From 26669757b6a7665c1069e77e6472bd8550193ca6 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Fri, 7 Apr 2023 23:11:28 -0700 Subject: Handle logical slot conflicts on standby During WAL replay on the standby, when a conflict with a logical slot is identified, invalidate such slots. There are two sources of conflicts: 1) Using the information added in 6af1793954e, logical slots are invalidated if required rows are removed 2) wal_level on the primary server is reduced to below logical Uses the infrastructure introduced in the prior commit. FIXME: add commit reference. Change InvalidatePossiblyObsoleteSlot() to use a recovery conflict to interrupt use of a slot, if called in the startup process. The new recovery conflict is added to pg_stat_database_conflicts, as confl_active_logicalslot. See 6af1793954e for an overall design of logical decoding on a standby. Bumps catversion for the addition of the pg_stat_database_conflicts column. Bumps PGSTAT_FILE_FORMAT_ID for the same reason. Author: "Drouvot, Bertrand" Author: Andres Freund Author: Amit Khandekar (in an older version) Reviewed-by: "Drouvot, Bertrand" Reviewed-by: Andres Freund Reviewed-by: Robert Haas Reviewed-by: Fabrízio de Royes Mello Reviewed-by: Bharath Rupireddy Reviewed-by: Amit Kapila Reviewed-by: Alvaro Herrera Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de --- src/backend/tcop/postgres.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'src/backend/tcop/postgres.c') diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index a10ecbaf50b..01b6cc1f7d3 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -2526,6 +2526,9 @@ errdetail_recovery_conflict(void) case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT: errdetail("User query might have needed to see row versions that must be removed."); break; + case PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT: + errdetail("User was using a logical slot that must be invalidated."); + break; case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK: errdetail("User transaction caused buffer deadlock with recovery."); break; @@ -3143,6 +3146,12 @@ RecoveryConflictInterrupt(ProcSignalReason reason) InterruptPending = true; break; + case PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT: + RecoveryConflictPending = true; + QueryCancelPending = true; + InterruptPending = true; + break; + default: elog(FATAL, "unrecognized conflict mode: %d", (int) reason); -- cgit v1.2.3