diff options
| author | Amit Kapila <akapila@postgresql.org> | 2025-07-24 09:05:32 +0000 |
|---|---|---|
| committer | Amit Kapila <akapila@postgresql.org> | 2025-07-24 09:05:32 +0000 |
| commit | e1c3654839e464957675344a1e949489d98b103b (patch) | |
| tree | 95d1d82d31a200c2a4d200e8f9a288ef297dda6a /src | |
| parent | 719dcf3c42260ceebfa2e8f6171a61161737a265 (diff) | |
Fix duplicate transaction replay during pg_createsubscriber.
Previously, the tool could replay the same transaction twice, once during
recovery, then again during replication after the subscriber was set up.
This occurred because the same recovery_target_lsn was used both to
finalize recovery and to start replication. If
recovery_target_inclusive = true, the transaction at that LSN would be
applied during recovery and then sent again by the publisher leading to
duplication.
To prevent this, we now set recovery_target_inclusive = false. This
ensures the transaction at recovery_target_lsn is not reapplied during
recovery, avoiding duplication when replication begins.
Bug #18897
Reported-by: Zane Duffield <duffieldzane@gmail.com>
Author: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 17, where it was introduced
Discussion: https://postgr.es/m/18897-d3db67535860dddb@postgresql.org
Diffstat (limited to 'src')
| -rw-r--r-- | src/bin/pg_basebackup/pg_createsubscriber.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/bin/pg_basebackup/pg_createsubscriber.c b/src/bin/pg_basebackup/pg_createsubscriber.c index 025b893a41e..3986882f042 100644 --- a/src/bin/pg_basebackup/pg_createsubscriber.c +++ b/src/bin/pg_basebackup/pg_createsubscriber.c @@ -1250,8 +1250,17 @@ 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 'lsn' after subscription is enabled. This is + * because the provided 'lsn' is also used as the replication start point + * for the subscription. So, the server can send the transaction committed + * at that 'lsn' after replication is started which can lead to applying + * the same transaction twice if we keep recovery_target_inclusive = true. + */ 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"); |