diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 98b033fc20..12362421d7 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -129,6 +129,7 @@ extern int recoveryTargetAction; extern int recovery_min_apply_delay; extern char *PrimaryConnInfo; extern char *PrimarySlotName; +extern bool wal_receiver_create_temp_slot; /* indirectly set via GUC system */ extern TransactionId recoveryTargetXid; diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h index e08afc6548..cf3e43128c 100644 --- a/src/include/replication/walreceiver.h +++ b/src/include/replication/walreceiver.h @@ -23,7 +23,6 @@ #include "utils/tuplestore.h" /* user-settable parameters */ -extern bool wal_receiver_create_temp_slot; extern int wal_receiver_status_interval; extern int wal_receiver_timeout; extern bool hot_standby_feedback; @@ -321,7 +320,8 @@ extern void ShutdownWalRcv(void); extern bool WalRcvStreaming(void); extern bool WalRcvRunning(void); extern void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr, - const char *conninfo, const char *slotname); + const char *conninfo, const char *slotname, + bool create_temp_slot); extern XLogRecPtr GetWalRcvWriteRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI); extern int GetReplicationApplyDelay(void); extern int GetReplicationTransferLatency(void); diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 3813eadfb4..e0f3ed5c2a 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -283,6 +283,7 @@ bool StandbyModeRequested = false; char *PrimaryConnInfo = NULL; char *PrimarySlotName = NULL; char *PromoteTriggerFile = NULL; +bool wal_receiver_create_temp_slot = false; /* are we currently in standby mode? */ bool StandbyMode = false; @@ -11901,7 +11902,7 @@ WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess, } curFileTLI = tli; RequestXLogStreaming(tli, ptr, PrimaryConnInfo, - PrimarySlotName); + PrimarySlotName, wal_receiver_create_temp_slot); receivedUpto = 0; } diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c index 2ab15c3cbb..ff45482faa 100644 --- a/src/backend/replication/walreceiver.c +++ b/src/backend/replication/walreceiver.c @@ -15,6 +15,12 @@ * WalRcv->receivedUpto variable in shared memory, to inform the startup * process of how far it can proceed with XLOG replay. * + * WAL receivers cannot load directly GUC parameters used when establishing + * their connection to the primary, and rely on parameter values passed down + * by the startup process when WAL streaming is requested. This applies + * to for example the replication slot creation and the connection string to + * use for the connection with the primary. + * * If the primary server ends streaming, but doesn't disconnect, walreceiver * goes into "waiting" mode, and waits for the startup process to give new * instructions. The startup process will treat that the same as @@ -73,7 +79,6 @@ /* GUC variables */ -bool wal_receiver_create_temp_slot; int wal_receiver_status_interval; int wal_receiver_timeout; bool hot_standby_feedback; @@ -348,42 +353,23 @@ WalReceiverMain(void) WalRcvFetchTimeLineHistoryFiles(startpointTLI, primaryTLI); /* - * Create temporary replication slot if no slot name is configured or - * the slot from the previous run was temporary, unless - * wal_receiver_create_temp_slot is disabled. We also need to handle - * the case where the previous run used a temporary slot but - * wal_receiver_create_temp_slot was changed in the meantime. In that - * case, we delete the old slot name in shared memory. (This would + * Create temporary replication slot if requested. In that + * case, we update slot name in shared memory. (This would * all be a bit easier if we just didn't copy the slot name into * shared memory, since we won't need it again later, but then we * can't see the slot name in the stats views.) */ - if (slotname[0] == '\0' || is_temp_slot) + if (is_temp_slot) { - bool changed = false; + snprintf(slotname, sizeof(slotname), + "pg_walreceiver_%lld", + (long long int) walrcv_get_backend_pid(wrconn)); - if (wal_receiver_create_temp_slot) - { - snprintf(slotname, sizeof(slotname), - "pg_walreceiver_%lld", - (long long int) walrcv_get_backend_pid(wrconn)); + walrcv_create_slot(wrconn, slotname, true, 0, NULL); - walrcv_create_slot(wrconn, slotname, true, 0, NULL); - changed = true; - } - else if (slotname[0] != '\0') - { - slotname[0] = '\0'; - changed = true; - } - - if (changed) - { - SpinLockAcquire(&walrcv->mutex); - strlcpy(walrcv->slotname, slotname, NAMEDATALEN); - walrcv->is_temp_slot = wal_receiver_create_temp_slot; - SpinLockRelease(&walrcv->mutex); - } + SpinLockAcquire(&walrcv->mutex); + strlcpy(walrcv->slotname, slotname, NAMEDATALEN); + SpinLockRelease(&walrcv->mutex); } /* diff --git a/src/backend/replication/walreceiverfuncs.c b/src/backend/replication/walreceiverfuncs.c index 89c903e45a..821680a857 100644 --- a/src/backend/replication/walreceiverfuncs.c +++ b/src/backend/replication/walreceiverfuncs.c @@ -215,13 +215,19 @@ ShutdownWalRcv(void) /* * Request postmaster to start walreceiver. * - * recptr indicates the position where streaming should begin, conninfo - * is a libpq connection string to use, and slotname is, optionally, the name - * of a replication slot to acquire. + * "recptr" indicates the position where streaming should begin. "conninfo" + * is a libpq connection string to use. "slotname" is, optionally, the name + * of a replication slot to acquire. "create_temp_slot" indicates to create + * a temporary slot when no "slotname" is given. + * + * WAL receivers do not directly load GUC parameters used for the connection + * to the primary, and rely on the values passed down by the caller of this + * routine instead. Hence, the addition of any new parameters should happen + * through this code path. */ void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr, const char *conninfo, - const char *slotname) + const char *slotname, bool create_temp_slot) { WalRcvData *walrcv = WalRcv; bool launch = false; @@ -248,10 +254,22 @@ RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr, const char *conninfo, else walrcv->conninfo[0] = '\0'; + /* + * Use configured replication slot if present, and ignore the value + * of create_temp_slot as the slot name should be persistent. Otherwise, + * use create_temp_slot to determine whether this WAL receiver should + * create a temporary slot by itself and use it, or not. + */ if (slotname != NULL) + { strlcpy((char *) walrcv->slotname, slotname, NAMEDATALEN); + walrcv->is_temp_slot = false; + } else + { walrcv->slotname[0] = '\0'; + walrcv->is_temp_slot = create_temp_slot; + } if (walrcv->walRcvState == WALRCV_STOPPED) { diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 8228e1f390..ec9cd3696c 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -2029,11 +2029,11 @@ static struct config_bool ConfigureNamesBool[] = }, { - {"wal_receiver_create_temp_slot", PGC_SIGHUP, REPLICATION_STANDBY, + {"wal_receiver_create_temp_slot", PGC_POSTMASTER, REPLICATION_STANDBY, gettext_noop("Sets whether a WAL receiver should create a temporary replication slot if no permanent slot is configured."), }, &wal_receiver_create_temp_slot, - true, + false, NULL, NULL, NULL }, diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index e1048c0047..1dd2a86567 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -321,7 +321,9 @@ #max_standby_streaming_delay = 30s # max delay before canceling queries # when reading streaming WAL; # -1 allows indefinite delay -#wal_receiver_create_temp_slot = on # create temp slot if primary_slot_name not set +#wal_receiver_create_temp_slot = off # Create temp slot if primary_slot_name + # is not set. + # (change requires restart) #wal_receiver_status_interval = 10s # send replies at least this often # 0 disables #hot_standby_feedback = off # send info from standby to prevent diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index c1128f89ec..683d87c491 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -4140,11 +4140,7 @@ ANY num_sync ( ). - The default is on. The only reason to turn this off would be if the - remote instance is currently out of available replication slots. This - parameter can only be set in the postgresql.conf - file or on the server command line. Changes only take effect when the - WAL receiver process starts a new connection. + The default is off. This parameter can only be set at server start.