30_2023_752)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v8-0007-Allow-to-print-raw-parse-tree.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 1441a051773..fe625d00f7d 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 42bfb9cd38f..32ee48eab51 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5d73c4dfbcf..780ca4b3ac0 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -525,6 +525,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --uN5gGi2rtCNSVbpC Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/backend/utils/activity/ 19.4% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index f8c4dada7c9..72c8aa7650b 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -24,6 +24,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "utils/lsyscache.h" +#include "utils/pgstat_internal.h" #include "utils/syscache.h" @@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + PendingBackendStats.pending_xid_count++; + backend_has_xactstats = true; + pgstat_report_fixed = true; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 47ce61e5093..5e509153656 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + PendingBackendStats.pending_xid_count = 0; backend_has_xactstats = false; } diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0fdbaf79780..d78633cae44 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending */ PgStat_Counter pending_xact_commit; PgStat_Counter pending_xact_rollback; + PgStat_Counter pending_xid_count; } PgStat_BackendPending; /* -- 2.34.1 --jg9kqX3osLGO+8A7 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend @ 2025-08-08 15:58 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 289+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. The counter is not part of PgStat_BackendPending, because we want to avoid an extra function call in this code path to increment the counter in PendingBackendStats. The counter increment here behaves more or less the same as we do for WAL statistics. --- src/backend/access/transam/varsup.c | 2 ++ src/backend/utils/activity/pgstat_backend.c | 6 +++++- src/include/pgstat.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) 10.1% src/backend/access/transam/ 69.3% src/backend/utils/activity/ 20.5% src/include/ diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index fe895787cb7..26c72cbe091 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "commands/dbcommands.h" #include "miscadmin.h" +#include "pgstat.h" #include "postmaster/autovacuum.h" #include "storage/pmsignal.h" #include "storage/proc.h" @@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact) /* LWLockRelease acts as barrier */ MyProc->xid = xid; ProcGlobal->xids[MyProc->pgxactoff] = xid; + XidGenCount++; } else { diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index bf164854c4b..8b530c510b9 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage; */ static bool backend_has_xactstats = false; +PgStat_Counter XidGenCount = 0; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref) shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit; shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback; + shbackendent->stats.xid_count += XidGenCount; PendingBackendStats.pending_xact_commit = 0; PendingBackendStats.pending_xact_rollback = 0; + XidGenCount = 0; backend_has_xactstats = false; } @@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags) has_pending_data = true; /* Some transaction data pending? */ - if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats) + if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0)) has_pending_data = true; if (!has_pending_data) diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9efc0e10ebf..94dd24b3eac 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,6 +492,7 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter xact_commit; PgStat_Counter xact_rollback; + PgStat_Counter xid_count; } PgStat_Backend; /* --------- @@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid, extern bool pgstat_tracks_backend_bktype(BackendType bktype); extern void pgstat_create_backend(ProcNumber procnum); +extern PGDLLIMPORT PgStat_Counter XidGenCount; + /* * Functions in pgstat_bgwriter.c */ -- 2.34.1 --u6+Li7FU79Mt/lVd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v3-0003-Adding-the-pg_stat_backend-view.patch" ^ permalink raw reply [nested|flat] 289+ messages in thread
end of thread, other threads:[~2025-08-08 15:58 UTC | newest] Thread overview: 289+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2023-09-25 05:01 [PATCH v8 6/7] Row pattern recognition patch (tests). Tatsuo Ishii <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]> 2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
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