From: Andres Freund Date: Sat, 8 Apr 2023 05:19:05 +0000 (-0700) Subject: Prevent use of invalidated logical slot in CreateDecodingContext() X-Git-Tag: REL_16_BETA1~256 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4397abd0a2af955326c0608d63f3716ce5901004;p=thirdparty%2Fpostgresql.git Prevent use of invalidated logical slot in CreateDecodingContext() Previously we had checks for this in multiple places. Support for logical decoding on standbys will add other forms of invalidation, making it worth while to centralize the checks. This slightly changes the error message for both the walsender and SQL interface. Particularly the SQL interface error was inaccurate, as the "This slot has never previously reserved WAL" portion was unreachable. Reviewed-by: "Drouvot, Bertrand" Reviewed-by: Melanie Plageman Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de --- diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c index c3ec97a0a62..6082d222d5d 100644 --- a/src/backend/replication/logical/logical.c +++ b/src/backend/replication/logical/logical.c @@ -518,6 +518,22 @@ CreateDecodingContext(XLogRecPtr start_lsn, errmsg("replication slot \"%s\" was not created in this database", NameStr(slot->data.name)))); + /* + * Check if slot has been invalidated due to max_slot_wal_keep_size. Avoid + * "cannot get changes" wording in this errmsg because that'd be + * confusingly ambiguous about no changes being available when called from + * pg_logical_slot_get_changes_guts(). + */ + if (MyReplicationSlot->data.invalidated == RS_INVAL_WAL_REMOVED) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("can no longer get changes from replication slot \"%s\"", + NameStr(MyReplicationSlot->data.name)), + errdetail("This slot has been invalidated because it exceeded the maximum reserved size."))); + + Assert(MyReplicationSlot->data.invalidated == RS_INVAL_NONE); + Assert(MyReplicationSlot->data.restart_lsn != InvalidXLogRecPtr); + if (start_lsn == InvalidXLogRecPtr) { /* continue from last position */ diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c index fa1b641a2b0..55a24c02c94 100644 --- a/src/backend/replication/logical/logicalfuncs.c +++ b/src/backend/replication/logical/logicalfuncs.c @@ -214,19 +214,6 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin LogicalOutputPrepareWrite, LogicalOutputWrite, NULL); - /* - * After the sanity checks in CreateDecodingContext, make sure the - * restart_lsn is valid. Avoid "cannot get changes" wording in this - * errmsg because that'd be confusingly ambiguous about no changes - * being available. - */ - if (XLogRecPtrIsInvalid(MyReplicationSlot->data.restart_lsn)) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), - errmsg("can no longer get changes from replication slot \"%s\"", - NameStr(*name)), - errdetail("This slot has never previously reserved WAL, or it has been invalidated."))); - MemoryContextSwitchTo(oldcontext); /* diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 75e8363e248..e40a9b1ba7b 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -1253,13 +1253,6 @@ StartLogicalReplication(StartReplicationCmd *cmd) ReplicationSlotAcquire(cmd->slotname, true); - if (XLogRecPtrIsInvalid(MyReplicationSlot->data.restart_lsn)) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), - errmsg("cannot read from logical replication slot \"%s\"", - cmd->slotname), - errdetail("This slot has been invalidated because it exceeded the maximum reserved size."))); - /* * Force a disconnect, so that the decoding code doesn't need to care * about an eventual switch from running in recovery, to running in a