From 0135cc5c8921d2b3eeadc2575bb9e13ad018b39a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=81lvaro=20Herrera?= Date: Fri, 3 Apr 2026 21:01:23 +0200 Subject: [PATCH v51 10/10] CheckLogicalDecodingRequirements: be specific about which GUC is limiting --- src/backend/commands/repack_worker.c | 3 ++- src/backend/replication/logical/logical.c | 8 +++++--- src/backend/replication/logical/logicalfuncs.c | 2 +- src/backend/replication/slot.c | 18 ++++++++++++------ src/backend/replication/slotfuncs.c | 11 ++++++----- src/backend/replication/walsender.c | 5 +++-- src/include/replication/logical.h | 3 ++- src/include/replication/slot.h | 2 +- 8 files changed, 32 insertions(+), 20 deletions(-) diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c index 610592a05b0..ca827223845 100644 --- a/src/backend/commands/repack_worker.c +++ b/src/backend/commands/repack_worker.c @@ -224,7 +224,7 @@ repack_setup_logical_decoding(Oid relid) * Make sure we can use logical decoding. */ CheckSlotPermissions(); - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(true); /* * A single backend should not execute multiple REPACK commands at a time, @@ -252,6 +252,7 @@ repack_setup_logical_decoding(Oid relid) ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME, NIL, true, + true, InvalidXLogRecPtr, XL_ROUTINE(.page_read = read_local_xlog_page, .segment_open = wal_segment_open, diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c index f20a0fe70ad..a08aece5731 100644 --- a/src/backend/replication/logical/logical.c +++ b/src/backend/replication/logical/logical.c @@ -108,9 +108,9 @@ static void LoadOutputPlugin(OutputPluginCallbacks *callbacks, const char *plugi * decoding. */ void -CheckLogicalDecodingRequirements(void) +CheckLogicalDecodingRequirements(bool repack) { - CheckSlotRequirements(); + CheckSlotRequirements(repack); /* * NB: Adding a new requirement likely means that RestoreSlotFromDisk() @@ -305,6 +305,7 @@ StartupDecodingContext(List *output_plugin_options, * output_plugin_options -- contains options passed to the output plugin * need_full_snapshot -- if true, must obtain a snapshot able to read all * tables; if false, one that can read only catalogs is acceptable. + * for_repack -- if true, we're going to be decoding for REPACK. * restart_lsn -- if given as invalid, it's this routine's responsibility to * mark WAL as reserved by setting a convenient restart_lsn for the slot. * Otherwise, we set for decoding to start from the given LSN without @@ -325,6 +326,7 @@ LogicalDecodingContext * CreateInitDecodingContext(const char *plugin, List *output_plugin_options, bool need_full_snapshot, + bool for_repack, XLogRecPtr restart_lsn, XLogReaderRoutine *xl_routine, LogicalOutputPluginWriterPrepareWrite prepare_write, @@ -341,7 +343,7 @@ CreateInitDecodingContext(const char *plugin, * On a standby, this check is also required while creating the slot. * Check the comments in the function. */ - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(for_repack); /* shorter lines... */ slot = MyReplicationSlot; diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c index 9760818941d..512013b0ef0 100644 --- a/src/backend/replication/logical/logicalfuncs.c +++ b/src/backend/replication/logical/logicalfuncs.c @@ -115,7 +115,7 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin CheckSlotPermissions(); - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(false); if (PG_ARGISNULL(0)) ereport(ERROR, diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index 2c6c6773ad2..13004ed547a 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -1669,19 +1669,25 @@ CheckLogicalSlotExists(void) * slots. */ void -CheckSlotRequirements(void) +CheckSlotRequirements(bool repack) { + int limit; + /* * NB: Adding a new requirement likely means that RestoreSlotFromDisk() * needs the same check. */ - /* XXX we should be able to check exactly which type of slot we need */ - if (max_replication_slots + max_repack_replication_slots == 0) + if (repack) + limit = max_repack_replication_slots; + else + limit = max_replication_slots; + + if (limit == 0) ereport(ERROR, - (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), - errmsg("replication slots can only be used if \"%s\" > 0 or \"%s\" > 0", - "max_replication_slots", "max_repack_replication_slots"))); + errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("replication slots can only be used if \"%s\" > 0", + repack ? "max_repack_replication_slots" : "max_replication_slots")); if (wal_level < WAL_LEVEL_REPLICA) ereport(ERROR, diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c index 78dd3c4ea66..16fbd383735 100644 --- a/src/backend/replication/slotfuncs.c +++ b/src/backend/replication/slotfuncs.c @@ -90,7 +90,7 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS) CheckSlotPermissions(); - CheckSlotRequirements(); + CheckSlotRequirements(false); create_physical_replication_slot(NameStr(*name), immediately_reserve, @@ -164,6 +164,7 @@ create_logical_replication_slot(char *name, char *plugin, */ ctx = CreateInitDecodingContext(plugin, NIL, false, /* just catalogs is OK */ + false, /* not repack */ restart_lsn, XL_ROUTINE(.page_read = read_local_xlog_page, .segment_open = wal_segment_open, @@ -203,7 +204,7 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS) CheckSlotPermissions(); - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(false); create_logical_replication_slot(NameStr(*name), NameStr(*plugin), @@ -240,7 +241,7 @@ pg_drop_replication_slot(PG_FUNCTION_ARGS) CheckSlotPermissions(); - CheckSlotRequirements(); + CheckSlotRequirements(false); ReplicationSlotDrop(NameStr(*name), true); @@ -648,9 +649,9 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot) CheckSlotPermissions(); if (logical_slot) - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(false); else - CheckSlotRequirements(); + CheckSlotRequirements(false); LWLockAcquire(ReplicationSlotControlLock, LW_SHARED); diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 75ef3419a15..9d7d675fa96 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -1240,7 +1240,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd) Assert(cmd->kind == REPLICATION_KIND_LOGICAL); - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(false); /* * Initially create persistent slot as ephemeral - that allows us to @@ -1309,6 +1309,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd) Assert(IsLogicalDecodingEnabled()); ctx = CreateInitDecodingContext(cmd->plugin, NIL, need_full_snapshot, + false, InvalidXLogRecPtr, XL_ROUTINE(.page_read = logical_read_xlog_page, .segment_open = WalSndSegmentOpen, @@ -1466,7 +1467,7 @@ StartLogicalReplication(StartReplicationCmd *cmd) QueryCompletion qc; /* make sure that our requirements are still fulfilled */ - CheckLogicalDecodingRequirements(); + CheckLogicalDecodingRequirements(false); Assert(!MyReplicationSlot); diff --git a/src/include/replication/logical.h b/src/include/replication/logical.h index bc9d4ece672..bc075b16741 100644 --- a/src/include/replication/logical.h +++ b/src/include/replication/logical.h @@ -115,11 +115,12 @@ typedef struct LogicalDecodingContext } LogicalDecodingContext; -extern void CheckLogicalDecodingRequirements(void); +extern void CheckLogicalDecodingRequirements(bool repack); extern LogicalDecodingContext *CreateInitDecodingContext(const char *plugin, List *output_plugin_options, bool need_full_snapshot, + bool for_repack, XLogRecPtr restart_lsn, XLogReaderRoutine *xl_routine, LogicalOutputPluginWriterPrepareWrite prepare_write, diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h index c316a01a807..489af7d8d6c 100644 --- a/src/include/replication/slot.h +++ b/src/include/replication/slot.h @@ -378,7 +378,7 @@ extern void ReplicationSlotDropAtPubNode(WalReceiverConn *wrconn, char *slotname extern void StartupReplicationSlots(void); extern void CheckPointReplicationSlots(bool is_shutdown); -extern void CheckSlotRequirements(void); +extern void CheckSlotRequirements(bool repack); extern void CheckSlotPermissions(void); extern ReplicationSlotInvalidationCause GetSlotInvalidationCause(const char *cause_name); -- 2.47.3