From 648d6f55d4b1593d0f09ab3ee8dcc91d57bf4961 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy Date: Sat, 6 Apr 2024 06:22:28 +0000 Subject: [PATCH v37] Add inactive_timeout based replication slot invalidation. Till now, postgres has the ability to invalidate inactive replication slots based on the amount of WAL (set via max_slot_wal_keep_size GUC) that will be needed for the slots in case they become active. However, choosing a default value for max_slot_wal_keep_size is tricky. Because the amount of WAL a customer generates, and their allocated storage will vary greatly in production, making it difficult to pin down a one-size-fits-all value. It is often easy for developers to set a timeout of say 1 or 2 or 3 days at slot level, after which the inactive slots get invalidated. To achieve the above, postgres introduces a GUC allowing users set inactive timeout. The replication slots that are inactive for longer than specified amount of time get invalidated. The invalidation check happens at various locations to help being as latest as possible, these locations include the following: - Whenever the slot is acquired and the slot acquisition errors out if invalidated. - During checkpoint Note that this new invalidation mechanism won't kick-in for the slots that are currently being synced from the primary to the standby. Author: Bharath Rupireddy Reviewed-by: Bertrand Drouvot, Amit Kapila, Shveta Malik Discussion: https://www.postgresql.org/message-id/CALj2ACW4aUe-_uFQOjdWCEN-xXoLGhmvRFnL8SNw_TZ5nJe+aw@mail.gmail.com --- doc/src/sgml/config.sgml | 33 ++ doc/src/sgml/system-views.sgml | 7 + .../replication/logical/logicalfuncs.c | 2 +- src/backend/replication/logical/slotsync.c | 11 +- src/backend/replication/slot.c | 211 ++++++++++++- src/backend/replication/slotfuncs.c | 2 +- src/backend/replication/walsender.c | 4 +- src/backend/utils/adt/pg_upgrade_support.c | 2 +- src/backend/utils/misc/guc_tables.c | 12 + src/backend/utils/misc/postgresql.conf.sample | 1 + src/include/replication/slot.h | 8 +- src/test/recovery/meson.build | 1 + src/test/recovery/t/044_invalidate_slots.pl | 283 ++++++++++++++++++ 13 files changed, 553 insertions(+), 24 deletions(-) create mode 100644 src/test/recovery/t/044_invalidate_slots.pl diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 624518e0b0..42f7b15aa7 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -4547,6 +4547,39 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows + + replication_slot_inactive_timeout (integer) + + replication_slot_inactive_timeout configuration parameter + + + + + Invalidates replication slots that are inactive for longer than + specified amount of time. If this value is specified without units, + it is taken as seconds. A value of zero (which is default) disables + the timeout mechanism. This parameter can only be set in + the postgresql.conf file or on the server + command line. + + + + This invalidation check happens either when the slot is acquired + for use or during a checkpoint. The time since the slot has become + inactive is known from its + inactive_since value using which the + timeout is measured. + + + + Note that the inactive timeout invalidation mechanism is not + applicable for slots on the standby that are being synced from a + primary server (whose synced field is + true). + + + + track_commit_timestamp (boolean) diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml index 7ed617170f..063638beda 100644 --- a/doc/src/sgml/system-views.sgml +++ b/doc/src/sgml/system-views.sgml @@ -2580,6 +2580,13 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx perform logical decoding. It is set only for logical slots. + + + inactive_timeout means that the slot has been + inactive for the duration specified by + parameter. + + diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c index b4dd5cce75..56fc1a45a9 100644 --- a/src/backend/replication/logical/logicalfuncs.c +++ b/src/backend/replication/logical/logicalfuncs.c @@ -197,7 +197,7 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin else end_of_wal = GetXLogReplayRecPtr(NULL); - ReplicationSlotAcquire(NameStr(*name), true); + ReplicationSlotAcquire(NameStr(*name), true, true); PG_TRY(); { diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c index d18e2c7342..e92f559539 100644 --- a/src/backend/replication/logical/slotsync.c +++ b/src/backend/replication/logical/slotsync.c @@ -362,7 +362,7 @@ drop_local_obsolete_slots(List *remote_slot_list) if (synced_slot) { - ReplicationSlotAcquire(NameStr(local_slot->data.name), true); + ReplicationSlotAcquire(NameStr(local_slot->data.name), true, false); ReplicationSlotDropAcquired(); } @@ -575,6 +575,13 @@ synchronize_one_slot(RemoteSlot *remote_slot, Oid remote_dbid) " name slot \"%s\" already exists on the standby", remote_slot->name)); + /* + * Skip the sync if the local slot is already invalidated. We do this + * beforehand to avoid slot acquire and release. + */ + if (slot->data.invalidated != RS_INVAL_NONE) + return false; + /* * The slot has been synchronized before. * @@ -591,7 +598,7 @@ synchronize_one_slot(RemoteSlot *remote_slot, Oid remote_dbid) * pre-check to ensure that at least one of the slot properties is * changed before acquiring the slot. */ - ReplicationSlotAcquire(remote_slot->name, true); + ReplicationSlotAcquire(remote_slot->name, true, false); Assert(slot == MyReplicationSlot); diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index 3bddaae022..4a43b29d89 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -107,10 +107,11 @@ const char *const SlotInvalidationCauses[] = { [RS_INVAL_WAL_REMOVED] = "wal_removed", [RS_INVAL_HORIZON] = "rows_removed", [RS_INVAL_WAL_LEVEL] = "wal_level_insufficient", + [RS_INVAL_INACTIVE_TIMEOUT] = "inactive_timeout", }; /* Maximum number of invalidation causes */ -#define RS_INVAL_MAX_CAUSES RS_INVAL_WAL_LEVEL +#define RS_INVAL_MAX_CAUSES RS_INVAL_INACTIVE_TIMEOUT StaticAssertDecl(lengthof(SlotInvalidationCauses) == (RS_INVAL_MAX_CAUSES + 1), "array length mismatch"); @@ -140,6 +141,7 @@ ReplicationSlot *MyReplicationSlot = NULL; /* GUC variables */ int max_replication_slots = 10; /* the maximum number of replication * slots */ +int replication_slot_inactive_timeout = 0; /* * This GUC lists streaming replication standby server slot names that @@ -158,6 +160,7 @@ static XLogRecPtr ss_oldest_flush_lsn = InvalidXLogRecPtr; static void ReplicationSlotShmemExit(int code, Datum arg); static void ReplicationSlotDropPtr(ReplicationSlot *slot); +static bool InvalidatePossiblyInactiveSlot(ReplicationSlot *slot); /* internal persistency functions */ static void RestoreSlotFromDisk(const char *name); @@ -535,9 +538,14 @@ ReplicationSlotName(int index, Name name) * * An error is raised if nowait is true and the slot is currently in use. If * nowait is false, we sleep until the slot is released by the owning process. + * + * If check_for_timeout_invalidation is true, the slot is checked for + * invalidation based on replication_slot_inactive_timeout GUC, and an error is + * raised after making the slot ours. */ void -ReplicationSlotAcquire(const char *name, bool nowait) +ReplicationSlotAcquire(const char *name, bool nowait, + bool check_for_timeout_invalidation) { ReplicationSlot *s; int active_pid; @@ -615,6 +623,34 @@ retry: /* We made this slot active, so it's ours now. */ MyReplicationSlot = s; + /* + * Check if the given slot can be invalidated based on its inactive + * timeout. If yes, persist the invalidated state to disk and then error + * out. We do this only after making the slot ours to avoid anyone else + * acquiring it while we check for its invalidation. + */ + if (check_for_timeout_invalidation) + { + /* The slot is ours by now */ + Assert(s->active_pid == MyProcPid); + + if (InvalidateInactiveReplicationSlot(s, true)) + { + /* + * If the slot has been invalidated, recalculate the resource + * limits. + */ + ReplicationSlotsComputeRequiredXmin(false); + ReplicationSlotsComputeRequiredLSN(); + + 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 was inactive for more than replication_slot_inactive_timeout."))); + } + } + /* * The call to pgstat_acquire_replslot() protects against stats for a * different slot, from before a restart or such, being present during @@ -781,7 +817,7 @@ ReplicationSlotDrop(const char *name, bool nowait) { Assert(MyReplicationSlot == NULL); - ReplicationSlotAcquire(name, nowait); + ReplicationSlotAcquire(name, nowait, false); /* * Do not allow users to drop the slots which are currently being synced @@ -804,7 +840,7 @@ ReplicationSlotAlter(const char *name, bool failover) { Assert(MyReplicationSlot == NULL); - ReplicationSlotAcquire(name, false); + ReplicationSlotAcquire(name, false, true); if (SlotIsPhysical(MyReplicationSlot)) ereport(ERROR, @@ -980,6 +1016,20 @@ ReplicationSlotDropPtr(ReplicationSlot *slot) LWLockRelease(ReplicationSlotAllocationLock); } +/* + * Helper for ReplicationSlotSave + */ +static inline void +SaveGivenReplicationSlot(ReplicationSlot *slot, int elevel) +{ + char path[MAXPGPATH]; + + Assert(slot != NULL); + + sprintf(path, "pg_replslot/%s", NameStr(slot->data.name)); + SaveSlotToPath(slot, path, elevel); +} + /* * Serialize the currently acquired slot's state from memory to disk, thereby * guaranteeing the current state will survive a crash. @@ -987,12 +1037,21 @@ ReplicationSlotDropPtr(ReplicationSlot *slot) void ReplicationSlotSave(void) { - char path[MAXPGPATH]; + SaveGivenReplicationSlot(MyReplicationSlot, ERROR); +} - Assert(MyReplicationSlot != NULL); +/* + * Helper for ReplicationSlotMarkDirty + */ +static inline void +MarkGivenReplicationSlotDirty(ReplicationSlot *slot) +{ + Assert(slot != NULL); - sprintf(path, "pg_replslot/%s", NameStr(MyReplicationSlot->data.name)); - SaveSlotToPath(MyReplicationSlot, path, ERROR); + SpinLockAcquire(&slot->mutex); + slot->just_dirtied = true; + slot->dirty = true; + SpinLockRelease(&slot->mutex); } /* @@ -1005,14 +1064,7 @@ ReplicationSlotSave(void) void ReplicationSlotMarkDirty(void) { - ReplicationSlot *slot = MyReplicationSlot; - - Assert(MyReplicationSlot != NULL); - - SpinLockAcquire(&slot->mutex); - MyReplicationSlot->just_dirtied = true; - MyReplicationSlot->dirty = true; - SpinLockRelease(&slot->mutex); + MarkGivenReplicationSlotDirty(MyReplicationSlot); } /* @@ -1506,6 +1558,9 @@ ReportSlotInvalidation(ReplicationSlotInvalidationCause cause, case RS_INVAL_WAL_LEVEL: appendStringInfoString(&err_detail, _("Logical decoding on standby requires wal_level >= logical on the primary server.")); break; + case RS_INVAL_INACTIVE_TIMEOUT: + appendStringInfoString(&err_detail, _("The slot has been inactive for more than replication_slot_inactive_timeout.")); + break; case RS_INVAL_NONE: pg_unreachable(); } @@ -1550,6 +1605,12 @@ InvalidatePossiblyObsoleteSlot(ReplicationSlotInvalidationCause cause, XLogRecPtr initial_restart_lsn = InvalidXLogRecPtr; ReplicationSlotInvalidationCause invalidation_cause_prev PG_USED_FOR_ASSERTS_ONLY = RS_INVAL_NONE; + /* + * Use InvalidateInactiveReplicationSlot for inactive timeout based + * invalidation. + */ + Assert(cause != RS_INVAL_INACTIVE_TIMEOUT); + for (;;) { XLogRecPtr restart_lsn; @@ -1619,6 +1680,10 @@ InvalidatePossiblyObsoleteSlot(ReplicationSlotInvalidationCause cause, if (SlotIsLogical(s)) invalidation_cause = cause; break; + case RS_INVAL_INACTIVE_TIMEOUT: + /* not reachable */ + Assert(false); + break; case RS_INVAL_NONE: pg_unreachable(); } @@ -1787,6 +1852,12 @@ InvalidateObsoleteReplicationSlots(ReplicationSlotInvalidationCause cause, Assert(cause != RS_INVAL_WAL_REMOVED || oldestSegno > 0); Assert(cause != RS_INVAL_NONE); + /* + * Use InvalidateInactiveReplicationSlot for inactive timeout based + * invalidation. + */ + Assert(cause != RS_INVAL_INACTIVE_TIMEOUT); + if (max_replication_slots == 0) return invalidated; @@ -1823,6 +1894,97 @@ restart: return invalidated; } +/* + * Invalidate given slot based on replication_slot_inactive_timeout GUC. + * + * Returns true if the slot has got invalidated. + * + * Whether the given slot needs to be invalidated depends on the cause: + * - RS_INVAL_INACTIVE_TIMEOUT: inactive slot timeout occurs + * + * NB: This function also runs as part of checkpoint, so avoid raising errors + * if possible. + * + * Note that having a new function for inactive timeout invalidation mechanism + * instead of using InvalidateObsoleteReplicationSlots provides flexibility in + * calling it at slot-level opportunistically, and choosing whether or not to + * persist the slot info to disk. + */ +bool +InvalidateInactiveReplicationSlot(ReplicationSlot *slot, bool persist_state) +{ + if (!InvalidatePossiblyInactiveSlot(slot)) + return false; + + /* Make sure the invalidated state persists across server restart */ + MarkGivenReplicationSlotDirty(slot); + + if (persist_state) + SaveGivenReplicationSlot(slot, ERROR); + + ReportSlotInvalidation(RS_INVAL_INACTIVE_TIMEOUT, false, 0, + slot->data.name, InvalidXLogRecPtr, + InvalidXLogRecPtr, InvalidTransactionId); + + return true; +} + +/* + * Helper for InvalidateInactiveReplicationSlot + */ +static bool +InvalidatePossiblyInactiveSlot(ReplicationSlot *slot) +{ + ReplicationSlotInvalidationCause inavidation_cause = RS_INVAL_NONE; + + /* + * Quick exit if inactive timeout invalidation mechanism is disabled or + * the slot on standby is currently being synced from the primary. + * + * Note that we don't invalidate synced slots because, they are typically + * considered not active as they don't perform logical decoding to produce + * the changes. + */ + if (replication_slot_inactive_timeout == 0 || + (RecoveryInProgress() && slot->data.synced)) + return false; + + if (slot->inactive_since > 0) + { + TimestampTz now; + + LWLockAcquire(ReplicationSlotControlLock, LW_SHARED); + + /* + * We get the current time beforehand to avoid system call while + * holding the spinlock. + */ + now = GetCurrentTimestamp(); + + SpinLockAcquire(&slot->mutex); + + /* + * Check if the slot needs to be invalidated due to + * replication_slot_inactive_timeout GUC. We do this with the spinlock + * held to avoid race conditions -- for example the inactive_since + * could change, or the slot could be dropped. + */ + if (TimestampDifferenceExceeds(slot->inactive_since, now, + replication_slot_inactive_timeout * 1000)) + { + inavidation_cause = RS_INVAL_INACTIVE_TIMEOUT; + slot->data.invalidated = RS_INVAL_INACTIVE_TIMEOUT; + } + + SpinLockRelease(&slot->mutex); + LWLockRelease(ReplicationSlotControlLock); + + return (inavidation_cause == RS_INVAL_INACTIVE_TIMEOUT); + } + + return false; +} + /* * Flush all replication slots to disk. * @@ -1835,6 +1997,7 @@ void CheckPointReplicationSlots(bool is_shutdown) { int i; + bool invalidated = false; elog(DEBUG1, "performing replication slot checkpoint"); @@ -1858,6 +2021,13 @@ CheckPointReplicationSlots(bool is_shutdown) /* save the slot to disk, locking is handled in SaveSlotToPath() */ sprintf(path, "pg_replslot/%s", NameStr(s->data.name)); + /* + * Here's an opportunity to invalidate inactive replication slots + * based on timeout, so let's do it. + */ + if (InvalidateInactiveReplicationSlot(s, false)) + invalidated = true; + /* * Slot's data is not flushed each time the confirmed_flush LSN is * updated as that could lead to frequent writes. However, we decide @@ -1884,6 +2054,15 @@ CheckPointReplicationSlots(bool is_shutdown) SaveSlotToPath(s, path, LOG); } LWLockRelease(ReplicationSlotAllocationLock); + + /* + * If any slots have been invalidated, recalculate the resource limits. + */ + if (invalidated) + { + ReplicationSlotsComputeRequiredXmin(false); + ReplicationSlotsComputeRequiredLSN(); + } } /* diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c index dd6c1d5a7e..9ad3e55704 100644 --- a/src/backend/replication/slotfuncs.c +++ b/src/backend/replication/slotfuncs.c @@ -539,7 +539,7 @@ pg_replication_slot_advance(PG_FUNCTION_ARGS) moveto = Min(moveto, GetXLogReplayRecPtr(NULL)); /* Acquire the slot so we "own" it */ - ReplicationSlotAcquire(NameStr(*slotname), true); + ReplicationSlotAcquire(NameStr(*slotname), true, true); /* A slot whose restart_lsn has never been reserved cannot be advanced */ if (XLogRecPtrIsInvalid(MyReplicationSlot->data.restart_lsn)) diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index bc40c454de..96eeb8b7d2 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -846,7 +846,7 @@ StartReplication(StartReplicationCmd *cmd) if (cmd->slotname) { - ReplicationSlotAcquire(cmd->slotname, true); + ReplicationSlotAcquire(cmd->slotname, true, true); if (SlotIsLogical(MyReplicationSlot)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), @@ -1459,7 +1459,7 @@ StartLogicalReplication(StartReplicationCmd *cmd) Assert(!MyReplicationSlot); - ReplicationSlotAcquire(cmd->slotname, true); + ReplicationSlotAcquire(cmd->slotname, true, true); /* * Force a disconnect, so that the decoding code doesn't need to care diff --git a/src/backend/utils/adt/pg_upgrade_support.c b/src/backend/utils/adt/pg_upgrade_support.c index c54b08fe18..82956d58d3 100644 --- a/src/backend/utils/adt/pg_upgrade_support.c +++ b/src/backend/utils/adt/pg_upgrade_support.c @@ -299,7 +299,7 @@ binary_upgrade_logical_slot_has_caught_up(PG_FUNCTION_ARGS) slot_name = PG_GETARG_NAME(0); /* Acquire the given slot */ - ReplicationSlotAcquire(NameStr(*slot_name), true); + ReplicationSlotAcquire(NameStr(*slot_name), true, false); Assert(SlotIsLogical(MyReplicationSlot)); diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c index c12784cbec..4149ff1ffe 100644 --- a/src/backend/utils/misc/guc_tables.c +++ b/src/backend/utils/misc/guc_tables.c @@ -2971,6 +2971,18 @@ struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"replication_slot_inactive_timeout", PGC_SIGHUP, REPLICATION_SENDING, + gettext_noop("Sets the amount of time to wait before invalidating an " + "inactive replication slot."), + NULL, + GUC_UNIT_S + }, + &replication_slot_inactive_timeout, + 0, 0, INT_MAX, + NULL, NULL, NULL + }, + { {"commit_delay", PGC_SUSET, WAL_SETTINGS, gettext_noop("Sets the delay in microseconds between transaction commit and " diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index baecde2841..2e1ad2eaca 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -335,6 +335,7 @@ #wal_sender_timeout = 60s # in milliseconds; 0 disables #track_commit_timestamp = off # collect timestamp of transaction commit # (change requires restart) +#replication_slot_inactive_timeout = 0 # in seconds; 0 disables # - Primary Server - diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h index 7b937d1a0c..f0ac324ce9 100644 --- a/src/include/replication/slot.h +++ b/src/include/replication/slot.h @@ -53,6 +53,8 @@ typedef enum ReplicationSlotInvalidationCause RS_INVAL_HORIZON, /* wal_level insufficient for slot */ RS_INVAL_WAL_LEVEL, + /* inactive slot timeout has occurred */ + RS_INVAL_INACTIVE_TIMEOUT, } ReplicationSlotInvalidationCause; extern PGDLLIMPORT const char *const SlotInvalidationCauses[]; @@ -230,6 +232,7 @@ extern PGDLLIMPORT ReplicationSlot *MyReplicationSlot; /* GUCs */ extern PGDLLIMPORT int max_replication_slots; extern PGDLLIMPORT char *standby_slot_names; +extern PGDLLIMPORT int replication_slot_inactive_timeout; /* shmem initialization functions */ extern Size ReplicationSlotsShmemSize(void); @@ -245,7 +248,8 @@ extern void ReplicationSlotDrop(const char *name, bool nowait); extern void ReplicationSlotDropAcquired(void); extern void ReplicationSlotAlter(const char *name, bool failover); -extern void ReplicationSlotAcquire(const char *name, bool nowait); +extern void ReplicationSlotAcquire(const char *name, bool nowait, + bool check_for_timeout_invalidation); extern void ReplicationSlotRelease(void); extern void ReplicationSlotCleanup(void); extern void ReplicationSlotSave(void); @@ -264,6 +268,8 @@ extern bool InvalidateObsoleteReplicationSlots(ReplicationSlotInvalidationCause XLogSegNo oldestSegno, Oid dboid, TransactionId snapshotConflictHorizon); +extern bool InvalidateInactiveReplicationSlot(ReplicationSlot *slot, + bool persist_state); extern ReplicationSlot *SearchNamedReplicationSlot(const char *name, bool need_lock); extern int ReplicationSlotIndex(ReplicationSlot *slot); extern bool ReplicationSlotName(int index, Name name); diff --git a/src/test/recovery/meson.build b/src/test/recovery/meson.build index 712924c2fa..0437ab5c46 100644 --- a/src/test/recovery/meson.build +++ b/src/test/recovery/meson.build @@ -52,6 +52,7 @@ tests += { 't/041_checkpoint_at_promote.pl', 't/042_low_level_backup.pl', 't/043_wal_replay_wait.pl', + 't/044_invalidate_slots.pl', ], }, } diff --git a/src/test/recovery/t/044_invalidate_slots.pl b/src/test/recovery/t/044_invalidate_slots.pl new file mode 100644 index 0000000000..1e30ea05ef --- /dev/null +++ b/src/test/recovery/t/044_invalidate_slots.pl @@ -0,0 +1,283 @@ +# Copyright (c) 2024, PostgreSQL Global Development Group + +# Test for replication slots invalidation +use strict; +use warnings FATAL => 'all'; + +use PostgreSQL::Test::Utils; +use PostgreSQL::Test::Cluster; +use Test::More; +use Time::HiRes qw(usleep); + +# ============================================================================= +# Testcase start: Invalidate streaming standby's slot as well as logical +# failover slot on primary due to replication_slot_inactive_timeout. Also, +# check the logical failover slot synced on to the standby doesn't invalidate +# the slot on its own, but gets the invalidated state from the remote slot on +# the primary. + +# Initialize primary node +my $primary = PostgreSQL::Test::Cluster->new('primary'); +$primary->init(allows_streaming => 'logical'); + +# Avoid checkpoint during the test, otherwise, the test can get unpredictable +$primary->append_conf( + 'postgresql.conf', q{ +checkpoint_timeout = 1h +autovacuum = off +}); +$primary->start; + +# Take backup +my $backup_name = 'my_backup'; +$primary->backup($backup_name); + +# Create a standby linking to the primary using the replication slot +my $standby1 = PostgreSQL::Test::Cluster->new('standby1'); +$standby1->init_from_backup($primary, $backup_name, has_streaming => 1); + +my $connstr_1 = $primary->connstr; +$standby1->append_conf( + 'postgresql.conf', qq( +hot_standby_feedback = on +primary_slot_name = 'sb1_slot' +primary_conninfo = '$connstr_1 dbname=postgres' +)); + +# Create sync slot on the primary +$primary->psql('postgres', + q{SELECT pg_create_logical_replication_slot('lsub1_sync_slot', 'test_decoding', false, false, true);} +); + +$primary->safe_psql( + 'postgres', qq[ + SELECT pg_create_physical_replication_slot(slot_name := 'sb1_slot'); +]); + +$standby1->start; + +my $standby1_logstart = -s $standby1->logfile; + +# Wait until standby has replayed enough data +$primary->wait_for_catchup($standby1); + +# Synchronize the primary server slots to the standby +$standby1->safe_psql('postgres', "SELECT pg_sync_replication_slots();"); + +# Confirm that the logical failover slot is created on the standby and is +# flagged as 'synced'. +is( $standby1->safe_psql( + 'postgres', + q{SELECT count(*) = 1 FROM pg_replication_slots + WHERE slot_name = 'lsub1_sync_slot' AND synced AND NOT temporary;} + ), + "t", + 'logical slot has synced as true on standby'); + +my $logstart = -s $primary->logfile; +my $inactive_timeout = 2; + +# Set timeout so that the next checkpoint will invalidate the inactive +# replication slot. +$primary->safe_psql( + 'postgres', qq[ + ALTER SYSTEM SET replication_slot_inactive_timeout TO '${inactive_timeout}s'; +]); +$primary->reload; + +# Wait for the logical failover slot to become inactive on the primary. Note +# that nobody has acquired that slot yet, so due to +# replication_slot_inactive_timeout setting above it must get invalidated. +wait_for_slot_invalidation($primary, 'lsub1_sync_slot', $logstart, + $inactive_timeout); + +# Set timeout on the standby also to check the synced slots don't get +# invalidated due to timeout on the standby. +$standby1->safe_psql( + 'postgres', qq[ + ALTER SYSTEM SET replication_slot_inactive_timeout TO '2s'; +]); +$standby1->reload; + +# Now, sync the logical failover slot from the remote slot on the primary. +# Note that the remote slot has already been invalidated due to inactive +# timeout. Now, the standby must also see it as invalidated. +$standby1->safe_psql('postgres', "SELECT pg_sync_replication_slots();"); + +# Wait for the inactive replication slot to be invalidated. +$standby1->poll_query_until( + 'postgres', qq[ + SELECT COUNT(slot_name) = 1 FROM pg_replication_slots + WHERE slot_name = 'lsub1_sync_slot' AND + invalidation_reason = 'inactive_timeout'; +]) + or die + "Timed out while waiting for replication slot lsub1_sync_slot invalidation to be synced on standby"; + +# Synced slot mustn't get invalidated on the standby even after a checkpoint, +# it must sync invalidation from the primary. So, we must not see the slot's +# invalidation message in server log. +$standby1->safe_psql('postgres', "CHECKPOINT"); +ok( !$standby1->log_contains( + "invalidating obsolete replication slot \"lsub1_sync_slot\"", + $standby1_logstart), + 'check that syned slot has not been invalidated on the standby'); + +# Stop standby to make the standby's replication slot on the primary inactive +$standby1->stop; + +# Wait for the standby's replication slot to become inactive +wait_for_slot_invalidation($primary, 'sb1_slot', $logstart, + $inactive_timeout); + +# Testcase end: Invalidate streaming standby's slot as well as logical failover +# slot on primary due to replication_slot_inactive_timeout. Also, check the +# logical failover slot synced on to the standby doesn't invalidate the slot on +# its own, but gets the invalidated state from the remote slot on the primary. +# ============================================================================= + +# ============================================================================= +# Testcase start: Invalidate logical subscriber's slot due to +# replication_slot_inactive_timeout. + +my $publisher = $primary; + +# Prepare for the next test +$publisher->safe_psql( + 'postgres', qq[ + ALTER SYSTEM SET replication_slot_inactive_timeout TO '0'; +]); +$publisher->reload; + +# Create subscriber node +my $subscriber = PostgreSQL::Test::Cluster->new('sub'); +$subscriber->init; +$subscriber->start; + +# Create tables +$publisher->safe_psql('postgres', "CREATE TABLE test_tbl (id int)"); +$subscriber->safe_psql('postgres', "CREATE TABLE test_tbl (id int)"); + +# Insert some data +$subscriber->safe_psql('postgres', + "INSERT INTO test_tbl VALUES (generate_series(1, 5));"); + +# Setup logical replication +my $publisher_connstr = $publisher->connstr . ' dbname=postgres'; +$publisher->safe_psql('postgres', "CREATE PUBLICATION pub FOR ALL TABLES"); +$publisher->safe_psql( + 'postgres', qq[ + SELECT pg_create_logical_replication_slot(slot_name := 'lsub1_slot', plugin := 'pgoutput'); +]); + +$subscriber->safe_psql('postgres', + "CREATE SUBSCRIPTION sub CONNECTION '$publisher_connstr' PUBLICATION pub WITH (slot_name = 'lsub1_slot', create_slot = false)" +); + +$subscriber->wait_for_subscription_sync($publisher, 'sub'); + +my $result = + $subscriber->safe_psql('postgres', "SELECT count(*) FROM test_tbl"); + +is($result, qq(5), "check initial copy was done"); + +# Prepare for the next test +$publisher->safe_psql( + 'postgres', qq[ + ALTER SYSTEM SET replication_slot_inactive_timeout TO ' ${inactive_timeout}s'; +]); +$publisher->reload; + +$logstart = -s $publisher->logfile; + +# Stop subscriber to make the replication slot on publisher inactive +$subscriber->stop; + +# Wait for the replication slot to become inactive and then invalidated due to +# timeout. +wait_for_slot_invalidation($publisher, 'lsub1_slot', $logstart, + $inactive_timeout); + +# Testcase end: Invalidate logical subscriber's slot due to +# replication_slot_inactive_timeout. +# ============================================================================= + +sub wait_for_slot_invalidation +{ + my ($node, $slot_name, $offset, $inactive_timeout) = @_; + my $name = $node->name; + + # Wait for the replication slot to become inactive + $node->poll_query_until( + 'postgres', qq[ + SELECT COUNT(slot_name) = 1 FROM pg_replication_slots + WHERE slot_name = '$slot_name' AND active = 'f'; + ]) + or die + "Timed out while waiting for replication slot to become inactive"; + + # Wait for the replication slot info to be updated + $node->poll_query_until( + 'postgres', qq[ + SELECT COUNT(slot_name) = 1 FROM pg_replication_slots + WHERE inactive_since IS NOT NULL + AND slot_name = '$slot_name' AND active = 'f'; + ]) + or die + "Timed out while waiting for info of replication slot $slot_name to be updated on node $name"; + + # Sleep at least $inactive_timeout duration to avoid multiple checkpoints + # for the slot to get invalidated. + sleep($inactive_timeout); + + check_for_slot_invalidation_in_server_log($node, $slot_name, $offset); + + # Wait for the inactive replication slot to be invalidated + $node->poll_query_until( + 'postgres', qq[ + SELECT COUNT(slot_name) = 1 FROM pg_replication_slots + WHERE slot_name = '$slot_name' AND + invalidation_reason = 'inactive_timeout'; + ]) + or die + "Timed out while waiting for inactive replication slot $slot_name to be invalidated on node $name"; + + # Check that the invalidated slot cannot be acquired + my ($result, $stdout, $stderr); + + ($result, $stdout, $stderr) = $primary->psql( + 'postgres', qq[ + SELECT pg_replication_slot_advance('$slot_name', '0/1'); + ]); + + ok( $stderr =~ + /can no longer get changes from replication slot "$slot_name"/, + "detected error upon trying to acquire invalidated slot $slot_name on node $name" + ) + or die + "could not detect error upon trying to acquire invalidated slot $slot_name"; +} + +# Check for invalidation of slot in server log +sub check_for_slot_invalidation_in_server_log +{ + my ($node, $slot_name, $offset) = @_; + my $invalidated = 0; + + for (my $i = 0; $i < 10 * $PostgreSQL::Test::Utils::timeout_default; $i++) + { + $node->safe_psql('postgres', "CHECKPOINT"); + if ($node->log_contains( + "invalidating obsolete replication slot \"$slot_name\"", + $offset)) + { + $invalidated = 1; + last; + } + usleep(100_000); + } + ok($invalidated, + "check that slot $slot_name invalidation has been logged"); +} + +done_testing(); -- 2.34.1