v6_HEAD-0001-Fix-duplicate-insert-during-pg_createsubscri.patch
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Filename: v6_HEAD-0001-Fix-duplicate-insert-during-pg_createsubscri.patch
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Format: format-patch
Series: patch v6-0001
Subject: Fix duplicate insert during pg_createsubscriber
| File | + | − |
|---|---|---|
| src/bin/pg_basebackup/pg_createsubscriber.c | 6 | 1 |
From 8e2012e27748bab1d461949d2e331116c16e5503 Mon Sep 17 00:00:00 2001 From: Shlok Kyal <shlok.kyal.oss@gmail.com> Date: Mon, 28 Apr 2025 11:18:01 +0530 Subject: [PATCH v6_HEAD] Fix duplicate insert during pg_createsubscriber When pg_createsubscriber is run, the standby node is recovered to a point 'consistent_lsn' and promoted. Then, when the subscription is created, the replication origin is advanced to the 'consistent_lsn'. Then the subscription is enabled and the apply worker starts to send changes from 'consistent_lsn'. When this 'consistent_lsn' is an LSN corresponding to a COMMIT, the records for the transaction for that COMMIT are already replicated to the standby node during the recovery phase. Now, when the subscription is created, the replication origin is advanced and the subscription is enabled. The apply worker starts to apply changes from 'consistent_lsn'. So, records corresponding to the transaction whose COMMIT LSN is 'consistent_lsn' are replicated again. To avoid this, set recovery_target_inclusive = false instead of true. So the standby will recovery till point just before 'consistent_lsn'. And apply worker will start(after enabling of subscription) to apply changes from 'consistent_lsn'. So, above scenorio is avoided. --- src/bin/pg_basebackup/pg_createsubscriber.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/bin/pg_basebackup/pg_createsubscriber.c b/src/bin/pg_basebackup/pg_createsubscriber.c index 025b893a41e..9a656c49c69 100644 --- a/src/bin/pg_basebackup/pg_createsubscriber.c +++ b/src/bin/pg_basebackup/pg_createsubscriber.c @@ -1250,8 +1250,13 @@ setup_recovery(const struct LogicalRepInfo *dbinfo, const char *datadir, const c appendPQExpBufferStr(recoveryconfcontents, "recovery_target = ''\n"); appendPQExpBufferStr(recoveryconfcontents, "recovery_target_timeline = 'latest'\n"); + + /* + * Set recovery_target_inclusive = false to avoid reapplying the + * transaction committed at consistent_lsn after subscription is enabled. + */ appendPQExpBufferStr(recoveryconfcontents, - "recovery_target_inclusive = true\n"); + "recovery_target_inclusive = false\n"); appendPQExpBufferStr(recoveryconfcontents, "recovery_target_action = promote\n"); appendPQExpBufferStr(recoveryconfcontents, "recovery_target_name = ''\n"); -- 2.34.1