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Logical replication woes
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* Logical replication woes
@ 2014-05-15 16:57  Heikki Linnakangas <hlinnakangas@vmware.com>
  0 siblings, 1 reply; 9+ messages in thread

From: Heikki Linnakangas @ 2014-05-15 16:57 UTC (permalink / raw)
  To: pgsql-hackers; Andres Freund <andres@2ndquadrant.com>

Spotted while testing pg_recvlogical:

1. Set up pg_recvlogical to receive:

./pg_recvlogical -S fooslot -d postgres --create
./pg_recvlogical -S fooslot -d postgres --start -f -

2. In another terminal, with psql:

create table foo (id int4);
begin;
  insert into foo values (4);
  alter table foo alter column id type text;
prepare transaction 'foo';
commit prepared 'foo';
insert into foo values (1);

3.  With current HEAD, after commit 
bb38fb0d43c8d7ff54072bfd8bd63154e536b384, this produces an assertion 
failure:

TRAP: FailedAssertion("!(((xid) != ((TransactionId) 0)))", File: 
"reorderbuffer.c", Line: 508)

I believe that's we no longer assign another XID to the transaction that 
does the COMMIT PREPARED. Previously, an extra XID, in addition to the 
XID of the prepared transaction, was assigned for use in locking the 
global transaction entry in shared memory, but that's no longer required.

However, even with that patch reverted, it doesn't work correctly:

ERROR:  could not map filenode "base/12142/16390" to relation OID
LOG:  starting logical decoding for slot fooslot
DETAIL:  streaming transactions committing after 0/16D1670, reading WAL 
from 0/16BC470

- Heikki


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^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 17:07  Heikki Linnakangas <hlinnakangas@vmware.com>
  parent: Heikki Linnakangas <hlinnakangas@vmware.com>
  0 siblings, 2 replies; 9+ messages in thread

From: Heikki Linnakangas @ 2014-05-15 17:07 UTC (permalink / raw)
  To: pgsql-hackers; Andres Freund <andres@2ndquadrant.com>

On 05/15/2014 07:57 PM, Heikki Linnakangas wrote:
> Spotted while testing pg_recvlogical:
>
> 1. Set up pg_recvlogical to receive:
>
> ./pg_recvlogical -S fooslot -d postgres --create
> ./pg_recvlogical -S fooslot -d postgres --start -f -
>
> 2. In another terminal, with psql:
>
> create table foo (id int4);
> begin;
>    insert into foo values (4);
>    alter table foo alter column id type text;
> prepare transaction 'foo';
> commit prepared 'foo';
> insert into foo values (1);
>
> 3.  With current HEAD, after commit
> bb38fb0d43c8d7ff54072bfd8bd63154e536b384, this produces an assertion
> failure:
>
> TRAP: FailedAssertion("!(((xid) != ((TransactionId) 0)))", File:
> "reorderbuffer.c", Line: 508)
>
> I believe that's we no longer assign another XID to the transaction that
> does the COMMIT PREPARED. Previously, an extra XID, in addition to the
> XID of the prepared transaction, was assigned for use in locking the
> global transaction entry in shared memory, but that's no longer required.
>
> However, even with that patch reverted, it doesn't work correctly:
>
> ERROR:  could not map filenode "base/12142/16390" to relation OID
> LOG:  starting logical decoding for slot fooslot
> DETAIL:  streaming transactions committing after 0/16D1670, reading WAL
> from 0/16BC470

Ok, so the immediate cause was quick to find: when decoding a 
commit-prepared WAL record, we have to use the XID from the record 
content (patch attached). The XID in the record header is the XID of the 
transaction doing the COMMIT PREPARED, which is always 0 after patch 
bb38fb0d43c8d7ff54072bfd8bd63154e536b384 which causes the assertion. But 
it was always wrong. After fixing, it no longer asserts or gives the 
above "could not map filenode" error.

However, it still doesn't seem right. When I do the above as a regular 
transaction, ie:

begin; insert into foo values (6);  alter table foo alter column id type 
text; commit;

pg_recvlogical prints this:

BEGIN 708
table public.foo: INSERT: id[text]:'6'
COMMIT 708

But if I do it as a prepared transaction:

begin; insert into foo values (7);  alter table foo alter column id type 
text; prepare transaction 'foo'; commit prepared 'foo';

pg_recvlogical prints nothing.

- Heikki

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Attachments:

fix-commit-prepared-decoding-1.patch (text/x-diff, 651B) download diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c index d6499d5..cc73652 100644 --- a/src/backend/replication/logical/decode.c +++ b/src/backend/replication/logical/decode.c @@ -225,7 +225,7 @@ DecodeXactOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf) subxacts = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]); invals = (SharedInvalidationMessage *) &(subxacts[xlrec->nsubxacts]); - DecodeCommit(ctx, buf, prec->xl_xid, xlrec->dbId, + DecodeCommit(ctx, buf, prec->xid, xlrec->dbId, xlrec->xact_time, xlrec->nsubxacts, subxacts, xlrec->nmsgs, invals);
^ permalink raw reply [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 17:11  Andres Freund <andres@2ndquadrant.com>
  parent: Heikki Linnakangas <hlinnakangas@vmware.com>
  1 sibling, 0 replies; 9+ messages in thread

From: Andres Freund @ 2014-05-15 17:11 UTC (permalink / raw)
  To: Heikki Linnakangas <hlinnakangas@vmware.com>; +Cc: pgsql-hackers

Hi,

On 2014-05-15 20:07:23 +0300, Heikki Linnakangas wrote:
> On 05/15/2014 07:57 PM, Heikki Linnakangas wrote:
> >Spotted while testing pg_recvlogical:
> >
> >1. Set up pg_recvlogical to receive:
> >
> >./pg_recvlogical -S fooslot -d postgres --create
> >./pg_recvlogical -S fooslot -d postgres --start -f -
> >
> >2. In another terminal, with psql:
> >
> >create table foo (id int4);
> >begin;
> >   insert into foo values (4);
> >   alter table foo alter column id type text;
> >prepare transaction 'foo';
> >commit prepared 'foo';
> >insert into foo values (1);
> >
> >3.  With current HEAD, after commit
> >bb38fb0d43c8d7ff54072bfd8bd63154e536b384, this produces an assertion
> >failure:
> >
> >TRAP: FailedAssertion("!(((xid) != ((TransactionId) 0)))", File:
> >"reorderbuffer.c", Line: 508)
> >
> >I believe that's we no longer assign another XID to the transaction that
> >does the COMMIT PREPARED. Previously, an extra XID, in addition to the
> >XID of the prepared transaction, was assigned for use in locking the
> >global transaction entry in shared memory, but that's no longer required.
> >
> >However, even with that patch reverted, it doesn't work correctly:
> >
> >ERROR:  could not map filenode "base/12142/16390" to relation OID
> >LOG:  starting logical decoding for slot fooslot
> >DETAIL:  streaming transactions committing after 0/16D1670, reading WAL
> >from 0/16BC470
> 
> Ok, so the immediate cause was quick to find: when decoding a
> commit-prepared WAL record, we have to use the XID from the record content
> (patch attached). The XID in the record header is the XID of the transaction
> doing the COMMIT PREPARED, which is always 0 after patch
> bb38fb0d43c8d7ff54072bfd8bd63154e536b384 which causes the assertion. But it
> was always wrong. After fixing, it no longer asserts or gives the above
> "could not map filenode" error.
> 
> However, it still doesn't seem right. When I do the above as a regular
> transaction, ie:
> 
> begin; insert into foo values (6);  alter table foo alter column id type
> text; commit;
> 
> pg_recvlogical prints this:
> 
> BEGIN 708
> table public.foo: INSERT: id[text]:'6'
> COMMIT 708
> 
> But if I do it as a prepared transaction:
> 
> begin; insert into foo values (7);  alter table foo alter column id type
> text; prepare transaction 'foo'; commit prepared 'foo';

Looking into it. I at some point dropped the prepared xact tests and
that was obviously a mistake. Will re-add them and fix.

Andres Freund

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^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 17:46  Andres Freund <andres@2ndquadrant.com>
  parent: Heikki Linnakangas <hlinnakangas@vmware.com>
  1 sibling, 2 replies; 9+ messages in thread

From: Andres Freund @ 2014-05-15 17:46 UTC (permalink / raw)
  To: Heikki Linnakangas <hlinnakangas@vmware.com>; +Cc: pgsql-hackers

On 2014-05-15 20:07:23 +0300, Heikki Linnakangas wrote:
> Ok, so the immediate cause was quick to find: when decoding a
> commit-prepared WAL record, we have to use the XID from the record content
> (patch attached). The XID in the record header is the XID of the transaction
> doing the COMMIT PREPARED, which is always 0 after patch
> bb38fb0d43c8d7ff54072bfd8bd63154e536b384 which causes the assertion. But it
> was always wrong. After fixing, it no longer asserts or gives the above
> "could not map filenode" error.
> 
> However, it still doesn't seem right. When I do the above as a regular
> transaction, ie:
> 
> begin; insert into foo values (6);  alter table foo alter column id type
> text; commit;
> 
> pg_recvlogical prints this:
> 
> BEGIN 708
> table public.foo: INSERT: id[text]:'6'
> COMMIT 708
> 
> But if I do it as a prepared transaction:
> 
> begin; insert into foo values (7);  alter table foo alter column id type
> text; prepare transaction 'foo'; commit prepared 'foo';

How very wierd. The reason for this is that
RecordTransactionCommitPrepared() forgets to fill a couple of fields in
xl_xact_commit. Any reason dbId/tsId aren't filled? They aren't strictly
needed because afaics they're only looked at for relcache invalidations
which prepared xacts don't support, but still?
That also explains why decoding for prepared xacts (besides the "typo"
you found) didn't work anymore - the filtering at commit was added
pretty late...

Attached patch fixes things, but I want to add some regression tests
before commit.

Greetings,

Andres Freund

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^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 17:49  Andres Freund <andres@2ndquadrant.com>
  parent: Andres Freund <andres@2ndquadrant.com>
  1 sibling, 0 replies; 9+ messages in thread

From: Andres Freund @ 2014-05-15 17:49 UTC (permalink / raw)
  To: Heikki Linnakangas <hlinnakangas@vmware.com>; +Cc: pgsql-hackers

On 2014-05-15 19:46:57 +0200, Andres Freund wrote:
> Attached patch fixes things, but I want to add some regression tests
> before commit.

And now actually attached. Will send a patch with regression tests later
tonight or tomorrow. Need to eat first...

Greetings,

Andres Freund

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Attachments:

prelim-decode-prepared-fix.patch (text/x-patch, 1.3K) download diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 2cefa08..5d8e195 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -2082,9 +2082,10 @@ RecordTransactionCommitPrepared(TransactionId xid, /* Emit the XLOG commit record */ xlrec.xid = xid; + xlrec.crec.dbId = MyDatabaseId; + xlrec.crec.tsId = MyDatabaseTableSpace; xlrec.crec.xact_time = GetCurrentTimestamp(); xlrec.crec.xinfo = initfileinval ? XACT_COMPLETION_UPDATE_RELCACHE_FILE : 0; - xlrec.crec.nmsgs = 0; xlrec.crec.nrels = nrels; xlrec.crec.nsubxacts = nchildren; xlrec.crec.nmsgs = ninvalmsgs; diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c index 06b99e7..603d083 100644 --- a/src/backend/replication/logical/decode.c +++ b/src/backend/replication/logical/decode.c @@ -225,7 +225,7 @@ DecodeXactOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf) subxacts = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]); invals = (SharedInvalidationMessage *) &(subxacts[xlrec->nsubxacts]); - DecodeCommit(ctx, buf, r->xl_xid, xlrec->dbId, + DecodeCommit(ctx, buf, prec->xid, xlrec->dbId, xlrec->xact_time, xlrec->nsubxacts, subxacts, xlrec->nmsgs, invals);
^ permalink raw reply [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 19:30  Heikki Linnakangas <hlinnakangas@vmware.com>
  parent: Andres Freund <andres@2ndquadrant.com>
  1 sibling, 2 replies; 9+ messages in thread

From: Heikki Linnakangas @ 2014-05-15 19:30 UTC (permalink / raw)
  To: Andres Freund <andres@2ndquadrant.com>; +Cc: pgsql-hackers

On 05/15/2014 08:46 PM, Andres Freund wrote:
> On 2014-05-15 20:07:23 +0300, Heikki Linnakangas wrote:
>> Ok, so the immediate cause was quick to find: when decoding a
>> commit-prepared WAL record, we have to use the XID from the record content
>> (patch attached). The XID in the record header is the XID of the transaction
>> doing the COMMIT PREPARED, which is always 0 after patch
>> bb38fb0d43c8d7ff54072bfd8bd63154e536b384 which causes the assertion. But it
>> was always wrong. After fixing, it no longer asserts or gives the above
>> "could not map filenode" error.
>>
>> However, it still doesn't seem right. When I do the above as a regular
>> transaction, ie:
>>
>> begin; insert into foo values (6);  alter table foo alter column id type
>> text; commit;
>>
>> pg_recvlogical prints this:
>>
>> BEGIN 708
>> table public.foo: INSERT: id[text]:'6'
>> COMMIT 708
>>
>> But if I do it as a prepared transaction:
>>
>> begin; insert into foo values (7);  alter table foo alter column id type
>> text; prepare transaction 'foo'; commit prepared 'foo';
>
> How very wierd. The reason for this is that
> RecordTransactionCommitPrepared() forgets to fill a couple of fields in
> xl_xact_commit. Any reason dbId/tsId aren't filled? They aren't strictly
> needed because afaics they're only looked at for relcache invalidations
> which prepared xacts don't support, but still?

Seems like an oversight in commit dd428c79, which added the fields to 
xl_xact_commit. They are needed. A prepared xact can indeed cause 
relcache invalidations, and removal of the init file. For example:

  begin; cluster pg_opclass using pg_opclass_oid_index ; prepare 
transaction 'foo'; commit prepared 'foo';

> Attached patch fixes things, but I want to add some regression tests
> before commit.

Looks good to me.

- Heikki


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^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 20:01  Andres Freund <andres@2ndquadrant.com>
  parent: Heikki Linnakangas <hlinnakangas@vmware.com>
  1 sibling, 0 replies; 9+ messages in thread

From: Andres Freund @ 2014-05-15 20:01 UTC (permalink / raw)
  To: Heikki Linnakangas <hlinnakangas@vmware.com>; +Cc: pgsql-hackers

On 2014-05-15 22:30:53 +0300, Heikki Linnakangas wrote:
> On 05/15/2014 08:46 PM, Andres Freund wrote:
> >On 2014-05-15 20:07:23 +0300, Heikki Linnakangas wrote:
> >How very wierd. The reason for this is that
> >RecordTransactionCommitPrepared() forgets to fill a couple of fields in
> >xl_xact_commit. Any reason dbId/tsId aren't filled? They aren't strictly
> >needed because afaics they're only looked at for relcache invalidations
> >which prepared xacts don't support, but still?
> 
> Seems like an oversight in commit dd428c79, which added the fields to
> xl_xact_commit. They are needed. A prepared xact can indeed cause relcache
> invalidations, and removal of the init file. For example:

Hm, so that part has to be backpatched to 9.0. Ick, I wonder if that's
been hit in production. Seems like it could cause pretty random looking
errors. It's easy enough to cause errors like:
ERROR:  could not open file "base/12753/12613": No such file or directory
I guess not many people will do relevant stuff in prepared xacts tho.

Greetings,

Andres Freund

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^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-15 20:58  Andres Freund <andres@2ndquadrant.com>
  parent: Heikki Linnakangas <hlinnakangas@vmware.com>
  1 sibling, 1 reply; 9+ messages in thread

From: Andres Freund @ 2014-05-15 20:58 UTC (permalink / raw)
  To: Heikki Linnakangas <hlinnakangas@vmware.com>; +Cc: pgsql-hackers

On 2014-05-15 22:30:53 +0300, Heikki Linnakangas wrote:
> >Attached patch fixes things, but I want to add some regression tests
> >before commit.
> 
> Looks good to me.

Attached are two patches. One for the unitialized dbId/tsId issue; one
for the decoding bug. The former should be backpatched.
Should you wonder about the slight reordering of the assignments in
RecordTransactionCommitPrepared() - I've made it more similar to RecordTransactionCommit()
to make it easier to see they are equivalent.

Thanks for the testing!

Greetings,

Andres Freund

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Attachments: download all (2 files, .tar.gz)

0001-Initialize-all-members-of-xl_xact_commit-during-prep.patch (text/x-patch, 1.8K) download From 07d0f4330f7c25bcec9e356527b0dc86372d2886 Mon Sep 17 00:00:00 2001 From: Andres Freund <andres@anarazel.de> Date: Thu, 15 May 2014 22:23:12 +0200 Subject: [PATCH 1/2] Initialize all members of xl_xact_commit during prepared transaction commits. Commit dd428c79 added dbId and tsId to the xl_xact_commit struct but missed that prepared transaction commits reuse that struct. Fix that. Because those fields were used WAL logged unitialized a hot standby node could miss relcache init file invalidations leading to errors like ERROR: could not open file "...": No such file or directory on the standby. A restart of the database is sufficient to fix the problem. As problems can only be triggered when a system table/index has been rewritten in a transaction using two phase commit the problem is unlikely to have affected many installations. Found while investigating a logical decoding bugreport from Heikki. Backpatch to 9.0 where the bug was introduced. --- src/backend/access/transam/twophase.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 2cefa08..d5409a6 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -2082,9 +2082,13 @@ RecordTransactionCommitPrepared(TransactionId xid, /* Emit the XLOG commit record */ xlrec.xid = xid; - xlrec.crec.xact_time = GetCurrentTimestamp(); + xlrec.crec.xinfo = initfileinval ? XACT_COMPLETION_UPDATE_RELCACHE_FILE : 0; - xlrec.crec.nmsgs = 0; + + xlrec.crec.dbId = MyDatabaseId; + xlrec.crec.tsId = MyDatabaseTableSpace; + + xlrec.crec.xact_time = GetCurrentTimestamp(); xlrec.crec.nrels = nrels; xlrec.crec.nsubxacts = nchildren; xlrec.crec.nmsgs = ninvalmsgs; -- 2.0.0.rc2.4.g1dc51c6.dirty
0002-Fix-typo-induced-bug-in-decoding-of-prepared-transac.patch (text/x-patch, 8.1K) download From de22d8e5308b1c4c509d8566317d9aea0956c2bc Mon Sep 17 00:00:00 2001 From: Andres Freund <andres@anarazel.de> Date: Thu, 15 May 2014 22:42:27 +0200 Subject: [PATCH 2/2] Fix typo-induced bug in decoding of prepared transactions. The decoding of prepared transaction commits accidentally used the xid of the transaction performing the COMMIT PREPARED. Before bb38fb0d43c8d that lead to those transactions not being decoded, afterwards to a assertion failure. Add tests for the decoding of prepared transactions. Bug found and fixed by Heikki Linnakangas; new regression test by Andres Freund. --- contrib/test_decoding/Makefile | 2 +- contrib/test_decoding/expected/ddl.out | 6 +-- contrib/test_decoding/expected/prepared.out | 82 +++++++++++++++++++++++++++++ contrib/test_decoding/sql/ddl.sql | 2 +- contrib/test_decoding/sql/prepared.sql | 50 ++++++++++++++++++ src/backend/replication/logical/decode.c | 2 +- 6 files changed, 138 insertions(+), 6 deletions(-) create mode 100644 contrib/test_decoding/expected/prepared.out create mode 100644 contrib/test_decoding/sql/prepared.sql diff --git a/contrib/test_decoding/Makefile b/contrib/test_decoding/Makefile index 685986c..58e0f38 100644 --- a/contrib/test_decoding/Makefile +++ b/contrib/test_decoding/Makefile @@ -37,7 +37,7 @@ submake-isolation: submake-test_decoding: $(MAKE) -C $(top_builddir)/contrib/test_decoding -REGRESSCHECKS=ddl rewrite toast permissions decoding_in_xact binary +REGRESSCHECKS=ddl rewrite toast permissions decoding_in_xact binary prepared regresscheck: all | submake-regress submake-test_decoding $(MKDIR_P) regression_output diff --git a/contrib/test_decoding/expected/ddl.out b/contrib/test_decoding/expected/ddl.out index 05a4bd3..37ff8b7 100644 --- a/contrib/test_decoding/expected/ddl.out +++ b/contrib/test_decoding/expected/ddl.out @@ -640,8 +640,8 @@ SELECT pg_drop_replication_slot('regression_slot'); (1 row) /* check that we aren't visible anymore now */ -SELECT * FROM pg_stat_replication; - pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | backend_xmin | state | sent_location | write_location | flush_location | replay_location | sync_priority | sync_state ------+----------+---------+------------------+-------------+-----------------+-------------+---------------+--------------+-------+---------------+----------------+----------------+-----------------+---------------+------------ +SELECT * FROM pg_replication_slots; + slot_name | plugin | slot_type | datoid | database | active | xmin | catalog_xmin | restart_lsn +-----------+--------+-----------+--------+----------+--------+------+--------------+------------- (0 rows) diff --git a/contrib/test_decoding/expected/prepared.out b/contrib/test_decoding/expected/prepared.out new file mode 100644 index 0000000..0f54f53 --- /dev/null +++ b/contrib/test_decoding/expected/prepared.out @@ -0,0 +1,82 @@ +-- predictability +SET synchronous_commit = on; +SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding'); + ?column? +---------- + init +(1 row) + +CREATE TABLE test_prepared1(id int); +CREATE TABLE test_prepared2(id int); +-- test simple successful use of a prepared xact +BEGIN; +INSERT INTO test_prepared1 VALUES (1); +PREPARE TRANSACTION 'test_prepared#1'; +COMMIT PREPARED 'test_prepared#1'; +INSERT INTO test_prepared1 VALUES (2); +-- test abort of a prepared xact +BEGIN; +INSERT INTO test_prepared1 VALUES (3); +PREPARE TRANSACTION 'test_prepared#2'; +ROLLBACK PREPARED 'test_prepared#2'; +INSERT INTO test_prepared1 VALUES (4); +-- test prepared xact ddl inside +BEGIN; +INSERT INTO test_prepared1 VALUES (5); +ALTER TABLE test_prepared1 ADD COLUMN data text; +INSERT INTO test_prepared1 VALUES (6, 'frakbar'); +PREPARE TRANSACTION 'test_prepared#3'; +-- test that we decode correctly while a uncommitted prepared xact +-- with ddl exist. +-- separate table because of the lock from the ALTER +-- this will come before the '5' row above as it commits before it. +INSERT INTO test_prepared2 VALUES (7); +COMMIT PREPARED 'test_prepared#3'; +-- make sure stuff still works +INSERT INTO test_prepared1 VALUES (8); +INSERT INTO test_prepared2 VALUES (9); +-- cleanup +DROP TABLE test_prepared1; +DROP TABLE test_prepared2; +-- show results +SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0'); + data +------------------------------------------------------------------------- + BEGIN + COMMIT + BEGIN + COMMIT + BEGIN + table public.test_prepared1: INSERT: id[integer]:1 + COMMIT + BEGIN + table public.test_prepared1: INSERT: id[integer]:2 + COMMIT + BEGIN + table public.test_prepared1: INSERT: id[integer]:4 + COMMIT + BEGIN + table public.test_prepared2: INSERT: id[integer]:7 + COMMIT + BEGIN + table public.test_prepared1: INSERT: id[integer]:5 + table public.test_prepared1: INSERT: id[integer]:6 data[text]:'frakbar' + COMMIT + BEGIN + table public.test_prepared1: INSERT: id[integer]:8 data[text]:null + COMMIT + BEGIN + table public.test_prepared2: INSERT: id[integer]:9 + COMMIT + BEGIN + COMMIT + BEGIN + COMMIT +(30 rows) + +SELECT pg_drop_replication_slot('regression_slot'); + pg_drop_replication_slot +-------------------------- + +(1 row) + diff --git a/contrib/test_decoding/sql/ddl.sql b/contrib/test_decoding/sql/ddl.sql index 555a59c..3811786 100644 --- a/contrib/test_decoding/sql/ddl.sql +++ b/contrib/test_decoding/sql/ddl.sql @@ -334,4 +334,4 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'inc SELECT pg_drop_replication_slot('regression_slot'); /* check that we aren't visible anymore now */ -SELECT * FROM pg_stat_replication; +SELECT * FROM pg_replication_slots; diff --git a/contrib/test_decoding/sql/prepared.sql b/contrib/test_decoding/sql/prepared.sql new file mode 100644 index 0000000..86fd030 --- /dev/null +++ b/contrib/test_decoding/sql/prepared.sql @@ -0,0 +1,50 @@ +-- predictability +SET synchronous_commit = on; +SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding'); + +CREATE TABLE test_prepared1(id int); +CREATE TABLE test_prepared2(id int); + +-- test simple successful use of a prepared xact +BEGIN; +INSERT INTO test_prepared1 VALUES (1); +PREPARE TRANSACTION 'test_prepared#1'; +COMMIT PREPARED 'test_prepared#1'; +INSERT INTO test_prepared1 VALUES (2); + +-- test abort of a prepared xact +BEGIN; +INSERT INTO test_prepared1 VALUES (3); +PREPARE TRANSACTION 'test_prepared#2'; +ROLLBACK PREPARED 'test_prepared#2'; + +INSERT INTO test_prepared1 VALUES (4); + +-- test prepared xact ddl inside +BEGIN; +INSERT INTO test_prepared1 VALUES (5); +ALTER TABLE test_prepared1 ADD COLUMN data text; +INSERT INTO test_prepared1 VALUES (6, 'frakbar'); +PREPARE TRANSACTION 'test_prepared#3'; + +-- test that we decode correctly while a uncommitted prepared xact +-- with ddl exist. + +-- separate table because of the lock from the ALTER +-- this will come before the '5' row above as it commits before it. +INSERT INTO test_prepared2 VALUES (7); + +COMMIT PREPARED 'test_prepared#3'; + +-- make sure stuff still works +INSERT INTO test_prepared1 VALUES (8); +INSERT INTO test_prepared2 VALUES (9); + +-- cleanup +DROP TABLE test_prepared1; +DROP TABLE test_prepared2; + +-- show results +SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0'); + +SELECT pg_drop_replication_slot('regression_slot'); diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c index 7b6114a..cc73652 100644 --- a/src/backend/replication/logical/decode.c +++ b/src/backend/replication/logical/decode.c @@ -225,7 +225,7 @@ DecodeXactOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf) subxacts = (TransactionId *) &(xlrec->xnodes[xlrec->nrels]); invals = (SharedInvalidationMessage *) &(subxacts[xlrec->nsubxacts]); - DecodeCommit(ctx, buf, r->xl_xid, xlrec->dbId, + DecodeCommit(ctx, buf, prec->xid, xlrec->dbId, xlrec->xact_time, xlrec->nsubxacts, subxacts, xlrec->nmsgs, invals); -- 2.0.0.rc2.4.g1dc51c6.dirty
^ permalink raw reply [nested|flat] 9+ messages in thread

* Re: Logical replication woes
@ 2014-05-16 08:35  Heikki Linnakangas <hlinnakangas@vmware.com>
  parent: Andres Freund <andres@2ndquadrant.com>
  0 siblings, 0 replies; 9+ messages in thread

From: Heikki Linnakangas @ 2014-05-16 08:35 UTC (permalink / raw)
  To: Andres Freund <andres@2ndquadrant.com>; +Cc: pgsql-hackers

On 05/15/2014 11:58 PM, Andres Freund wrote:
> On 2014-05-15 22:30:53 +0300, Heikki Linnakangas wrote:
>>> Attached patch fixes things, but I want to add some regression tests
>>> before commit.
>>
>> Looks good to me.
>
> Attached are two patches. One for the unitialized dbId/tsId issue; one
> for the decoding bug. The former should be backpatched.

Thanks, committed.

> Should you wonder about the slight reordering of the assignments in
> RecordTransactionCommitPrepared() - I've made it more similar to RecordTransactionCommit()
> to make it easier to see they are equivalent.

Makes sense.

- Heikki


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^ permalink  raw  reply  [nested|flat] 9+ messages in thread


end of thread, other threads:[~2014-05-16 08:35 UTC | newest]

Thread overview: 9+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2014-05-15 16:57 Logical replication woes Heikki Linnakangas <hlinnakangas@vmware.com>
2014-05-15 17:07 ` Heikki Linnakangas <hlinnakangas@vmware.com>
2014-05-15 17:11   ` Andres Freund <andres@2ndquadrant.com>
2014-05-15 17:46   ` Andres Freund <andres@2ndquadrant.com>
2014-05-15 17:49     ` Andres Freund <andres@2ndquadrant.com>
2014-05-15 19:30     ` Heikki Linnakangas <hlinnakangas@vmware.com>
2014-05-15 20:01       ` Andres Freund <andres@2ndquadrant.com>
2014-05-15 20:58       ` Andres Freund <andres@2ndquadrant.com>
2014-05-16 08:35         ` Heikki Linnakangas <hlinnakangas@vmware.com>

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