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 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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/utils/adt/pgstatfuncs.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/backend/utils/adt/pgstatfuncs.c') diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 6b3c464db83..e79b065d214 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1071,6 +1071,8 @@ PG_STAT_GET_DBENTRY_INT64(xact_commit) /* pg_stat_get_db_xact_rollback */ PG_STAT_GET_DBENTRY_INT64(xact_rollback) +/* pg_stat_get_db_conflict_logicalslot */ +PG_STAT_GET_DBENTRY_INT64(conflict_logicalslot) Datum pg_stat_get_db_stat_reset_time(PG_FUNCTION_ARGS) @@ -1104,6 +1106,7 @@ pg_stat_get_db_conflict_all(PG_FUNCTION_ARGS) result = (int64) (dbentry->conflict_tablespace + dbentry->conflict_lock + dbentry->conflict_snapshot + + dbentry->conflict_logicalslot + dbentry->conflict_bufferpin + dbentry->conflict_startup_deadlock); -- cgit v1.2.3