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pgsql: Fix race with timeline selection in logical decoding during prom 4+ messages / 1 participants [nested] [flat]
* pgsql: Fix race with timeline selection in logical decoding during prom @ 2026-06-11 08:30 Michael Paquier <michael@paquier.xyz> 0 siblings, 0 replies; 4+ messages in thread From: Michael Paquier @ 2026-06-11 08:30 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix race with timeline selection in logical decoding during promotion During promotion, there is a window where RecoveryInProgress() returns true but the WAL segments of the old timeline have already been removed. A logical decoding could pick up the old timeline in this window when reading a page, failing with the following error: ERROR: requested WAL segment ... has already been removed This issue does not lead to any data correctness issue, as retrying to decode the data works in follow-up decoding attempts. It impacts availability, though. Other WAL page read callbacks have a similar issue, this commit takes care of what should be the noisiest code path: logical decoding with START_REPLICATION in a WAL sender. A TAP test, based on an injection point waiting in the startup process after the segments have been removed/recycled, is added. This part is backpatched down to v17. This issue has been causing sporadic failures in the buildfarm, and was reproducible manually. This issue happens since logical decoding on standbys exists, down to v16. Reported-by: Alexander Lakhin <exclusion@gmail.com> Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com> Discussion: https://postgr.es/m/7daef094-abf3-4672-bc23-3df4763b16a3@gmail.com Backpatch-through: 16 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/eb4e7224a1c6f0058d708cdfda7326bbf884a871 Modified Files -------------- src/backend/access/transam/xlog.c | 2 + src/backend/replication/walsender.c | 24 +++++++- .../recovery/t/035_standby_logical_decoding.pl | 69 ++++++++++++++++++++++ 3 files changed, 94 insertions(+), 1 deletion(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
* pgsql: Fix race with timeline selection in logical decoding during prom @ 2026-06-11 08:30 Michael Paquier <michael@paquier.xyz> 0 siblings, 0 replies; 4+ messages in thread From: Michael Paquier @ 2026-06-11 08:30 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix race with timeline selection in logical decoding during promotion During promotion, there is a window where RecoveryInProgress() returns true but the WAL segments of the old timeline have already been removed. A logical decoding could pick up the old timeline in this window when reading a page, failing with the following error: ERROR: requested WAL segment ... has already been removed This issue does not lead to any data correctness issue, as retrying to decode the data works in follow-up decoding attempts. It impacts availability, though. Other WAL page read callbacks have a similar issue, this commit takes care of what should be the noisiest code path: logical decoding with START_REPLICATION in a WAL sender. A TAP test, based on an injection point waiting in the startup process after the segments have been removed/recycled, is added. This part is backpatched down to v17. This issue has been causing sporadic failures in the buildfarm, and was reproducible manually. This issue happens since logical decoding on standbys exists, down to v16. Reported-by: Alexander Lakhin <exclusion@gmail.com> Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com> Discussion: https://postgr.es/m/7daef094-abf3-4672-bc23-3df4763b16a3@gmail.com Backpatch-through: 16 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/b4bd1385043c4664a7b8894a811ba91a61c6e07f Modified Files -------------- src/backend/access/transam/xlog.c | 2 + src/backend/replication/walsender.c | 24 +++++++- .../recovery/t/035_standby_logical_decoding.pl | 69 ++++++++++++++++++++++ 3 files changed, 94 insertions(+), 1 deletion(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
* pgsql: Fix race with timeline selection in logical decoding during prom @ 2026-06-11 08:30 Michael Paquier <michael@paquier.xyz> 0 siblings, 0 replies; 4+ messages in thread From: Michael Paquier @ 2026-06-11 08:30 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix race with timeline selection in logical decoding during promotion During promotion, there is a window where RecoveryInProgress() returns true but the WAL segments of the old timeline have already been removed. A logical decoding could pick up the old timeline in this window when reading a page, failing with the following error: ERROR: requested WAL segment ... has already been removed This issue does not lead to any data correctness issue, as retrying to decode the data works in follow-up decoding attempts. It impacts availability, though. Other WAL page read callbacks have a similar issue, this commit takes care of what should be the noisiest code path: logical decoding with START_REPLICATION in a WAL sender. A TAP test, based on an injection point waiting in the startup process after the segments have been removed/recycled, is added. This part is backpatched down to v17. This issue has been causing sporadic failures in the buildfarm, and was reproducible manually. This issue happens since logical decoding on standbys exists, down to v16. Reported-by: Alexander Lakhin <exclusion@gmail.com> Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com> Discussion: https://postgr.es/m/7daef094-abf3-4672-bc23-3df4763b16a3@gmail.com Backpatch-through: 16 Branch ------ REL_17_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/16b89ff048391c7f1bb4758de203c82c1a6dd7b8 Modified Files -------------- src/backend/access/transam/xlog.c | 2 + src/backend/replication/walsender.c | 24 +++++++- .../recovery/t/035_standby_logical_decoding.pl | 69 ++++++++++++++++++++++ 3 files changed, 94 insertions(+), 1 deletion(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
* pgsql: Fix race with timeline selection in logical decoding during prom @ 2026-06-11 08:30 Michael Paquier <michael@paquier.xyz> 0 siblings, 0 replies; 4+ messages in thread From: Michael Paquier @ 2026-06-11 08:30 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix race with timeline selection in logical decoding during promotion During promotion, there is a window where RecoveryInProgress() returns true but the WAL segments of the old timeline have already been removed. A logical decoding could pick up the old timeline in this window when reading a page, failing with the following error: ERROR: requested WAL segment ... has already been removed This issue does not lead to any data correctness issue, as retrying to decode the data works in follow-up decoding attempts. It impacts availability, though. Other WAL page read callbacks have a similar issue, this commit takes care of what should be the noisiest code path: logical decoding with START_REPLICATION in a WAL sender. A TAP test, based on an injection point waiting in the startup process after the segments have been removed/recycled, is added. This part is backpatched down to v17. This issue has been causing sporadic failures in the buildfarm, and was reproducible manually. This issue happens since logical decoding on standbys exists, down to v16. Reported-by: Alexander Lakhin <exclusion@gmail.com> Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com> Discussion: https://postgr.es/m/7daef094-abf3-4672-bc23-3df4763b16a3@gmail.com Backpatch-through: 16 Branch ------ REL_16_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/8cd687c44b62cda3cc6dec88d414e8e2837dc56b Modified Files -------------- src/backend/replication/walsender.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2026-06-11 08:30 UTC | newest] Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-06-11 08:30 pgsql: Fix race with timeline selection in logical decoding during prom Michael Paquier <michael@paquier.xyz> 2026-06-11 08:30 pgsql: Fix race with timeline selection in logical decoding during prom Michael Paquier <michael@paquier.xyz> 2026-06-11 08:30 pgsql: Fix race with timeline selection in logical decoding during prom Michael Paquier <michael@paquier.xyz> 2026-06-11 08:30 pgsql: Fix race with timeline selection in logical decoding during prom Michael Paquier <michael@paquier.xyz>
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