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help / color / mirror / Atom feedFrom: Zhijie Hou (Fujitsu) <[email protected]>
To: Amit Kapila <[email protected]>
To: shveta malik <[email protected]>
Cc: Ajin Cherian <[email protected]>
Cc: Bertrand Drouvot <[email protected]>
Cc: Masahiko Sawada <[email protected]>
Cc: Dilip Kumar <[email protected]>
Cc: Peter Smith <[email protected]>
Cc: Nisha Moond <[email protected]>
Cc: Hayato Kuroda (Fujitsu) <[email protected]>
Cc: Bharath Rupireddy <[email protected]>
Cc: Peter Eisentraut <[email protected]>
Cc: Bruce Momjian <[email protected]>
Cc: Ashutosh Sharma <[email protected]>
Cc: Andres Freund <[email protected]>
Cc: pgsql-hackers <[email protected]>
Cc: Alvaro Herrera <[email protected]>
Subject: RE: Synchronizing slots from primary to standby
Date: Thu, 25 Jan 2024 02:57:30 +0000
Message-ID: <OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <CAA4eK1Lxvfq9RwOEsguiMCrKPUc1He9UGz1_wi0N0cJaXFa4Eg@mail.gmail.com>
References: <CAJpy0uAwz9iNw3=5QC8S3z8Bf-w0z27rE32SFxjDMer7aTQMPg@mail.gmail.com>
<CAA4eK1+q8R=yEpTMiOZ_Xksdd_Jg3SXvBMxRutHQtkCbdeK_yQ@mail.gmail.com>
<CAJpy0uAU+nzufQwSzyB2YmhPHHn71_=1zkauP4Ra32a_eqbcig@mail.gmail.com>
<CAA4eK1KtwFg6Mr1MRnHUUfPotzc2=5UCTq_D2t8x0PM1Lyhk8g@mail.gmail.com>
<CAD21AoA03f0QKYjiSymGcnROvh1X-3YSqyB-19mkRXt5dfaxFw@mail.gmail.com>
<CAJpy0uCneiKeNuz3B91Wf2LRxAenD3fpaxYfdL09y9qHmvVp+w@mail.gmail.com>
<CAJpy0uCJ7MKgZnKLAACd-AXN0VbWM5gVJ+GRJ1Za_A2UmF3R0A@mail.gmail.com>
<[email protected]>
<CAJpy0uBc6H22RbNVU213AZ_BPw+uDptcTVHakKegpTCv74yN=w@mail.gmail.com>
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<CAFPTHDbsZ+pxAubb9d9BwVNt5OB3_2s77bG6nHcAgUPPhEVmMQ@mail.gmail.com>
<CAJpy0uBqS_HD30mBR0yD1SVCvUZDrw1=dwn1xH8ANEQw7gnPdw@mail.gmail.com>
<CAA4eK1Lxvfq9RwOEsguiMCrKPUc1He9UGz1_wi0N0cJaXFa4Eg@mail.gmail.com>
On Wednesday, January 24, 2024 6:31 PM Amit Kapila <[email protected]> wrote:
>
> On Tue, Jan 23, 2024 at 5:13 PM shveta malik <[email protected]> wrote:
> >
> > Thanks Ajin for testing the patch. PFA v66 which fixes this issue.
> >
>
> I think we should try to commit the patch as all of the design concerns are
> resolved now. To achieve that, can we split the failover setting patch into the
> following: (a) setting failover property via SQL commands and display it in
> pg_replication_slots (b) replication protocol command (c) failover property via
> subscription commands?
>
> It will make each patch smaller and it would be easier to detect any problem in
> the same after commit.
Agreed. I split the original 0001 patch into 3 patches as suggested.
Here is the V68 patch set.
Best Regards,
Hou zj
Attachments:
[application/octet-stream] v68-0005-Slot-sync-worker-as-a-special-process.patch (38.3K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/2-v68-0005-Slot-sync-worker-as-a-special-process.patch)
download | inline diff:
From a0c5734905f01c52ca288fcc146cb7d425c9d52f Mon Sep 17 00:00:00 2001
From: Shveta Malik <[email protected]>
Date: Wed, 24 Jan 2024 16:19:04 +0530
Subject: [PATCH v68 5/8] Slot-sync worker as a special process
This patch attempts to start slot-sync worker as a special process
which is neither a bgworker nor an Auxiliary process. The benefit
we get here is we can control the start-conditions of the worker which
further allows us to define 'enable_syncslot' as PGC_SIGHUP which was
otherwise a PGC_POSTMASTER GUC when slotsync worker was registered as
bgworker.
---
doc/src/sgml/bgworker.sgml | 65 +---
src/backend/postmaster/bgworker.c | 3 -
src/backend/postmaster/postmaster.c | 86 +++--
src/backend/replication/logical/slotsync.c | 360 ++++++++++++++----
src/backend/storage/lmgr/proc.c | 13 +-
src/backend/tcop/postgres.c | 11 -
src/backend/utils/activity/pgstat_io.c | 1 +
.../utils/activity/wait_event_names.txt | 1 +
src/backend/utils/init/miscinit.c | 9 +-
src/backend/utils/init/postinit.c | 8 +-
src/backend/utils/misc/guc_tables.c | 2 +-
src/include/miscadmin.h | 1 +
src/include/postmaster/bgworker.h | 1 -
src/include/replication/worker_internal.h | 8 +-
14 files changed, 387 insertions(+), 182 deletions(-)
diff --git a/doc/src/sgml/bgworker.sgml b/doc/src/sgml/bgworker.sgml
index a7cfe6c58c..2c393385a9 100644
--- a/doc/src/sgml/bgworker.sgml
+++ b/doc/src/sgml/bgworker.sgml
@@ -114,59 +114,18 @@ typedef struct BackgroundWorker
<para>
<structfield>bgw_start_time</structfield> is the server state during which
- <command>postgres</command> should start the process. Note that this setting
- only indicates when the processes are to be started; they do not stop when
- a different state is reached. Possible values are:
-
- <variablelist>
- <varlistentry>
- <term><literal>BgWorkerStart_PostmasterStart</literal></term>
- <listitem>
- <para>
- <indexterm><primary>BgWorkerStart_PostmasterStart</primary></indexterm>
- Start as soon as postgres itself has finished its own initialization;
- processes requesting this are not eligible for database connections.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><literal>BgWorkerStart_ConsistentState</literal></term>
- <listitem>
- <para>
- <indexterm><primary>BgWorkerStart_ConsistentState</primary></indexterm>
- Start as soon as a consistent state has been reached in a hot-standby,
- allowing processes to connect to databases and run read-only queries.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><literal>BgWorkerStart_ConsistentState_HotStandby</literal></term>
- <listitem>
- <para>
- <indexterm><primary>BgWorkerStart_ConsistentState_HotStandby</primary></indexterm>
- Same meaning as <literal>BgWorkerStart_ConsistentState</literal> but
- it is more strict in terms of the server i.e. start the worker only
- if it is hot-standby.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><literal>BgWorkerStart_RecoveryFinished</literal></term>
- <listitem>
- <para>
- <indexterm><primary>BgWorkerStart_RecoveryFinished</primary></indexterm>
- Start as soon as the system has entered normal read-write state. Note
- that the <literal>BgWorkerStart_ConsistentState</literal> and
- <literal>BgWorkerStart_RecoveryFinished</literal> are equivalent
- in a server that's not a hot standby.
- </para>
- </listitem>
- </varlistentry>
-
- </variablelist>
+ <command>postgres</command> should start the process; it can be one of
+ <literal>BgWorkerStart_PostmasterStart</literal> (start as soon as
+ <command>postgres</command> itself has finished its own initialization; processes
+ requesting this are not eligible for database connections),
+ <literal>BgWorkerStart_ConsistentState</literal> (start as soon as a consistent state
+ has been reached in a hot standby, allowing processes to connect to
+ databases and run read-only queries), and
+ <literal>BgWorkerStart_RecoveryFinished</literal> (start as soon as the system has
+ entered normal read-write state). Note the last two values are equivalent
+ in a server that's not a hot standby. Note that this setting only indicates
+ when the processes are to be started; they do not stop when a different state
+ is reached.
</para>
<para>
diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c
index 46828b8a89..1add449f7c 100644
--- a/src/backend/postmaster/bgworker.c
+++ b/src/backend/postmaster/bgworker.c
@@ -130,9 +130,6 @@ static const struct
{
"ApplyWorkerMain", ApplyWorkerMain
},
- {
- "ReplSlotSyncWorkerMain", ReplSlotSyncWorkerMain
- },
{
"ParallelApplyWorkerMain", ParallelApplyWorkerMain
},
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d90d5d1576..adfaf75cf9 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -168,11 +168,11 @@
* they will never become live backends. dead_end children are not assigned a
* PMChildSlot. dead_end children have bkend_type NORMAL.
*
- * "Special" children such as the startup, bgwriter and autovacuum launcher
- * tasks are not in this list. They are tracked via StartupPID and other
- * pid_t variables below. (Thus, there can't be more than one of any given
- * "special" child process type. We use BackendList entries for any child
- * process there can be more than one of.)
+ * "Special" children such as the startup, bgwriter, autovacuum launcher and
+ * slot sync worker tasks are not in this list. They are tracked via StartupPID
+ * and other pid_t variables below. (Thus, there can't be more than one of any
+ * given "special" child process type. We use BackendList entries for any
+ * child process there can be more than one of.)
*/
typedef struct bkend
{
@@ -255,7 +255,8 @@ static pid_t StartupPID = 0,
WalSummarizerPID = 0,
AutoVacPID = 0,
PgArchPID = 0,
- SysLoggerPID = 0;
+ SysLoggerPID = 0,
+ SlotSyncWorkerPID = 0;
/* Startup process's status */
typedef enum
@@ -459,6 +460,10 @@ static void InitPostmasterDeathWatchHandle(void);
(pmState == PM_RECOVERY || pmState == PM_HOT_STANDBY))) && \
PgArchCanRestart())
+#define SlotSyncWorkerAllowed() \
+ (enable_syncslot && pmState == PM_HOT_STANDBY && \
+ SlotSyncWorkerCanRestart())
+
#ifdef EXEC_BACKEND
#ifdef WIN32
@@ -1011,12 +1016,6 @@ PostmasterMain(int argc, char *argv[])
*/
ApplyLauncherRegister();
- /*
- * Register the slot sync worker here to kick start slot-sync operation
- * sooner on the physical standby.
- */
- SlotSyncWorkerRegister();
-
/*
* process any libraries that should be preloaded at postmaster start
*/
@@ -1837,6 +1836,10 @@ ServerLoop(void)
if (PgArchPID == 0 && PgArchStartupAllowed())
PgArchPID = StartArchiver();
+ /* If we need to start a slot sync worker, try to do that now */
+ if (SlotSyncWorkerPID == 0 && SlotSyncWorkerAllowed())
+ SlotSyncWorkerPID = StartSlotSyncWorker();
+
/* If we need to signal the autovacuum launcher, do so now */
if (avlauncher_needs_signal)
{
@@ -2684,6 +2687,8 @@ process_pm_reload_request(void)
signal_child(PgArchPID, SIGHUP);
if (SysLoggerPID != 0)
signal_child(SysLoggerPID, SIGHUP);
+ if (SlotSyncWorkerPID != 0)
+ signal_child(SlotSyncWorkerPID, SIGHUP);
/* Reload authentication config files too */
if (!load_hba())
@@ -3041,6 +3046,8 @@ process_pm_child_exit(void)
AutoVacPID = StartAutoVacLauncher();
if (PgArchStartupAllowed() && PgArchPID == 0)
PgArchPID = StartArchiver();
+ if (SlotSyncWorkerAllowed() && SlotSyncWorkerPID == 0)
+ SlotSyncWorkerPID = StartSlotSyncWorker();
/* workers may be scheduled to start now */
maybe_start_bgworkers();
@@ -3211,6 +3218,22 @@ process_pm_child_exit(void)
continue;
}
+ /*
+ * Was it the slot sync worker? Normal exit or FATAL exit can be
+ * ignored (FATAL can be caused by libpqwalreceiver on receiving
+ * shutdown request by the startup process during promotion); we'll
+ * start a new one at the next iteration of the postmaster's main
+ * loop, if necessary. Any other exit condition is treated as a crash.
+ */
+ if (pid == SlotSyncWorkerPID)
+ {
+ SlotSyncWorkerPID = 0;
+ if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
+ HandleChildCrash(pid, exitstatus,
+ _("slot sync worker process"));
+ continue;
+ }
+
/* Was it one of our background workers? */
if (CleanupBackgroundWorker(pid, exitstatus))
{
@@ -3577,6 +3600,12 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
else if (PgArchPID != 0 && take_action)
sigquit_child(PgArchPID);
+ /* Take care of the slot sync worker too */
+ if (pid == SlotSyncWorkerPID)
+ SlotSyncWorkerPID = 0;
+ else if (SlotSyncWorkerPID != 0 && take_action)
+ sigquit_child(SlotSyncWorkerPID);
+
/* We do NOT restart the syslogger */
if (Shutdown != ImmediateShutdown)
@@ -3717,6 +3746,8 @@ PostmasterStateMachine(void)
signal_child(WalReceiverPID, SIGTERM);
if (WalSummarizerPID != 0)
signal_child(WalSummarizerPID, SIGTERM);
+ if (SlotSyncWorkerPID != 0)
+ signal_child(SlotSyncWorkerPID, SIGTERM);
/* checkpointer, archiver, stats, and syslogger may continue for now */
/* Now transition to PM_WAIT_BACKENDS state to wait for them to die */
@@ -3732,13 +3763,13 @@ PostmasterStateMachine(void)
/*
* PM_WAIT_BACKENDS state ends when we have no regular backends
* (including autovac workers), no bgworkers (including unconnected
- * ones), and no walwriter, autovac launcher or bgwriter. If we are
- * doing crash recovery or an immediate shutdown then we expect the
- * checkpointer to exit as well, otherwise not. The stats and
- * syslogger processes are disregarded since they are not connected to
- * shared memory; we also disregard dead_end children here. Walsenders
- * and archiver are also disregarded, they will be terminated later
- * after writing the checkpoint record.
+ * ones), and no walwriter, autovac launcher, bgwriter or slot sync
+ * worker. If we are doing crash recovery or an immediate shutdown
+ * then we expect the checkpointer to exit as well, otherwise not. The
+ * stats and syslogger processes are disregarded since they are not
+ * connected to shared memory; we also disregard dead_end children
+ * here. Walsenders and archiver are also disregarded, they will be
+ * terminated later after writing the checkpoint record.
*/
if (CountChildren(BACKEND_TYPE_ALL - BACKEND_TYPE_WALSND) == 0 &&
StartupPID == 0 &&
@@ -3748,7 +3779,8 @@ PostmasterStateMachine(void)
(CheckpointerPID == 0 ||
(!FatalError && Shutdown < ImmediateShutdown)) &&
WalWriterPID == 0 &&
- AutoVacPID == 0)
+ AutoVacPID == 0 &&
+ SlotSyncWorkerPID == 0)
{
if (Shutdown >= ImmediateShutdown || FatalError)
{
@@ -3846,6 +3878,7 @@ PostmasterStateMachine(void)
Assert(CheckpointerPID == 0);
Assert(WalWriterPID == 0);
Assert(AutoVacPID == 0);
+ Assert(SlotSyncWorkerPID == 0);
/* syslogger is not considered here */
pmState = PM_NO_CHILDREN;
}
@@ -4069,6 +4102,8 @@ TerminateChildren(int signal)
signal_child(AutoVacPID, signal);
if (PgArchPID != 0)
signal_child(PgArchPID, signal);
+ if (SlotSyncWorkerPID != 0)
+ signal_child(SlotSyncWorkerPID, signal);
}
/*
@@ -4881,6 +4916,7 @@ SubPostmasterMain(int argc, char *argv[])
*/
if (strcmp(argv[1], "--forkbackend") == 0 ||
strcmp(argv[1], "--forkavlauncher") == 0 ||
+ strcmp(argv[1], "--forkssworker") == 0 ||
strcmp(argv[1], "--forkavworker") == 0 ||
strcmp(argv[1], "--forkaux") == 0 ||
strcmp(argv[1], "--forkbgworker") == 0)
@@ -4984,6 +5020,13 @@ SubPostmasterMain(int argc, char *argv[])
AutoVacWorkerMain(argc - 2, argv + 2); /* does not return */
}
+ if (strcmp(argv[1], "--forkssworker") == 0)
+ {
+ /* Restore basic shared memory pointers */
+ InitShmemAccess(UsedShmemSegAddr);
+
+ ReplSlotSyncWorkerMain(argc - 2, argv + 2); /* does not return */
+ }
if (strcmp(argv[1], "--forkbgworker") == 0)
{
/* do this as early as possible; in particular, before InitProcess() */
@@ -5806,9 +5849,6 @@ bgworker_should_start_now(BgWorkerStartTime start_time)
case PM_HOT_STANDBY:
if (start_time == BgWorkerStart_ConsistentState)
return true;
- if (start_time == BgWorkerStart_ConsistentState_HotStandby &&
- pmState != PM_RUN)
- return true;
/* fall through */
case PM_RECOVERY:
diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c
index 84b66104f7..2a033647b3 100644
--- a/src/backend/replication/logical/slotsync.c
+++ b/src/backend/replication/logical/slotsync.c
@@ -40,9 +40,12 @@
#include "access/xlogrecovery.h"
#include "catalog/pg_database.h"
#include "commands/dbcommands.h"
+#include "libpq/pqsignal.h"
#include "pgstat.h"
#include "postmaster/bgworker.h"
+#include "postmaster/fork_process.h"
#include "postmaster/interrupt.h"
+#include "postmaster/postmaster.h"
#include "replication/logical.h"
#include "replication/logicallauncher.h"
#include "replication/logicalworker.h"
@@ -55,6 +58,8 @@
#include "utils/fmgroids.h"
#include "utils/guc_hooks.h"
#include "utils/pg_lsn.h"
+#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/varlena.h"
/*
@@ -98,7 +103,8 @@ SlotSyncWorkerCtxStruct *SlotSyncWorker = NULL;
/* GUC variable */
bool enable_syncslot = false;
-/* The sleep time (ms) between slot-sync cycles varies dynamically
+/*
+ * The sleep time (ms) between slot-sync cycles varies dynamically
* (within a MIN/MAX range) according to slot activity. See
* wait_for_slot_activity() for details.
*/
@@ -107,8 +113,16 @@ bool enable_syncslot = false;
static long sleep_ms = MIN_WORKER_NAPTIME_MS;
+/* Flag to tell if we are in a slot sync worker process */
+static bool am_slotsync_worker = false;
+
static void ProcessSlotSyncInterrupts(WalReceiverConn *wrconn);
+#ifdef EXEC_BACKEND
+static pid_t slotsyncworker_forkexec(void);
+#endif
+NON_EXEC_STATIC void ReplSlotSyncWorkerMain(int argc, char *argv[]) pg_attribute_noreturn();
+
/*
* If necessary, update local slot metadata based on the data from the remote
* slot.
@@ -712,7 +726,8 @@ synchronize_slots(WalReceiverConn *wrconn)
* standbys.
*/
static void
-check_primary_info(WalReceiverConn *wrconn, bool *am_cascading_standby)
+check_primary_info(WalReceiverConn *wrconn, bool *am_cascading_standby,
+ bool *primary_slot_invalid)
{
#define PRIMARY_INFO_OUTPUT_COL_COUNT 2
WalRcvExecResult *res;
@@ -727,8 +742,10 @@ check_primary_info(WalReceiverConn *wrconn, bool *am_cascading_standby)
StartTransactionCommand();
Assert(am_cascading_standby != NULL);
+ Assert(primary_slot_invalid != NULL);
*am_cascading_standby = false; /* overwritten later if cascading */
+ *primary_slot_invalid = false; /* overwritten later if invalid */
initStringInfo(&cmd);
appendStringInfo(&cmd,
@@ -766,13 +783,16 @@ check_primary_info(WalReceiverConn *wrconn, bool *am_cascading_standby)
Assert(!isnull);
if (!valid)
- ereport(ERROR,
+ {
+ *primary_slot_invalid = true;
+ ereport(LOG,
errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("exiting from slot synchronization due to bad configuration"),
+ errmsg("bad configuration for slot synchronization"),
/* translator: second %s is a GUC variable name */
errdetail("The primary server slot \"%s\" specified by"
" \"%s\" is not valid.",
PrimarySlotName, "primary_slot_name"));
+ }
}
ExecClearTuple(tupslot);
@@ -781,20 +801,15 @@ check_primary_info(WalReceiverConn *wrconn, bool *am_cascading_standby)
}
/*
- * Check that all necessary GUCs for slot synchronization are set
- * appropriately. If not, raise an ERROR.
+ * Returns true if all necessary GUCs for slot synchronization are set
+ * appropriately, otherwise returns false.
*
* If all checks pass, extracts the dbname from the primary_conninfo GUC and
- * returns it.
+ * and return it in output dbname arg.
*/
-static char *
-validate_parameters_and_get_dbname(void)
+static bool
+validate_parameters_and_get_dbname(char **dbname)
{
- char *dbname;
-
- /* Sanity check. */
- Assert(enable_syncslot);
-
/*
* A physical replication slot(primary_slot_name) is required on the
* primary to ensure that the rows needed by the standby are not removed
@@ -802,10 +817,13 @@ validate_parameters_and_get_dbname(void)
* be invalidated.
*/
if (PrimarySlotName == NULL || strcmp(PrimarySlotName, "") == 0)
- ereport(ERROR,
+ {
+ ereport(LOG,
/* translator: %s is a GUC variable name */
- errmsg("exiting from slot synchronization due to bad configuration"),
+ errmsg("bad configuration for slot synchronization"),
errhint("\"%s\" must be defined.", "primary_slot_name"));
+ return false;
+ }
/*
* hot_standby_feedback must be enabled to cooperate with the physical
@@ -813,45 +831,94 @@ validate_parameters_and_get_dbname(void)
* catalog_xmin values on the standby.
*/
if (!hot_standby_feedback)
- ereport(ERROR,
+ {
+ ereport(LOG,
/* translator: %s is a GUC variable name */
- errmsg("exiting from slot synchronization due to bad configuration"),
+ errmsg("bad configuration for slot synchronization"),
errhint("\"%s\" must be enabled.", "hot_standby_feedback"));
+ return false;
+ }
/*
* Logical decoding requires wal_level >= logical and we currently only
* synchronize logical slots.
*/
if (wal_level < WAL_LEVEL_LOGICAL)
- ereport(ERROR,
- /* translator: %s is a GUC variable name */
- errmsg("exiting from slot synchronization due to bad configuration"),
+ {
+ ereport(LOG,
+ errmsg("bad configuration for slot synchronization"),
errhint("\"wal_level\" must be >= logical."));
+ return false;
+ }
/*
* The primary_conninfo is required to make connection to primary for
* getting slots information.
*/
if (PrimaryConnInfo == NULL || strcmp(PrimaryConnInfo, "") == 0)
- ereport(ERROR,
+ {
+ ereport(LOG,
/* translator: %s is a GUC variable name */
- errmsg("exiting from slot synchronization due to bad configuration"),
+ errmsg("bad configuration for slot synchronization"),
errhint("\"%s\" must be defined.", "primary_conninfo"));
+ return false;
+ }
/*
* The slot sync worker needs a database connection for walrcv_exec to
* work.
*/
- dbname = walrcv_get_dbname_from_conninfo(PrimaryConnInfo);
- if (dbname == NULL)
- ereport(ERROR,
+ *dbname = walrcv_get_dbname_from_conninfo(PrimaryConnInfo);
+ if (*dbname == NULL)
+ {
+ ereport(LOG,
/*
* translator: 'dbname' is a specific option; %s is a GUC variable
* name
*/
- errmsg("exiting from slot synchronization due to bad configuration"),
+ errmsg("bad configuration for slot synchronization"),
errhint("'dbname' must be specified in \"%s\".", "primary_conninfo"));
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * Check that all necessary GUCs for slot synchronization are set
+ * appropriately. If not, sleep for MAX_WORKER_NAPTIME_MS and check again.
+ * The idea is to become no-op until we get valid GUCs values.
+ *
+ * If all checks pass, extracts the dbname from the primary_conninfo GUC and
+ * returns it.
+ */
+static char *
+wait_for_valid_params_and_get_dbname(void)
+{
+ char *dbname;
+ int rc;
+
+ /* Sanity check. */
+ Assert(enable_syncslot);
+
+ for (;;)
+ {
+ if (validate_parameters_and_get_dbname(&dbname))
+ break;
+
+ ereport(LOG, errmsg("skipping slot synchronization"));
+
+ ProcessSlotSyncInterrupts(NULL);
+
+ rc = WaitLatch(MyLatch,
+ WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
+ MAX_WORKER_NAPTIME_MS,
+ WAIT_EVENT_REPL_SLOTSYNC_MAIN);
+
+ if (rc & WL_LATCH_SET)
+ ResetLatch(MyLatch);
+ }
return dbname;
}
@@ -867,16 +934,28 @@ slotsync_reread_config(void)
{
char *old_primary_conninfo = pstrdup(PrimaryConnInfo);
char *old_primary_slotname = pstrdup(PrimarySlotName);
+ bool old_enable_syncslot = enable_syncslot;
bool old_hot_standby_feedback = hot_standby_feedback;
bool conninfo_changed;
bool primary_slotname_changed;
+ Assert(enable_syncslot);
+
ConfigReloadPending = false;
ProcessConfigFile(PGC_SIGHUP);
conninfo_changed = strcmp(old_primary_conninfo, PrimaryConnInfo) != 0;
primary_slotname_changed = strcmp(old_primary_slotname, PrimarySlotName) != 0;
+ if (old_enable_syncslot != enable_syncslot)
+ {
+ ereport(LOG,
+ /* translator: %s is a GUC variable name */
+ errmsg("slot sync worker will shutdown because"
+ " %s is disabled", "enable_syncslot"));
+ proc_exit(0);
+ }
+
if (conninfo_changed ||
primary_slotname_changed ||
(old_hot_standby_feedback != hot_standby_feedback))
@@ -884,8 +963,7 @@ slotsync_reread_config(void)
ereport(LOG,
errmsg("slot sync worker will restart because of a parameter change"));
- /* The exit code 1 will make postmaster restart this worker */
- proc_exit(1);
+ proc_exit(0);
}
pfree(old_primary_conninfo);
@@ -902,7 +980,8 @@ ProcessSlotSyncInterrupts(WalReceiverConn *wrconn)
if (ShutdownRequestPending)
{
- walrcv_disconnect(wrconn);
+ if (wrconn)
+ walrcv_disconnect(wrconn);
ereport(LOG,
errmsg("replication slot sync worker is shutting down on receiving SIGINT"));
proc_exit(0);
@@ -934,17 +1013,16 @@ slotsync_worker_onexit(int code, Datum arg)
* sync-cycles is reset to the minimum (200ms).
*/
static void
-wait_for_slot_activity(bool some_slot_updated, bool am_cascading_standby)
+wait_for_slot_activity(bool some_slot_updated, bool recheck_primary_info)
{
int rc;
- if (am_cascading_standby)
+ if (recheck_primary_info)
{
/*
- * Slot synchronization is currently not supported on cascading
- * standby. So if we are on the cascading standby, we will skip the
- * sync and take a longer nap before we check again whether we are
- * still cascading standby or not.
+ * If we are on the cascading standby or primary_slot_name configured
+ * is not valid, then we will skip the sync and take a longer nap
+ * before we can do check_primary_info() again.
*/
sleep_ms = MAX_WORKER_NAPTIME_MS;
}
@@ -980,20 +1058,38 @@ wait_for_slot_activity(bool some_slot_updated, bool am_cascading_standby)
* It connects to the primary server, fetches logical failover slots
* information periodically in order to create and sync the slots.
*/
-void
-ReplSlotSyncWorkerMain(Datum main_arg)
+NON_EXEC_STATIC void
+ReplSlotSyncWorkerMain(int argc, char *argv[])
{
WalReceiverConn *wrconn = NULL;
char *dbname;
bool am_cascading_standby;
+ bool primary_slot_invalid;
char *err;
+ sigjmp_buf local_sigjmp_buf;
- ereport(LOG, errmsg("replication slot sync worker started"));
+ am_slotsync_worker = true;
- on_shmem_exit(slotsync_worker_onexit, (Datum) 0);
+ MyBackendType = B_SLOTSYNC_WORKER;
- SpinLockAcquire(&SlotSyncWorker->mutex);
+ init_ps_display(NULL);
+
+ SetProcessingMode(InitProcessing);
+ /*
+ * Create a per-backend PGPROC struct in shared memory. We must do this
+ * before we access any shared memory.
+ */
+ InitProcess();
+
+ /*
+ * Early initialization.
+ */
+ BaseInit();
+
+ Assert(SlotSyncWorker != NULL);
+
+ SpinLockAcquire(&SlotSyncWorker->mutex);
Assert(SlotSyncWorker->pid == InvalidPid);
/*
@@ -1008,26 +1104,77 @@ ReplSlotSyncWorkerMain(Datum main_arg)
/* Advertise our PID so that the startup process can kill us on promotion */
SlotSyncWorker->pid = MyProcPid;
-
SpinLockRelease(&SlotSyncWorker->mutex);
+ ereport(LOG, errmsg("replication slot sync worker started"));
+
+ on_shmem_exit(slotsync_worker_onexit, (Datum) 0);
+
/* Setup signal handling */
pqsignal(SIGHUP, SignalHandlerForConfigReload);
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, die);
- BackgroundWorkerUnblockSignals();
+ pqsignal(SIGFPE, FloatExceptionHandler);
+ pqsignal(SIGUSR1, procsignal_sigusr1_handler);
+ pqsignal(SIGUSR2, SIG_IGN);
+ pqsignal(SIGPIPE, SIG_IGN);
+ pqsignal(SIGCHLD, SIG_DFL);
+
+ /*
+ * Establishes SIGALRM handler and initialize timeout module. It is needed
+ * by InitPostgres to register different timeouts.
+ */
+ InitializeTimeouts();
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
- dbname = validate_parameters_and_get_dbname();
+ /*
+ * If an exception is encountered, processing resumes here.
+ *
+ * We just need to clean up, report the error, and go away.
+ *
+ * If we do not have this handling here, then since this worker process
+ * operates at the bottom of the exception stack, ERRORs turn into FATALs.
+ * Therefore, we create our own exception handler to catch ERRORs.
+ */
+ if (sigsetjmp(local_sigjmp_buf, 1) != 0)
+ {
+ /* since not using PG_TRY, must reset error stack by hand */
+ error_context_stack = NULL;
+
+ /* Prevents interrupts while cleaning up */
+ HOLD_INTERRUPTS();
+
+ /* Report the error to the server log */
+ EmitErrorReport();
+
+ /*
+ * We can now go away. Note that because we called InitProcess, a
+ * callback was registered to do ProcKill, which will clean up
+ * necessary state.
+ */
+ proc_exit(0);
+ }
+
+ /* We can now handle ereport(ERROR) */
+ PG_exception_stack = &local_sigjmp_buf;
+
+ /*
+ * Unblock signals (they were blocked when the postmaster forked us)
+ */
+ sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
+
+ dbname = wait_for_valid_params_and_get_dbname();
/*
* Connect to the database specified by user in primary_conninfo. We need
* a database connection for walrcv_exec to work. Please see comments atop
* libpqrcv_exec.
*/
- BackgroundWorkerInitializeConnection(dbname, NULL, 0);
+ InitPostgres(dbname, InvalidOid, NULL, InvalidOid, 0, NULL);
+
+ SetProcessingMode(NormalProcessing);
/*
* Establish the connection to the primary server for slots
@@ -1046,26 +1193,29 @@ ReplSlotSyncWorkerMain(Datum main_arg)
* cascading standby and validates primary_slot_name for
* non-cascading-standbys.
*/
- check_primary_info(wrconn, &am_cascading_standby);
+ check_primary_info(wrconn, &am_cascading_standby, &primary_slot_invalid);
/* Main wait loop */
for (;;)
{
bool some_slot_updated = false;
+ bool recheck_primary_info = am_cascading_standby || primary_slot_invalid;
ProcessSlotSyncInterrupts(wrconn);
- if (!am_cascading_standby)
+ if (!recheck_primary_info)
some_slot_updated = synchronize_slots(wrconn);
+ else if (primary_slot_invalid)
+ ereport(LOG, errmsg("skipping slot synchronization"));
- wait_for_slot_activity(some_slot_updated, am_cascading_standby);
+ wait_for_slot_activity(some_slot_updated, recheck_primary_info);
/*
* If the standby was promoted then what was previously a cascading
* standby might no longer be one, so recheck each time.
*/
- if (am_cascading_standby)
- check_primary_info(wrconn, &am_cascading_standby);
+ if (recheck_primary_info)
+ check_primary_info(wrconn, &am_cascading_standby, &primary_slot_invalid);
}
/*
@@ -1081,7 +1231,7 @@ ReplSlotSyncWorkerMain(Datum main_arg)
bool
IsLogicalSlotSyncWorker(void)
{
- return SlotSyncWorker->pid == MyProcPid;
+ return am_slotsync_worker;
}
/*
@@ -1111,7 +1261,7 @@ ShutDownSlotSync(void)
/* Wait a bit, we don't expect to have to wait long */
rc = WaitLatch(MyLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
- 10L, WAIT_EVENT_BGWORKER_SHUTDOWN);
+ 10L, WAIT_EVENT_REPL_SLOTSYNC_SHUTDOWN);
if (rc & WL_LATCH_SET)
{
@@ -1154,42 +1304,92 @@ SlotSyncWorkerShmemInit(void)
}
}
+#ifdef EXEC_BACKEND
/*
- * Register the background worker for slots synchronization provided
- * enable_syncslot is ON.
+ * The forkexec routine for the slot sync worker process.
+ *
+ * Format up the arglist, then fork and exec.
*/
-void
-SlotSyncWorkerRegister(void)
+static pid_t
+slotsyncworker_forkexec(void)
{
- BackgroundWorker bgw;
+ char *av[10];
+ int ac = 0;
- if (!enable_syncslot)
- {
- ereport(LOG,
- errmsg("skipping slot synchronization"),
- errdetail("\"enable_syncslot\" is disabled."));
- return;
- }
+ av[ac++] = "postgres";
+ av[ac++] = "--forkssworker";
+ av[ac++] = NULL; /* filled in by postmaster_forkexec */
+ av[ac] = NULL;
- memset(&bgw, 0, sizeof(bgw));
+ Assert(ac < lengthof(av));
- /* We need database connection which needs shared-memory access as well */
- bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
- BGWORKER_BACKEND_DATABASE_CONNECTION;
+ return postmaster_forkexec(ac, av);
+}
+#endif
- /* Start as soon as a consistent state has been reached in a hot standby */
- bgw.bgw_start_time = BgWorkerStart_ConsistentState_HotStandby;
+/*
+ * SlotSyncWorkerCanRestart
+ *
+ * Returns true if the worker is allowed to restart if enough time has
+ * passed (SLOTSYNC_RESTART_INTERVAL_SEC) since it was launched last.
+ * Otherwise returns false.
+ *
+ * This is a safety valve to protect against continuous respawn attempts if the
+ * worker is dying immediately at launch. Note that since we will retry to
+ * launch the worker from the postmaster main loop, we will get another
+ * chance later.
+ */
+bool
+SlotSyncWorkerCanRestart(void)
+{
+#define SLOTSYNC_RESTART_INTERVAL_SEC 10
- snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
- snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ReplSlotSyncWorkerMain");
- snprintf(bgw.bgw_name, BGW_MAXLEN,
- "replication slot sync worker");
- snprintf(bgw.bgw_type, BGW_MAXLEN,
- "slot sync worker");
+ static time_t last_slotsync_start_time = 0;
+ time_t curtime = time(NULL);
- bgw.bgw_restart_time = BGW_DEFAULT_RESTART_INTERVAL;
- bgw.bgw_notify_pid = 0;
- bgw.bgw_main_arg = (Datum) 0;
+ /* Return false if too soon since last start. */
+ if ((unsigned int) (curtime - last_slotsync_start_time) <
+ (unsigned int) SLOTSYNC_RESTART_INTERVAL_SEC)
+ return false;
+
+ last_slotsync_start_time = curtime;
+ return true;
+}
+
+/*
+ * Main entry point for slot sync worker process, to be called from the
+ * postmaster.
+ */
+int
+StartSlotSyncWorker(void)
+{
+ pid_t pid;
+
+#ifdef EXEC_BACKEND
+ switch ((pid = slotsyncworker_forkexec()))
+ {
+#else
+ switch ((pid = fork_process()))
+ {
+ case 0:
+ /* in postmaster child ... */
+ InitPostmasterChild();
+
+ /* Close the postmaster's sockets */
+ ClosePostmasterPorts(false);
+
+ ReplSlotSyncWorkerMain(0, NULL);
+ break;
+#endif
+ case -1:
+ ereport(LOG,
+ (errmsg("could not fork slot sync worker process: %m")));
+ return 0;
+
+ default:
+ return (int) pid;
+ }
- RegisterBackgroundWorker(&bgw);
+ /* shouldn't get here */
+ return 0;
}
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 4ad96beb87..aa53a57077 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -42,6 +42,7 @@
#include "replication/slot.h"
#include "replication/syncrep.h"
#include "replication/walsender.h"
+#include "replication/logicalworker.h"
#include "storage/condition_variable.h"
#include "storage/ipc.h"
#include "storage/lmgr.h"
@@ -364,8 +365,12 @@ InitProcess(void)
* child; this is so that the postmaster can detect it if we exit without
* cleaning up. (XXX autovac launcher currently doesn't participate in
* this; it probably should.)
+ *
+ * Slot sync worker also does not participate in it, see comments atop
+ * 'struct bkend' in postmaster.c.
*/
- if (IsUnderPostmaster && !IsAutoVacuumLauncherProcess())
+ if (IsUnderPostmaster && !IsAutoVacuumLauncherProcess() &&
+ !IsLogicalSlotSyncWorker())
MarkPostmasterChildActive();
/*
@@ -934,8 +939,12 @@ ProcKill(int code, Datum arg)
* This process is no longer present in shared memory in any meaningful
* way, so tell the postmaster we've cleaned up acceptably well. (XXX
* autovac launcher should be included here someday)
+ *
+ * Slot sync worker is also not a postmaster child, so skip this shared
+ * memory related processing here.
*/
- if (IsUnderPostmaster && !IsAutoVacuumLauncherProcess())
+ if (IsUnderPostmaster && !IsAutoVacuumLauncherProcess() &&
+ !IsLogicalSlotSyncWorker())
MarkPostmasterChildInactive();
/* wake autovac launcher if needed -- see comments in FreeWorkerInfo */
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e8c530acd9..1a34bd3715 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3286,17 +3286,6 @@ ProcessInterrupts(void)
*/
proc_exit(1);
}
- else if (IsLogicalSlotSyncWorker())
- {
- elog(DEBUG1,
- "replication slot sync worker is shutting down due to administrator command");
-
- /*
- * Slot sync worker can be stopped at any time. Use exit status 1
- * so the background worker is restarted.
- */
- proc_exit(1);
- }
else if (IsBackgroundWorker)
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 43c393d6fe..9d6e067382 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -338,6 +338,7 @@ pgstat_tracks_io_bktype(BackendType bktype)
case B_BG_WORKER:
case B_BG_WRITER:
case B_CHECKPOINTER:
+ case B_SLOTSYNC_WORKER:
case B_STANDALONE_BACKEND:
case B_STARTUP:
case B_WAL_SENDER:
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index 3e6203322a..4c0ee2dd29 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -54,6 +54,7 @@ LOGICAL_LAUNCHER_MAIN "Waiting in main loop of logical replication launcher proc
LOGICAL_PARALLEL_APPLY_MAIN "Waiting in main loop of logical replication parallel apply process."
RECOVERY_WAL_STREAM "Waiting in main loop of startup process for WAL to arrive, during streaming recovery."
REPL_SLOTSYNC_MAIN "Waiting in main loop of slot sync worker."
+REPL_SLOTSYNC_SHUTDOWN "Waiting for slot sync worker to shut down."
SYSLOGGER_MAIN "Waiting in main loop of syslogger process."
WAL_RECEIVER_MAIN "Waiting in main loop of WAL receiver process."
WAL_SENDER_MAIN "Waiting in main loop of WAL sender process."
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index 23f77a59e5..309aa33a62 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -40,6 +40,7 @@
#include "postmaster/interrupt.h"
#include "postmaster/pgarch.h"
#include "postmaster/postmaster.h"
+#include "replication/logicalworker.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/latch.h"
@@ -293,6 +294,9 @@ GetBackendTypeDesc(BackendType backendType)
case B_LOGGER:
backendDesc = "logger";
break;
+ case B_SLOTSYNC_WORKER:
+ backendDesc = "slotsyncworker";
+ break;
case B_STANDALONE_BACKEND:
backendDesc = "standalone backend";
break;
@@ -835,9 +839,10 @@ InitializeSessionUserIdStandalone(void)
{
/*
* This function should only be called in single-user mode, in autovacuum
- * workers, and in background workers.
+ * workers, in slot sync worker and in background workers.
*/
- Assert(!IsUnderPostmaster || IsAutoVacuumWorkerProcess() || IsBackgroundWorker);
+ Assert(!IsUnderPostmaster || IsAutoVacuumWorkerProcess() ||
+ IsLogicalSlotSyncWorker() || IsBackgroundWorker);
/* call only once */
Assert(!OidIsValid(AuthenticatedUserId));
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 1ad3367159..a5af0f410a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -43,6 +43,7 @@
#include "postmaster/autovacuum.h"
#include "postmaster/postmaster.h"
#include "replication/slot.h"
+#include "replication/logicalworker.h"
#include "replication/walsender.h"
#include "storage/bufmgr.h"
#include "storage/fd.h"
@@ -874,10 +875,11 @@ InitPostgres(const char *in_dbname, Oid dboid,
* Perform client authentication if necessary, then figure out our
* postgres user ID, and see if we are a superuser.
*
- * In standalone mode and in autovacuum worker processes, we use a fixed
- * ID, otherwise we figure it out from the authenticated user name.
+ * In standalone mode, autovacuum worker processes and slot sync worker
+ * process, we use a fixed ID, otherwise we figure it out from the
+ * authenticated user name.
*/
- if (bootstrap || IsAutoVacuumWorkerProcess())
+ if (bootstrap || IsAutoVacuumWorkerProcess() || IsLogicalSlotSyncWorker())
{
InitializeSessionUserIdStandalone();
am_superuser = true;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index fe044c16de..3af11b2b80 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -2056,7 +2056,7 @@ struct config_bool ConfigureNamesBool[] =
},
{
- {"enable_syncslot", PGC_POSTMASTER, REPLICATION_STANDBY,
+ {"enable_syncslot", PGC_SIGHUP, REPLICATION_STANDBY,
gettext_noop("Enables a physical standby to synchronize logical failover slots from the primary server."),
},
&enable_syncslot,
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 0b01c1f093..65819cb7a7 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -332,6 +332,7 @@ typedef enum BackendType
B_BG_WRITER,
B_CHECKPOINTER,
B_LOGGER,
+ B_SLOTSYNC_WORKER,
B_STANDALONE_BACKEND,
B_STARTUP,
B_WAL_RECEIVER,
diff --git a/src/include/postmaster/bgworker.h b/src/include/postmaster/bgworker.h
index 7092fc72c6..22fc49ec27 100644
--- a/src/include/postmaster/bgworker.h
+++ b/src/include/postmaster/bgworker.h
@@ -79,7 +79,6 @@ typedef enum
BgWorkerStart_PostmasterStart,
BgWorkerStart_ConsistentState,
BgWorkerStart_RecoveryFinished,
- BgWorkerStart_ConsistentState_HotStandby,
} BgWorkerStartTime;
#define BGW_DEFAULT_RESTART_INTERVAL 60
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 2167720971..aa01f63648 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -329,9 +329,11 @@ extern void pa_decr_and_wait_stream_block(void);
extern void pa_xact_finish(ParallelApplyWorkerInfo *winfo,
XLogRecPtr remote_lsn);
-
-extern void ReplSlotSyncWorkerMain(Datum main_arg);
-extern void SlotSyncWorkerRegister(void);
+#ifdef EXEC_BACKEND
+extern void ReplSlotSyncWorkerMain(int argc, char *argv[]) pg_attribute_noreturn();
+#endif
+extern int StartSlotSyncWorker(void);
+extern bool SlotSyncWorkerCanRestart(void);
extern void ShutDownSlotSync(void);
extern void SlotSyncWorkerShmemInit(void);
--
2.30.0.windows.2
[application/octet-stream] v68-0006-Allow-logical-walsenders-to-wait-for-the-physica.patch (40.7K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/3-v68-0006-Allow-logical-walsenders-to-wait-for-the-physica.patch)
download | inline diff:
From 3255cfcd01df176f9673ab33fa62e76e799d1cad Mon Sep 17 00:00:00 2001
From: Shveta Malik <[email protected]>
Date: Mon, 22 Jan 2024 15:49:49 +0530
Subject: [PATCH v68 6/8] Allow logical walsenders to wait for the physical
This patch introduces a mechanism to ensure that physical standby servers,
which are potential failover candidates, have received and flushed changes
before making them visible to subscribers. By doing so, it guarantees that
the promoted standby server is not lagging behind the subscribers when a
failover is necessary.
A new parameter named standby_slot_names is introduced. The logical
walsender now guarantees that all local changes are sent and flushed to
the standby servers corresponding to the replication slots specified in
standby_slot_names before sending those changes to the subscriber.
Additionally, The SQL functions pg_logical_slot_get_changes and
pg_replication_slot_advance are modified to wait for the replication slots
mentioned in standby_slot_names to catch up before returning the changes
to the user.
---
doc/src/sgml/config.sgml | 24 ++
doc/src/sgml/logicaldecoding.sgml | 9 +-
.../replication/logical/logicalfuncs.c | 13 +
src/backend/replication/slot.c | 342 +++++++++++++++++-
src/backend/replication/slotfuncs.c | 9 +
src/backend/replication/walsender.c | 111 +++++-
.../utils/activity/wait_event_names.txt | 1 +
src/backend/utils/misc/guc_tables.c | 14 +
src/backend/utils/misc/postgresql.conf.sample | 2 +
src/include/replication/slot.h | 7 +
src/include/replication/walsender.h | 1 +
src/include/replication/walsender_private.h | 7 +
src/include/utils/guc_hooks.h | 3 +
src/test/recovery/meson.build | 1 +
src/test/recovery/t/006_logical_decoding.pl | 3 +-
.../t/050_standby_failover_slots_sync.pl | 232 ++++++++++--
16 files changed, 738 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index bd2d2f871e..76345e433c 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -4420,6 +4420,30 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows
</listitem>
</varlistentry>
+ <varlistentry id="guc-standby-slot-names" xreflabel="standby_slot_names">
+ <term><varname>standby_slot_names</varname> (<type>string</type>)
+ <indexterm>
+ <primary><varname>standby_slot_names</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ List of physical slots guarantees that logical replication slots with
+ failover enabled do not consume changes until those changes are received
+ and flushed to corresponding physical standbys. If a logical replication
+ connection is meant to switch to a physical standby after the standby is
+ promoted, the physical replication slot for the standby should be listed
+ here.
+ </para>
+ <para>
+ The standbys corresponding to the physical replication slots in
+ <varname>standby_slot_names</varname> must configure
+ <literal>enable_syncslot = true</literal> so they can receive
+ failover logical slots changes from the primary.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect2>
diff --git a/doc/src/sgml/logicaldecoding.sgml b/doc/src/sgml/logicaldecoding.sgml
index ec14cf7325..965ee716e2 100644
--- a/doc/src/sgml/logicaldecoding.sgml
+++ b/doc/src/sgml/logicaldecoding.sgml
@@ -372,7 +372,14 @@ postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NU
to work, it is mandatory to have a physical replication slot between the
primary and the standby, and
<link linkend="guc-hot-standby-feedback"><varname>hot_standby_feedback</varname></link>
- must be enabled on the standby.
+ must be enabled on the standby. It's also highly recommended that the said
+ physical replication slot is named in
+ <link linkend="guc-standby-slot-names"><varname>standby_slot_names</varname></link>
+ list on the primary, to prevent the subscriber from consuming changes
+ faster than the hot standby. But once we configure it, then certain latency
+ is expected in sending changes to logical subscribers due to wait on
+ physical replication slots in
+ <link linkend="guc-standby-slot-names"><varname>standby_slot_names</varname></link>
</para>
<para>
diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c
index b0081d3ce5..5ff761dd65 100644
--- a/src/backend/replication/logical/logicalfuncs.c
+++ b/src/backend/replication/logical/logicalfuncs.c
@@ -30,6 +30,7 @@
#include "replication/decode.h"
#include "replication/logical.h"
#include "replication/message.h"
+#include "replication/walsender.h"
#include "storage/fd.h"
#include "utils/array.h"
#include "utils/builtins.h"
@@ -109,6 +110,7 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
MemoryContext per_query_ctx;
MemoryContext oldcontext;
XLogRecPtr end_of_wal;
+ XLogRecPtr wait_for_wal_lsn;
LogicalDecodingContext *ctx;
ResourceOwner old_resowner = CurrentResourceOwner;
ArrayType *arr;
@@ -228,6 +230,17 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
NameStr(MyReplicationSlot->data.plugin),
format_procedure(fcinfo->flinfo->fn_oid))));
+ if (XLogRecPtrIsInvalid(upto_lsn))
+ wait_for_wal_lsn = end_of_wal;
+ else
+ wait_for_wal_lsn = Min(upto_lsn, end_of_wal);
+
+ /*
+ * Wait for specified streaming replication standby servers (if any)
+ * to confirm receipt of WAL up to wait_for_wal_lsn.
+ */
+ WaitForStandbyConfirmation(wait_for_wal_lsn);
+
ctx->output_writer_private = p;
/*
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index f07147a68a..a7c1eb84aa 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -46,13 +46,18 @@
#include "common/string.h"
#include "miscadmin.h"
#include "pgstat.h"
+#include "postmaster/interrupt.h"
#include "replication/slot.h"
#include "replication/walsender.h"
+#include "replication/walsender_private.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "utils/builtins.h"
+#include "utils/guc_hooks.h"
+#include "utils/memutils.h"
+#include "utils/varlena.h"
/*
* Replication slot on-disk data structure.
@@ -99,10 +104,19 @@ ReplicationSlotCtlData *ReplicationSlotCtl = NULL;
/* My backend's replication slot in the shared memory array */
ReplicationSlot *MyReplicationSlot = NULL;
-/* GUC variable */
+/* GUC variables */
int max_replication_slots = 10; /* the maximum number of replication
* slots */
+/*
+ * This GUC lists streaming replication standby server slot names that
+ * logical WAL sender processes will wait for.
+ */
+char *standby_slot_names;
+
+/* This is parsed and cached list for raw standby_slot_names. */
+static List *standby_slot_names_list = NIL;
+
static void ReplicationSlotShmemExit(int code, Datum arg);
static void ReplicationSlotDropPtr(ReplicationSlot *slot);
@@ -2233,3 +2247,329 @@ RestoreSlotFromDisk(const char *name)
(errmsg("too many replication slots active before shutdown"),
errhint("Increase max_replication_slots and try again.")));
}
+
+/*
+ * A helper function to validate slots specified in GUC standby_slot_names.
+ */
+static bool
+validate_standby_slots(char **newval)
+{
+ char *rawname;
+ List *elemlist;
+ ListCell *lc;
+ bool ok;
+
+ /* Need a modifiable copy of string */
+ rawname = pstrdup(*newval);
+
+ /* Verify syntax and parse string into a list of identifiers */
+ ok = SplitIdentifierString(rawname, ',', &elemlist);
+
+ if (!ok)
+ GUC_check_errdetail("List syntax is invalid.");
+
+ /*
+ * If there is a syntax error in the name or if the replication slots'
+ * data is not initialized yet (i.e., we are in the startup process), skip
+ * the slot verification.
+ */
+ if (!ok || !ReplicationSlotCtl)
+ {
+ pfree(rawname);
+ list_free(elemlist);
+ return ok;
+ }
+
+ foreach(lc, elemlist)
+ {
+ char *name = lfirst(lc);
+ ReplicationSlot *slot;
+
+ slot = SearchNamedReplicationSlot(name, true);
+
+ if (!slot)
+ {
+ GUC_check_errdetail("replication slot \"%s\" does not exist",
+ name);
+ ok = false;
+ break;
+ }
+
+ if (!SlotIsPhysical(slot))
+ {
+ GUC_check_errdetail("\"%s\" is not a physical replication slot",
+ name);
+ ok = false;
+ break;
+ }
+ }
+
+ pfree(rawname);
+ list_free(elemlist);
+ return ok;
+}
+
+/*
+ * GUC check_hook for standby_slot_names
+ */
+bool
+check_standby_slot_names(char **newval, void **extra, GucSource source)
+{
+ if (strcmp(*newval, "") == 0)
+ return true;
+
+ /*
+ * "*" is not accepted as in that case primary will not be able to know
+ * for which all standbys to wait for. Even if we have physical-slots
+ * info, there is no way to confirm whether there is any standby
+ * configured for the known physical slots.
+ */
+ if (strcmp(*newval, "*") == 0)
+ {
+ GUC_check_errdetail("\"%s\" is not accepted for standby_slot_names",
+ *newval);
+ return false;
+ }
+
+ /* Now verify if the specified slots really exist and have correct type */
+ if (!validate_standby_slots(newval))
+ return false;
+
+ *extra = guc_strdup(ERROR, *newval);
+
+ return true;
+}
+
+/*
+ * GUC assign_hook for standby_slot_names
+ */
+void
+assign_standby_slot_names(const char *newval, void *extra)
+{
+ List *standby_slots;
+ MemoryContext oldcxt;
+ char *standby_slot_names_cpy = extra;
+
+ list_free(standby_slot_names_list);
+ standby_slot_names_list = NIL;
+
+ /* No value is specified for standby_slot_names. */
+ if (standby_slot_names_cpy == NULL)
+ return;
+
+ if (!SplitIdentifierString(standby_slot_names_cpy, ',', &standby_slots))
+ {
+ /* This should not happen if GUC checked check_standby_slot_names. */
+ elog(ERROR, "invalid list syntax");
+ }
+
+ /*
+ * Switch to the same memory context under which GUC variables are
+ * allocated (GUCMemoryContext).
+ */
+ oldcxt = MemoryContextSwitchTo(GetMemoryChunkContext(standby_slot_names_cpy));
+ standby_slot_names_list = list_copy(standby_slots);
+ MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Return a copy of standby_slot_names_list if the copy flag is set to true,
+ * otherwise return the original list.
+ */
+List *
+GetStandbySlotList(bool copy)
+{
+ /*
+ * Since we do not support syncing slots to cascading standbys, we return
+ * NIL here if we are running in a standby to indicate that no standby
+ * slots need to be waited for.
+ */
+ if (RecoveryInProgress())
+ return NIL;
+
+ if (copy)
+ return list_copy(standby_slot_names_list);
+ else
+ return standby_slot_names_list;
+}
+
+/*
+ * Reload the config file and reinitialize the standby slot list if the GUC
+ * standby_slot_names has changed.
+ */
+void
+RereadConfigAndReInitSlotList(List **standby_slots)
+{
+ char *pre_standby_slot_names;
+
+ /*
+ * If we are running on a standby, there is no need to reload
+ * standby_slot_names since we do not support syncing slots to cascading
+ * standbys.
+ */
+ if (RecoveryInProgress())
+ {
+ ProcessConfigFile(PGC_SIGHUP);
+ return;
+ }
+
+ pre_standby_slot_names = pstrdup(standby_slot_names);
+
+ ProcessConfigFile(PGC_SIGHUP);
+
+ if (strcmp(pre_standby_slot_names, standby_slot_names) != 0)
+ {
+ list_free(*standby_slots);
+ *standby_slots = GetStandbySlotList(true);
+ }
+
+ pfree(pre_standby_slot_names);
+}
+
+/*
+ * Filter the standby slots based on the specified log sequence number
+ * (wait_for_lsn).
+ *
+ * This function updates the passed standby_slots list, removing any slots that
+ * have already caught up to or surpassed the given wait_for_lsn. Additionally,
+ * it removes slots that have been invalidated, dropped, or converted to
+ * logical slots.
+ */
+void
+FilterStandbySlots(XLogRecPtr wait_for_lsn, List **standby_slots)
+{
+ ListCell *lc;
+ List *standby_slots_cpy = *standby_slots;
+
+ foreach(lc, standby_slots_cpy)
+ {
+ char *name = lfirst(lc);
+ char *warningfmt = NULL;
+ ReplicationSlot *slot;
+
+ slot = SearchNamedReplicationSlot(name, true);
+
+ if (!slot)
+ {
+ /*
+ * It may happen that the slot specified in standby_slot_names GUC
+ * value is dropped, so let's skip over it.
+ */
+ warningfmt = _("replication slot \"%s\" specified in parameter \"%s\" does not exist, ignoring");
+ }
+ else if (SlotIsLogical(slot))
+ {
+ /*
+ * If a logical slot name is provided in standby_slot_names, issue
+ * a WARNING and skip it. Although logical slots are disallowed in
+ * the GUC check_hook(validate_standby_slots), it is still
+ * possible for a user to drop an existing physical slot and
+ * recreate a logical slot with the same name. Since it is
+ * harmless, a WARNING should be enough, no need to error-out.
+ */
+ warningfmt = _("cannot have logical replication slot \"%s\" in parameter \"%s\", ignoring");
+ }
+ else
+ {
+ SpinLockAcquire(&slot->mutex);
+
+ if (slot->data.invalidated != RS_INVAL_NONE)
+ {
+ /*
+ * Specified physical slot have been invalidated, so no point
+ * in waiting for it.
+ */
+ warningfmt = _("physical slot \"%s\" specified in parameter \"%s\" has been invalidated, ignoring");
+ }
+ else if (XLogRecPtrIsInvalid(slot->data.restart_lsn) ||
+ slot->data.restart_lsn < wait_for_lsn)
+ {
+ bool inactive = (slot->active_pid == 0);
+
+ SpinLockRelease(&slot->mutex);
+
+ /* Log warning if no active_pid for this physical slot */
+ if (inactive)
+ ereport(WARNING,
+ errmsg("replication slot \"%s\" specified in parameter \"%s\" does not have active_pid",
+ name, "standby_slot_names"),
+ errdetail("Logical replication is waiting on the "
+ "standby associated with \"%s\".", name),
+ errhint("Consider starting standby associated with "
+ "\"%s\" or amend standby_slot_names.", name));
+
+ /* Continue if the current slot hasn't caught up. */
+ continue;
+ }
+ else
+ {
+ Assert(slot->data.restart_lsn >= wait_for_lsn);
+ }
+
+ SpinLockRelease(&slot->mutex);
+ }
+
+ /*
+ * Reaching here indicates that either the slot has passed the
+ * wait_for_lsn or there is an issue with the slot that requires a
+ * warning to be reported.
+ */
+ if (warningfmt)
+ ereport(WARNING, errmsg(warningfmt, name, "standby_slot_names"));
+
+ standby_slots_cpy = foreach_delete_current(standby_slots_cpy, lc);
+ }
+
+ *standby_slots = standby_slots_cpy;
+}
+
+/*
+ * Wait for physical standby to confirm receiving the given lsn.
+ *
+ * Used by logical decoding SQL functions that acquired slot with failover
+ * enabled. It waits for physical standbys corresponding to the physical slots
+ * specified in the standby_slot_names GUC.
+ */
+void
+WaitForStandbyConfirmation(XLogRecPtr wait_for_lsn)
+{
+ List *standby_slots;
+
+ if (!MyReplicationSlot->data.failover)
+ return;
+
+ standby_slots = GetStandbySlotList(true);
+
+ if (standby_slots == NIL)
+ return;
+
+ ConditionVariablePrepareToSleep(&WalSndCtl->wal_confirm_rcv_cv);
+
+ for (;;)
+ {
+ CHECK_FOR_INTERRUPTS();
+
+ if (ConfigReloadPending)
+ {
+ ConfigReloadPending = false;
+ RereadConfigAndReInitSlotList(&standby_slots);
+ }
+
+ FilterStandbySlots(wait_for_lsn, &standby_slots);
+
+ /* Exit if done waiting for every slot. */
+ if (standby_slots == NIL)
+ break;
+
+ /*
+ * We wait for the slots in the standby_slot_names to catch up, but we
+ * use a timeout so we can also check the if the standby_slot_names has
+ * been changed.
+ */
+ ConditionVariableTimedSleep(&WalSndCtl->wal_confirm_rcv_cv, 1000,
+ WAIT_EVENT_WAIT_FOR_STANDBY_CONFIRMATION);
+ }
+
+ ConditionVariableCancelSleep();
+ list_free(standby_slots);
+}
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index 843ae8cd68..0a09b6c508 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -21,6 +21,7 @@
#include "replication/decode.h"
#include "replication/logical.h"
#include "replication/slot.h"
+#include "replication/walsender.h"
#include "utils/builtins.h"
#include "utils/inval.h"
#include "utils/pg_lsn.h"
@@ -474,6 +475,8 @@ pg_physical_replication_slot_advance(XLogRecPtr moveto)
* crash, but this makes the data consistent after a clean shutdown.
*/
ReplicationSlotMarkDirty();
+
+ PhysicalWakeupLogicalWalSnd();
}
return retlsn;
@@ -514,6 +517,12 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
.segment_close = wal_segment_close),
NULL, NULL, NULL);
+ /*
+ * Wait for specified streaming replication standby servers (if any)
+ * to confirm receipt of WAL up to moveto lsn.
+ */
+ WaitForStandbyConfirmation(moveto);
+
/*
* Start reading at the slot's restart_lsn, which we know to point to
* a valid record.
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index f753aed345..71933f4bf1 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1219,7 +1219,6 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
parseCreateReplSlotOptions(cmd, &reserve_wal, &snapshot_action, &two_phase,
&failover);
-
if (cmd->kind == REPLICATION_KIND_PHYSICAL)
{
ReplicationSlotCreate(cmd->slotname, false,
@@ -1728,27 +1727,78 @@ WalSndUpdateProgress(LogicalDecodingContext *ctx, XLogRecPtr lsn, TransactionId
ProcessPendingWrites();
}
+/*
+ * Wake up the logical walsender processes with failover-enabled slots if the
+ * currently acquired physical slot is specified in standby_slot_names
+ * GUC.
+ */
+void
+PhysicalWakeupLogicalWalSnd(void)
+{
+ ListCell *lc;
+ List *standby_slots;
+
+ Assert(MyReplicationSlot && SlotIsPhysical(MyReplicationSlot));
+
+ standby_slots = GetStandbySlotList(false);
+
+ foreach(lc, standby_slots)
+ {
+ char *name = lfirst(lc);
+
+ if (strcmp(name, NameStr(MyReplicationSlot->data.name)) == 0)
+ {
+ ConditionVariableBroadcast(&WalSndCtl->wal_confirm_rcv_cv);
+ return;
+ }
+ }
+}
+
/*
* Wait till WAL < loc is flushed to disk so it can be safely sent to client.
*
- * Returns end LSN of flushed WAL. Normally this will be >= loc, but
- * if we detect a shutdown request (either from postmaster or client)
- * we will return early, so caller must always check.
+ * If the walsender holds a logical slot that has enabled failover, we also
+ * wait for all the specified streaming replication standby servers to
+ * confirm receipt of WAL up to RecentFlushPtr.
+ *
+ * Returns end LSN of flushed WAL. Normally this will be >= loc, but if we
+ * detect a shutdown request (either from postmaster or client) we will return
+ * early, so caller must always check.
*/
static XLogRecPtr
WalSndWaitForWal(XLogRecPtr loc)
{
int wakeEvents;
+ bool wait_for_standby = false;
+ uint32 wait_event;
+ List *standby_slots = NIL;
static XLogRecPtr RecentFlushPtr = InvalidXLogRecPtr;
+ if (MyReplicationSlot->data.failover && replication_active)
+ standby_slots = GetStandbySlotList(true);
+
/*
- * Fast path to avoid acquiring the spinlock in case we already know we
- * have enough WAL available. This is particularly interesting if we're
- * far behind.
+ * Check if all the standby servers have confirmed receipt of WAL up to
+ * RecentFlushPtr even when we already know we have enough WAL available.
+ *
+ * Note that we cannot directly return without checking the status of
+ * standby servers because the standby_slot_names may have changed, which
+ * means there could be new standby slots in the list that have not yet
+ * caught up to the RecentFlushPtr.
*/
- if (RecentFlushPtr != InvalidXLogRecPtr &&
- loc <= RecentFlushPtr)
- return RecentFlushPtr;
+ if (!XLogRecPtrIsInvalid(RecentFlushPtr) && loc <= RecentFlushPtr)
+ {
+ FilterStandbySlots(RecentFlushPtr, &standby_slots);
+
+ /*
+ * Fast path to avoid acquiring the spinlock in case we already know
+ * we have enough WAL available and all the standby servers have
+ * confirmed receipt of WAL up to RecentFlushPtr. This is particularly
+ * interesting if we're far behind.
+ */
+ if (standby_slots == NIL)
+ return RecentFlushPtr;
+ }
/* Get a more recent flush pointer. */
if (!RecoveryInProgress())
@@ -1769,7 +1819,7 @@ WalSndWaitForWal(XLogRecPtr loc)
if (ConfigReloadPending)
{
ConfigReloadPending = false;
- ProcessConfigFile(PGC_SIGHUP);
+ RereadConfigAndReInitSlotList(&standby_slots);
SyncRepInitConfig();
}
@@ -1784,8 +1834,18 @@ WalSndWaitForWal(XLogRecPtr loc)
if (got_STOPPING)
XLogBackgroundFlush();
+ /*
+ * Update the standby slots that have not yet caught up to the flushed
+ * position. It is good to wait up to RecentFlushPtr and then let it
+ * send the changes to logical subscribers one by one which are
+ * already covered in RecentFlushPtr without needing to wait on every
+ * change for standby confirmation.
+ */
+ if (wait_for_standby)
+ FilterStandbySlots(RecentFlushPtr, &standby_slots);
+
/* Update our idea of the currently flushed position. */
- if (!RecoveryInProgress())
+ else if (!RecoveryInProgress())
RecentFlushPtr = GetFlushRecPtr(NULL);
else
RecentFlushPtr = GetXLogReplayRecPtr(NULL);
@@ -1813,9 +1873,18 @@ WalSndWaitForWal(XLogRecPtr loc)
!waiting_for_ping_response)
WalSndKeepalive(false, InvalidXLogRecPtr);
- /* check whether we're done */
- if (loc <= RecentFlushPtr)
+ if (loc > RecentFlushPtr)
+ wait_event = WAIT_EVENT_WAL_SENDER_WAIT_FOR_WAL;
+ else if (standby_slots)
+ {
+ wait_event = WAIT_EVENT_WAIT_FOR_STANDBY_CONFIRMATION;
+ wait_for_standby = true;
+ }
+ else
+ {
+ /* Already caught up and doesn't need to wait for standby_slots. */
break;
+ }
/* Waiting for new WAL. Since we need to wait, we're now caught up. */
WalSndCaughtUp = true;
@@ -1855,9 +1924,11 @@ WalSndWaitForWal(XLogRecPtr loc)
if (pq_is_send_pending())
wakeEvents |= WL_SOCKET_WRITEABLE;
- WalSndWait(wakeEvents, sleeptime, WAIT_EVENT_WAL_SENDER_WAIT_FOR_WAL);
+ WalSndWait(wakeEvents, sleeptime, wait_event);
}
+ list_free(standby_slots);
+
/* reactivate latch so WalSndLoop knows to continue */
SetLatch(MyLatch);
return RecentFlushPtr;
@@ -2265,6 +2336,7 @@ PhysicalConfirmReceivedLocation(XLogRecPtr lsn)
{
ReplicationSlotMarkDirty();
ReplicationSlotsComputeRequiredLSN();
+ PhysicalWakeupLogicalWalSnd();
}
/*
@@ -3532,6 +3604,7 @@ WalSndShmemInit(void)
ConditionVariableInit(&WalSndCtl->wal_flush_cv);
ConditionVariableInit(&WalSndCtl->wal_replay_cv);
+ ConditionVariableInit(&WalSndCtl->wal_confirm_rcv_cv);
}
}
@@ -3601,8 +3674,14 @@ WalSndWait(uint32 socket_events, long timeout, uint32 wait_event)
*
* And, we use separate shared memory CVs for physical and logical
* walsenders for selective wake ups, see WalSndWakeup() for more details.
+ *
+ * If the wait event is WAIT_FOR_STANDBY_CONFIRMATION, wait on another CV
+ * until awakened by physical walsenders after the walreceiver confirms the
+ * receipt of the LSN.
*/
- if (MyWalSnd->kind == REPLICATION_KIND_PHYSICAL)
+ if (wait_event == WAIT_EVENT_WAIT_FOR_STANDBY_CONFIRMATION)
+ ConditionVariablePrepareToSleep(&WalSndCtl->wal_confirm_rcv_cv);
+ else if (MyWalSnd->kind == REPLICATION_KIND_PHYSICAL)
ConditionVariablePrepareToSleep(&WalSndCtl->wal_flush_cv);
else if (MyWalSnd->kind == REPLICATION_KIND_LOGICAL)
ConditionVariablePrepareToSleep(&WalSndCtl->wal_replay_cv);
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index 4c0ee2dd29..9973ef41b9 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -78,6 +78,7 @@ GSS_OPEN_SERVER "Waiting to read data from the client while establishing a GSSAP
LIBPQWALRECEIVER_CONNECT "Waiting in WAL receiver to establish connection to remote server."
LIBPQWALRECEIVER_RECEIVE "Waiting in WAL receiver to receive data from remote server."
SSL_OPEN_SERVER "Waiting for SSL while attempting connection."
+WAIT_FOR_STANDBY_CONFIRMATION "Waiting for the WAL to be received by physical standby."
WAL_SENDER_WAIT_FOR_WAL "Waiting for WAL to be flushed in WAL sender process."
WAL_SENDER_WRITE_DATA "Waiting for any activity when processing replies from WAL receiver in WAL sender process."
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 3af11b2b80..a82618c3d4 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -4628,6 +4628,20 @@ struct config_string ConfigureNamesString[] =
check_debug_io_direct, assign_debug_io_direct, NULL
},
+ {
+ {"standby_slot_names", PGC_SIGHUP, REPLICATION_PRIMARY,
+ gettext_noop("Lists streaming replication standby server slot "
+ "names that logical WAL sender processes will wait for."),
+ gettext_noop("Decoded changes are sent out to plugins by logical "
+ "WAL sender processes only after specified "
+ "replication slots confirm receiving WAL."),
+ GUC_LIST_INPUT | GUC_LIST_QUOTE
+ },
+ &standby_slot_names,
+ "",
+ check_standby_slot_names, assign_standby_slot_names, NULL
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL, NULL
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 3868694d3f..db4afaf356 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -334,6 +334,8 @@
# method to choose sync standbys, number of sync standbys,
# and comma-separated list of application_name
# from standby(s); '*' = all
+#standby_slot_names = '' # streaming replication standby server slot names that
+ # logical walsender processes will wait for
# - Standby Servers -
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 41f0cc35f3..a0bad469fd 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -229,6 +229,7 @@ extern PGDLLIMPORT ReplicationSlot *MyReplicationSlot;
/* GUCs */
extern PGDLLIMPORT int max_replication_slots;
+extern PGDLLIMPORT char *standby_slot_names;
/* shmem initialization functions */
extern Size ReplicationSlotsShmemSize(void);
@@ -275,4 +276,10 @@ extern void CheckPointReplicationSlots(bool is_shutdown);
extern void CheckSlotRequirements(void);
extern void CheckSlotPermissions(void);
+extern List *GetStandbySlotList(bool copy);
+extern void WaitForStandbyConfirmation(XLogRecPtr wait_for_lsn);
+extern void FilterStandbySlots(XLogRecPtr wait_for_lsn,
+ List **standby_slots);
+extern void RereadConfigAndReInitSlotList(List **standby_slots);
+
#endif /* SLOT_H */
diff --git a/src/include/replication/walsender.h b/src/include/replication/walsender.h
index 276d8913aa..f9a559f831 100644
--- a/src/include/replication/walsender.h
+++ b/src/include/replication/walsender.h
@@ -47,6 +47,7 @@ extern void WalSndInitStopping(void);
extern void WalSndWaitStopping(void);
extern void HandleWalSndInitStopping(void);
extern void WalSndRqstFileReload(void);
+extern void PhysicalWakeupLogicalWalSnd(void);
extern XLogRecPtr GetStandbyFlushRecPtr(TimeLineID *tli);
/*
diff --git a/src/include/replication/walsender_private.h b/src/include/replication/walsender_private.h
index 3113e9ea47..0f962b0c72 100644
--- a/src/include/replication/walsender_private.h
+++ b/src/include/replication/walsender_private.h
@@ -113,6 +113,13 @@ typedef struct
ConditionVariable wal_flush_cv;
ConditionVariable wal_replay_cv;
+ /*
+ * Used by physical walsenders holding slots specified in
+ * standby_slot_names to wake up logical walsenders holding
+ * failover-enabled slots when a walreceiver confirms the receipt of LSN.
+ */
+ ConditionVariable wal_confirm_rcv_cv;
+
WalSnd walsnds[FLEXIBLE_ARRAY_MEMBER];
} WalSndCtlData;
diff --git a/src/include/utils/guc_hooks.h b/src/include/utils/guc_hooks.h
index 5300c44f3b..464996b4f0 100644
--- a/src/include/utils/guc_hooks.h
+++ b/src/include/utils/guc_hooks.h
@@ -162,5 +162,8 @@ extern bool check_wal_consistency_checking(char **newval, void **extra,
extern void assign_wal_consistency_checking(const char *newval, void *extra);
extern bool check_wal_segment_size(int *newval, void **extra, GucSource source);
extern void assign_wal_sync_method(int new_wal_sync_method, void *extra);
+extern bool check_standby_slot_names(char **newval, void **extra,
+ GucSource source);
+extern void assign_standby_slot_names(const char *newval, void *extra);
#endif /* GUC_HOOKS_H */
diff --git a/src/test/recovery/meson.build b/src/test/recovery/meson.build
index 88fb0306f5..4152c07318 100644
--- a/src/test/recovery/meson.build
+++ b/src/test/recovery/meson.build
@@ -45,6 +45,7 @@ tests += {
't/037_invalid_database.pl',
't/038_save_logical_slots_shutdown.pl',
't/039_end_of_wal.pl',
+ 't/050_standby_failover_slots_sync.pl',
],
},
}
diff --git a/src/test/recovery/t/006_logical_decoding.pl b/src/test/recovery/t/006_logical_decoding.pl
index 5c7b4ca5e3..85f019774c 100644
--- a/src/test/recovery/t/006_logical_decoding.pl
+++ b/src/test/recovery/t/006_logical_decoding.pl
@@ -172,9 +172,10 @@ is($node_primary->slot('otherdb_slot')->{'slot_name'},
undef, 'logical slot was actually dropped with DB');
# Test logical slot advancing and its durability.
+# Pass failover=true (last-arg), it should not have any impact on advancing.
my $logical_slot = 'logical_slot';
$node_primary->safe_psql('postgres',
- "SELECT pg_create_logical_replication_slot('$logical_slot', 'test_decoding', false);"
+ "SELECT pg_create_logical_replication_slot('$logical_slot', 'test_decoding', false, false, true);"
);
$node_primary->psql(
'postgres', "
diff --git a/src/test/recovery/t/050_standby_failover_slots_sync.pl b/src/test/recovery/t/050_standby_failover_slots_sync.pl
index 1055573cde..06a4ada941 100644
--- a/src/test/recovery/t/050_standby_failover_slots_sync.pl
+++ b/src/test/recovery/t/050_standby_failover_slots_sync.pl
@@ -87,17 +87,30 @@ is( $publisher->safe_psql(
$subscriber1->safe_psql('postgres', "ALTER SUBSCRIPTION regress_mysub1 ENABLE");
##################################################
-# Test logical failover slots on the standby
-# Configure standby1 to replicate and synchronize logical slots configured
-# for failover on the primary
+# Test primary disallowing specified logical replication slots getting ahead of
+# specified physical replication slots. It uses the following set up:
#
-# failover slot lsub1_slot->| ----> subscriber1 (connected via logical replication)
-# primary ---> |
-# physical slot sb1_slot--->| ----> standby1 (connected via streaming replication)
-# | lsub1_slot(synced_slot)
+# | ----> standby1 (primary_slot_name = sb1_slot)
+# | ----> standby2 (primary_slot_name = sb2_slot)
+# primary ----- |
+# | ----> subscriber1 (failover = true)
+# | ----> subscriber2 (failover = false)
+#
+# standby_slot_names = 'sb1_slot'
+#
+# Set up is configured in such a way that the logical slot of subscriber1 is
+# enabled failover, thus it will wait for the physical slot of
+# standby1(sb1_slot) to catch up before sending decoded changes to subscriber1.
##################################################
+# Create primary
my $primary = $publisher;
+
+$primary->psql('postgres',
+ q{SELECT pg_create_physical_replication_slot('sb1_slot');});
+$primary->psql('postgres',
+ q{SELECT pg_create_physical_replication_slot('sb2_slot');});
+
my $backup_name = 'backup';
$primary->backup($backup_name);
@@ -107,21 +120,201 @@ $standby1->init_from_backup(
$primary, $backup_name,
has_streaming => 1,
has_restoring => 1);
+$standby1->append_conf(
+ 'postgresql.conf', qq(
+primary_slot_name = 'sb1_slot'
+));
+$standby1->start;
+$primary->wait_for_replay_catchup($standby1);
+
+# Create another standby
+my $standby2 = PostgreSQL::Test::Cluster->new('standby2');
+$standby2->init_from_backup(
+ $primary, $backup_name,
+ has_streaming => 1,
+ has_restoring => 1);
+$standby2->append_conf(
+ 'postgresql.conf', qq(
+primary_slot_name = 'sb2_slot'
+));
+$standby2->start;
+$primary->wait_for_replay_catchup($standby2);
+
+# Configure primary to disallow any logical slots that enabled failover from
+# getting ahead of specified physical replication slot (sb1_slot).
+$primary->append_conf(
+ 'postgresql.conf', qq(
+standby_slot_names = 'sb1_slot'
+));
+$primary->reload;
+
+$primary->safe_psql('postgres', "CREATE TABLE tab_int (a int PRIMARY KEY);");
+
+# Create a table and refresh the publication
+$subscriber1->safe_psql(
+ 'postgres', qq[
+ CREATE TABLE tab_int (a int PRIMARY KEY);
+ ALTER SUBSCRIPTION regress_mysub1 REFRESH PUBLICATION WITH (copy_data = false);
+]);
+
+# Create another subscriber node without enabling failover, wait for sync to
+# complete
+my $subscriber2 = PostgreSQL::Test::Cluster->new('subscriber2');
+$subscriber2->init;
+$subscriber2->start;
+$subscriber2->safe_psql(
+ 'postgres', qq[
+ CREATE TABLE tab_int (a int PRIMARY KEY);
+ CREATE SUBSCRIPTION regress_mysub2 CONNECTION '$publisher_connstr' PUBLICATION regress_mypub WITH (slot_name = lsub2_slot, copy_data = false);
+]);
+# Stop the standby associated with the specified physical replication slot so
+# that the logical replication slot won't receive changes until the standby
+# comes up.
+$standby1->stop;
+
+# Create some data on the primary
+my $primary_row_count = 10;
+$primary->safe_psql('postgres',
+ "INSERT INTO tab_int SELECT generate_series(1, $primary_row_count);");
+
+# Wait for the standby that's up and running gets the data from primary
+$primary->wait_for_replay_catchup($standby2);
+my $result = $standby2->safe_psql('postgres',
+ "SELECT count(*) = $primary_row_count FROM tab_int;");
+is($result, 't', "standby2 gets data from primary");
+
+# Wait for the subscription that's up and running and is not enabled for failover.
+# It gets the data from primary without waiting for any standbys.
+$publisher->wait_for_catchup('regress_mysub2');
+$result = $subscriber2->safe_psql('postgres',
+ "SELECT count(*) = $primary_row_count FROM tab_int;");
+is($result, 't', "subscriber2 gets data from primary");
+
+# The subscription that's up and running and is enabled for failover
+# doesn't get the data from primary and keeps waiting for the
+# standby specified in standby_slot_names.
+$result =
+ $subscriber1->safe_psql('postgres', "SELECT count(*) = 0 FROM tab_int;");
+is($result, 't',
+ "subscriber1 doesn't get data from primary until standby1 acknowledges changes"
+);
+
+# Start the standby specified in standby_slot_names and wait for it to catch
+# up with the primary.
+$standby1->start;
+$primary->wait_for_replay_catchup($standby1);
+$result = $standby1->safe_psql('postgres',
+ "SELECT count(*) = $primary_row_count FROM tab_int;");
+is($result, 't', "standby1 gets data from primary");
+
+# Now that the standby specified in standby_slot_names is up and running,
+# primary must send the decoded changes to subscription enabled for failover
+# While the standby was down, this subscriber didn't receive any data from
+# primary i.e. the primary didn't allow it to go ahead of standby.
+$publisher->wait_for_catchup('regress_mysub1');
+$result = $subscriber1->safe_psql('postgres',
+ "SELECT count(*) = $primary_row_count FROM tab_int;");
+is($result, 't',
+ "subscriber1 gets data from primary after standby1 acknowledges changes");
+
+# Stop the standby associated with the specified physical replication slot so
+# that the logical replication slot won't receive changes until the standby
+# slot's restart_lsn is advanced or the slot is removed from the
+# standby_slot_names list.
+$publisher->safe_psql('postgres', "TRUNCATE tab_int;");
+$publisher->wait_for_catchup('regress_mysub1');
+$standby1->stop;
+
+##################################################
+# Verify that when using pg_logical_slot_get_changes to consume changes from a
+# logical slot with failover enabled, it will also wait for the slots specified
+# in standby_slot_names to catch up.
+##################################################
+
+# Create a logical 'test_decoding' replication slot with failover enabled
+$publisher->safe_psql('postgres',
+ "SELECT pg_create_logical_replication_slot('test_slot', 'test_decoding', false, false, true);"
+);
+
+my $back_q = $primary->background_psql('postgres', on_error_stop => 0);
+my $pid = $back_q->query('SELECT pg_backend_pid()');
+
+# Try and get changes from the logical slot with failover enabled.
+my $offset = -s $primary->logfile;
+$back_q->query_until(qr//,
+ "SELECT pg_logical_slot_get_changes('test_slot', NULL, NULL);\n");
+
+# Wait until the primary server logs a warning indicating that it is waiting
+# for the sb1_slot to catch up.
+$primary->wait_for_log(
+ qr/WARNING: ( [A-Z0-9]+:)? replication slot \"sb1_slot\" specified in parameter \"standby_slot_names\" does not have active_pid/,
+ $offset);
+
+ok($primary->safe_psql('postgres', "SELECT pg_cancel_backend($pid)"),
+ "cancelling pg_logical_slot_get_changes command");
+
+$back_q->quit;
+
+$publisher->safe_psql('postgres',
+ "SELECT pg_drop_replication_slot('test_slot');"
+);
+
+##################################################
+# Test that logical replication will wait for the user-created inactive
+# physical slot to catch up until we remove the slot from standby_slot_names.
+##################################################
+
+# Create some data on the primary
+$primary_row_count = 10;
+$primary->safe_psql('postgres',
+ "INSERT INTO tab_int SELECT generate_series(1, $primary_row_count);");
+
+$result =
+ $subscriber1->safe_psql('postgres', "SELECT count(*) = 0 FROM tab_int;");
+is($result, 't',
+ "subscriber1 doesn't get data as the sb1_slot doesn't catch up");
+
+# Remove the standby from the standby_slot_names list and reload the
+# configuration.
+$primary->adjust_conf('postgresql.conf', 'standby_slot_names', "''");
+$primary->reload;
+
+# Since there are no slots in standby_slot_names, the primary server should now
+# send the decoded changes to the subscription.
+$publisher->wait_for_catchup('regress_mysub1');
+$result = $subscriber1->safe_psql('postgres',
+ "SELECT count(*) = $primary_row_count FROM tab_int;");
+is($result, 't',
+ "subscriber1 gets data from primary after standby1 is removed from the standby_slot_names list"
+);
+
+# Put the standby back on the primary_slot_name for the rest of the tests
+$primary->adjust_conf('postgresql.conf', 'standby_slot_names', 'sb1_slot');
+$primary->reload;
+
+##################################################
+# Test logical failover slots on the standby
+# Configure standby1 to replicate and synchronize logical slots configured
+# for failover on the primary
+#
+# failover slot lsub1_slot->| ----> subscriber1 (connected via logical replication)
+# primary ---> |
+# physical slot sb1_slot--->| ----> standby1 (connected via streaming replication)
+# | lsub1_slot(synced_slot)
+##################################################
+
+# Create a standby
my $connstr_1 = $primary->connstr;
$standby1->append_conf(
'postgresql.conf', qq(
enable_syncslot = true
hot_standby_feedback = on
-primary_slot_name = 'sb1_slot'
primary_conninfo = '$connstr_1 dbname=postgres'
));
-$primary->psql('postgres',
- q{SELECT pg_create_physical_replication_slot('sb1_slot');});
-
my $standby1_conninfo = $standby1->connstr . ' dbname=postgres';
-my $offset = -s $standby1->logfile;
+$offset = -s $standby1->logfile;
# Start the standby so that slot syncing can begin
$standby1->start;
@@ -150,18 +343,11 @@ is($standby1->safe_psql('postgres',
# Insert data on the primary
$primary->safe_psql(
'postgres', qq[
- CREATE TABLE tab_int (a int PRIMARY KEY);
+ TRUNCATE TABLE tab_int;
INSERT INTO tab_int SELECT generate_series(1, 10);
]);
-# Subscribe to the new table data and wait for it to arrive
-$subscriber1->safe_psql(
- 'postgres', qq[
- CREATE TABLE tab_int (a int PRIMARY KEY);
- ALTER SUBSCRIPTION regress_mysub1 REFRESH PUBLICATION;
-]);
-
-$subscriber1->wait_for_subscription_sync;
+$primary->wait_for_catchup('regress_mysub1');
# Do not allow any further advancement of the restart_lsn and
# confirmed_flush_lsn for the lsub1_slot.
@@ -199,7 +385,9 @@ $standby1->safe_psql('postgres', 'ALTER SYSTEM SET hot_standby_feedback = off;')
$standby1->restart;
# Attempting to perform logical decoding on a synced slot should result in an error
-my ($result, $stdout, $stderr) = $standby1->psql('postgres',
+my ($stdout, $stderr);
+
+($result, $stdout, $stderr) = $standby1->psql('postgres',
"select * from pg_logical_slot_get_changes('lsub1_slot',NULL,NULL);");
ok($stderr =~ /ERROR: cannot use replication slot "lsub1_slot" for logical decoding/,
"logical decoding is not allowed on synced slot");
--
2.30.0.windows.2
[application/octet-stream] v68-0007-Non-replication-connection-and-app_name-change.patch (9.7K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/4-v68-0007-Non-replication-connection-and-app_name-change.patch)
download | inline diff:
From 093630966d073c3c141e275cd52e9f55afbc7bfb Mon Sep 17 00:00:00 2001
From: Shveta Malik <[email protected]>
Date: Tue, 23 Jan 2024 15:48:53 +0530
Subject: [PATCH v68 7/8] Non replication connection and app_name change.
This patch has converted replication connection to non-replication
one in the slotsync worker.
It has also changed the app_name to {cluster_name}_slotsyncworker
in the slotsync worker connection.
---
src/backend/commands/subscriptioncmds.c | 12 +++--
.../libpqwalreceiver/libpqwalreceiver.c | 44 +++++++++++++------
src/backend/replication/logical/slotsync.c | 14 +++++-
src/backend/replication/logical/tablesync.c | 2 +-
src/backend/replication/logical/worker.c | 4 +-
src/backend/replication/walreceiver.c | 3 +-
src/include/replication/walreceiver.h | 5 ++-
7 files changed, 60 insertions(+), 24 deletions(-)
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 15bb10da54..f17c666ebc 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -753,7 +753,8 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
/* Try to connect to the publisher. */
must_use_password = !superuser_arg(owner) && opts.passwordrequired;
- wrconn = walrcv_connect(conninfo, true, must_use_password,
+ wrconn = walrcv_connect(conninfo, true /* replication */ ,
+ true, must_use_password,
stmt->subname, &err);
if (!wrconn)
ereport(ERROR,
@@ -904,7 +905,8 @@ AlterSubscription_refresh(Subscription *sub, bool copy_data,
/* Try to connect to the publisher. */
must_use_password = sub->passwordrequired && !sub->ownersuperuser;
- wrconn = walrcv_connect(sub->conninfo, true, must_use_password,
+ wrconn = walrcv_connect(sub->conninfo, true /* replication */ ,
+ true, must_use_password,
sub->name, &err);
if (!wrconn)
ereport(ERROR,
@@ -1531,7 +1533,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
/* Try to connect to the publisher. */
must_use_password = sub->passwordrequired && !sub->ownersuperuser;
- wrconn = walrcv_connect(sub->conninfo, true, must_use_password,
+ wrconn = walrcv_connect(sub->conninfo, true /* replication */ ,
+ true, must_use_password,
sub->name, &err);
if (!wrconn)
ereport(ERROR,
@@ -1782,7 +1785,8 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
*/
load_file("libpqwalreceiver", false);
- wrconn = walrcv_connect(conninfo, true, must_use_password,
+ wrconn = walrcv_connect(conninfo, true /* replication */ ,
+ true, must_use_password,
subname, &err);
if (wrconn == NULL)
{
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index ae76c098b1..13a787b8bf 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -6,6 +6,9 @@
* loaded as a dynamic module to avoid linking the main server binary with
* libpq.
*
+ * Apart from walreceiver, the libpq-specific routines here are now being used
+ * by logical replication workers and slotsync worker as well.
+
* Portions Copyright (c) 2010-2024, PostgreSQL Global Development Group
*
*
@@ -49,7 +52,8 @@ struct WalReceiverConn
/* Prototypes for interface functions */
static WalReceiverConn *libpqrcv_connect(const char *conninfo,
- bool logical, bool must_use_password,
+ bool replication, bool logical,
+ bool must_use_password,
const char *appname, char **err);
static void libpqrcv_check_conninfo(const char *conninfo,
bool must_use_password);
@@ -124,7 +128,12 @@ _PG_init(void)
}
/*
- * Establish the connection to the primary server for XLOG streaming
+ * Establish the connection to the primary server.
+ *
+ * The connection established could be either a replication one or
+ * a non-replication one based on input argument 'replication'. And further
+ * if it is a replication connection, it could be either logical or physical
+ * based on input argument 'logical'.
*
* If an error occurs, this function will normally return NULL and set *err
* to a palloc'ed error message. However, if must_use_password is true and
@@ -135,8 +144,8 @@ _PG_init(void)
* case.
*/
static WalReceiverConn *
-libpqrcv_connect(const char *conninfo, bool logical, bool must_use_password,
- const char *appname, char **err)
+libpqrcv_connect(const char *conninfo, bool replication, bool logical,
+ bool must_use_password, const char *appname, char **err)
{
WalReceiverConn *conn;
PostgresPollingStatusType status;
@@ -159,17 +168,26 @@ libpqrcv_connect(const char *conninfo, bool logical, bool must_use_password,
*/
keys[i] = "dbname";
vals[i] = conninfo;
- keys[++i] = "replication";
- vals[i] = logical ? "database" : "true";
- if (!logical)
+
+ /* We can not have logical without replication */
+ if (!replication)
+ Assert(!logical);
+ else
{
- /*
- * The database name is ignored by the server in replication mode, but
- * specify "replication" for .pgpass lookup.
- */
- keys[++i] = "dbname";
- vals[i] = "replication";
+ keys[++i] = "replication";
+ vals[i] = logical ? "database" : "true";
+
+ if (!logical)
+ {
+ /*
+ * The database name is ignored by the server in replication mode,
+ * but specify "replication" for .pgpass lookup.
+ */
+ keys[++i] = "dbname";
+ vals[i] = "replication";
+ }
}
+
keys[++i] = "fallback_application_name";
vals[i] = appname;
if (logical)
diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c
index 2a033647b3..39d66b3ed0 100644
--- a/src/backend/replication/logical/slotsync.c
+++ b/src/backend/replication/logical/slotsync.c
@@ -1067,6 +1067,7 @@ ReplSlotSyncWorkerMain(int argc, char *argv[])
bool primary_slot_invalid;
char *err;
sigjmp_buf local_sigjmp_buf;
+ StringInfoData app_name;
am_slotsync_worker = true;
@@ -1176,13 +1177,22 @@ ReplSlotSyncWorkerMain(int argc, char *argv[])
SetProcessingMode(NormalProcessing);
+ initStringInfo(&app_name);
+ if (cluster_name[0])
+ appendStringInfo(&app_name, "%s_%s", cluster_name, "slotsyncworker");
+ else
+ appendStringInfo(&app_name, "%s", "slotsyncworker");
+
/*
* Establish the connection to the primary server for slots
* synchronization.
*/
- wrconn = walrcv_connect(PrimaryConnInfo, true, false,
- cluster_name[0] ? cluster_name : "slotsyncworker",
+ wrconn = walrcv_connect(PrimaryConnInfo, false /* replication */,
+ false, false,
+ app_name.data,
&err);
+ pfree(app_name.data);
+
if (!wrconn)
ereport(ERROR,
errcode(ERRCODE_CONNECTION_FAILURE),
diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 5acab3f3e2..c5c6ac4bac 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -1329,7 +1329,7 @@ LogicalRepSyncTableStart(XLogRecPtr *origin_startpos)
* so that synchronous replication can distinguish them.
*/
LogRepWorkerWalRcvConn =
- walrcv_connect(MySubscription->conninfo, true,
+ walrcv_connect(MySubscription->conninfo, true /* replication */ , true,
must_use_password,
slotname, &err);
if (LogRepWorkerWalRcvConn == NULL)
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 32ff4c0336..0d791c188c 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -4518,7 +4518,9 @@ run_apply_worker()
must_use_password = MySubscription->passwordrequired &&
!MySubscription->ownersuperuser;
- LogRepWorkerWalRcvConn = walrcv_connect(MySubscription->conninfo, true,
+ LogRepWorkerWalRcvConn = walrcv_connect(MySubscription->conninfo,
+ true /* replication */ ,
+ true,
must_use_password,
MySubscription->name, &err);
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index e29a6196a3..872cccb54b 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -296,7 +296,8 @@ WalReceiverMain(void)
sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
/* Establish the connection to the primary for XLOG streaming */
- wrconn = walrcv_connect(conninfo, false, false,
+ wrconn = walrcv_connect(conninfo, true /* replication */ ,
+ false, false,
cluster_name[0] ? cluster_name : "walreceiver",
&err);
if (!wrconn)
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 48dc846e19..1b563a16cd 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -237,6 +237,7 @@ typedef struct WalRcvExecResult
* returned with 'err' including the error generated.
*/
typedef WalReceiverConn *(*walrcv_connect_fn) (const char *conninfo,
+ bool replication,
bool logical,
bool must_use_password,
const char *appname,
@@ -426,8 +427,8 @@ typedef struct WalReceiverFunctionsType
extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
-#define walrcv_connect(conninfo, logical, must_use_password, appname, err) \
- WalReceiverFunctions->walrcv_connect(conninfo, logical, must_use_password, appname, err)
+#define walrcv_connect(conninfo, replication, logical, must_use_password, appname, err) \
+ WalReceiverFunctions->walrcv_connect(conninfo, replication, logical, must_use_password, appname, err)
#define walrcv_check_conninfo(conninfo, must_use_password) \
WalReceiverFunctions->walrcv_check_conninfo(conninfo, must_use_password)
#define walrcv_get_conninfo(conn) \
--
2.30.0.windows.2
[application/octet-stream] v68-0008-Document-the-steps-to-check-if-the-standby-is-re.patch (6.6K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/5-v68-0008-Document-the-steps-to-check-if-the-standby-is-re.patch)
download | inline diff:
From 7670b16d5c3a6f9c22284c4f90be3089308345c8 Mon Sep 17 00:00:00 2001
From: Shveta Malik <[email protected]>
Date: Fri, 19 Jan 2024 11:04:16 +0530
Subject: [PATCH v68 8/8] Document the steps to check if the standby is ready
for failover
---
doc/src/sgml/high-availability.sgml | 9 ++
doc/src/sgml/logical-replication.sgml | 130 ++++++++++++++++++++++++++
2 files changed, 139 insertions(+)
diff --git a/doc/src/sgml/high-availability.sgml b/doc/src/sgml/high-availability.sgml
index 236c0af65f..36215aa68c 100644
--- a/doc/src/sgml/high-availability.sgml
+++ b/doc/src/sgml/high-availability.sgml
@@ -1487,6 +1487,15 @@ synchronous_standby_names = 'ANY 2 (s1, s2, s3)'
Written administration procedures are advised.
</para>
+ <para>
+ If you have opted for synchronization of logical slots (see
+ <xref linkend="logicaldecoding-replication-slots-synchronization"/>),
+ then before switching to the standby server, it is recommended to check
+ if the logical slots synchronized on the standby server are ready
+ for failover. This can be done by following the steps described in
+ <xref linkend="logical-replication-failover"/>.
+ </para>
+
<para>
To trigger failover of a log-shipping standby server, run
<command>pg_ctl promote</command> or call <function>pg_promote()</function>.
diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml
index ec2130669e..924e4ea033 100644
--- a/doc/src/sgml/logical-replication.sgml
+++ b/doc/src/sgml/logical-replication.sgml
@@ -687,6 +687,136 @@ ALTER SUBSCRIPTION
</sect1>
+ <sect1 id="logical-replication-failover">
+ <title>Logical Replication Failover</title>
+
+ <para>
+ When the publisher server is the primary server of a streaming replication,
+ the logical slots on that primary server can be synchronized to the standby
+ server by specifying <literal>failover = true</literal> when creating
+ subscriptions for those publications. Enabling failover ensures a seamless
+ transition of those subscriptions after the standby is promoted. They can
+ continue subscribing to publications now on the new primary server without
+ any data loss.
+ </para>
+
+ <para>
+ Because the slot synchronization logic copies asynchronously, it is
+ necessary to confirm that replication slots have been synced to the standby
+ server before the failover happens. Furthermore, to ensure a successful
+ failover, the standby server must not be lagging behind the subscriber. It
+ is highly recommended to use
+ <link linkend="guc-standby-slot-names"><varname>standby_slot_names</varname></link>
+ to prevent the subscriber from consuming changes faster than the hot standby.
+ To confirm that the standby server is indeed ready for failover, follow
+ these 2 steps:
+ </para>
+
+ <procedure>
+ <step performance="required">
+ <para>
+ Confirm that all the necessary logical replication slots have been synced to
+ the standby server.
+ </para>
+ <substeps>
+ <step performance="required">
+ <para>
+ Firstly, on the subscriber node, use the following SQL to identify
+ which slots should be synced to the standby that we plan to promote.
+<programlisting>
+test_sub=# SELECT
+ array_agg(slotname) AS slots
+ FROM
+ ((
+ SELECT r.srsubid AS subid, CONCAT('pg_' || srsubid || '_sync_' || srrelid || '_' || ctl.system_identifier) AS slotname
+ FROM pg_control_system() ctl, pg_subscription_rel r, pg_subscription s
+ WHERE r.srsubstate = 'f' AND s.oid = r.srsubid AND s.subfailover
+ ) UNION (
+ SELECT s.oid AS subid, s.subslotname as slotname
+ FROM pg_subscription s
+ WHERE s.subfailover
+ ));
+ slots
+-------
+ {sub1,sub2,sub3}
+(1 row)
+</programlisting></para>
+ </step>
+ <step performance="required">
+ <para>
+ Next, check that the logical replication slots identified above exist on
+ the standby server and are ready for failover.
+<programlisting>
+test_standby=# SELECT slot_name, (synced AND NOT temporary AND conflict_reason IS NULL) AS failover_ready
+ FROM pg_replication_slots
+ WHERE slot_name IN ('sub1','sub2','sub3');
+ slot_name | failover_ready
+-------------+----------------
+ sub1 | t
+ sub2 | t
+ sub3 | t
+(3 rows)
+</programlisting></para>
+ </step>
+ </substeps>
+ </step>
+
+ <step performance="required">
+ <para>
+ Confirm that the standby server is not lagging behind the subscribers.
+ This step can be skipped if
+ <link linkend="guc-standby-slot-names"><varname>standby_slot_names</varname></link>
+ has been correctly configured.
+ </para>
+ <substeps>
+ <step performance="required">
+ <para>
+ Firstly, on the subscriber node check the last replayed WAL.
+<programlisting>
+test_sub=# SELECT
+ MAX(remote_lsn) AS remote_lsn_on_subscriber
+ FROM
+ ((
+ SELECT (CASE WHEN r.srsubstate = 'f' THEN pg_replication_origin_progress(CONCAT('pg_' || r.srsubid || '_' || r.srrelid), false)
+ WHEN r.srsubstate IN ('s', 'r') THEN r.srsublsn END) AS remote_lsn
+ FROM pg_subscription_rel r, pg_subscription s
+ WHERE r.srsubstate IN ('f', 's', 'r') AND s.oid = r.srsubid AND s.subfailover
+ ) UNION (
+ SELECT pg_replication_origin_progress(CONCAT('pg_' || s.oid), false) AS remote_lsn
+ FROM pg_subscription s
+ WHERE s.subfailover
+ ));
+ remote_lsn_on_subscriber
+--------------------------
+ 0/3000388
+</programlisting></para>
+ </step>
+ <step performance="required">
+ <para>
+ Next, on the standby server check that the last-received WAL location
+ is ahead of the replayed WAL location on the subscriber identified above.
+ If the above SQL result was NULL, it means the subscriber has not yet
+ replayed any WAL, so the standby server must be ahead of the
+ subscriber, and this step can be skipped.
+<programlisting>
+test_standby=# SELECT pg_last_wal_receive_lsn() >= '0/3000388'::pg_lsn AS failover_ready;
+ failover_ready
+----------------
+ t
+(1 row)
+</programlisting></para>
+ </step>
+ </substeps>
+ </step>
+ </procedure>
+
+ <para>
+ If the result (<literal>failover_ready</literal>) of both above steps is
+ true, existing subscriptions will be able to continue without data loss.
+ </para>
+
+ </sect1>
+
<sect1 id="logical-replication-row-filter">
<title>Row Filters</title>
--
2.30.0.windows.2
[application/octet-stream] v68-0001-Add-the-failover-property-to-replication-slot.patch (20.4K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/6-v68-0001-Add-the-failover-property-to-replication-slot.patch)
download | inline diff:
From 60a8101d03fe5780402b563f166ace619ddad374 Mon Sep 17 00:00:00 2001
From: Hou Zhijie <[email protected]>
Date: Wed, 24 Jan 2024 20:14:52 +0800
Subject: [PATCH v68 1/8] Add the failover property to replication slot.
This commit adds the failover property to the replication slot. The
failover property indicates whether the slot will be synced to the standby
servers, enabling the resumption of corresponding logical replication
after failover. But note that this commit does not yet include the
capability to actually sync the replication slot; the subsequent commit will
address that.
In addition, a new parameter 'failover' is added to the
pg_create_logical_replication_slot function.
The value of the 'failover' flag is displayed as part of
pg_replication_slots view.
---
contrib/test_decoding/expected/slot.out | 58 ++++++++++++++++++++++++
contrib/test_decoding/sql/slot.sql | 13 ++++++
doc/src/sgml/func.sgml | 11 +++--
doc/src/sgml/system-views.sgml | 11 +++++
src/backend/catalog/system_functions.sql | 1 +
src/backend/catalog/system_views.sql | 3 +-
src/backend/replication/slot.c | 8 +++-
src/backend/replication/slotfuncs.c | 16 +++++--
src/backend/replication/walsender.c | 4 +-
src/bin/pg_upgrade/info.c | 5 +-
src/bin/pg_upgrade/pg_upgrade.c | 6 ++-
src/bin/pg_upgrade/pg_upgrade.h | 2 +
src/include/catalog/pg_proc.dat | 14 +++---
src/include/replication/slot.h | 8 +++-
src/test/regress/expected/rules.out | 5 +-
15 files changed, 141 insertions(+), 24 deletions(-)
diff --git a/contrib/test_decoding/expected/slot.out b/contrib/test_decoding/expected/slot.out
index 63a9940f73..261d8886d3 100644
--- a/contrib/test_decoding/expected/slot.out
+++ b/contrib/test_decoding/expected/slot.out
@@ -406,3 +406,61 @@ SELECT pg_drop_replication_slot('copied_slot2_notemp');
(1 row)
+-- Test failover option of slots.
+SELECT 'init' FROM pg_create_logical_replication_slot('failover_true_slot', 'test_decoding', false, false, true);
+ ?column?
+----------
+ init
+(1 row)
+
+SELECT 'init' FROM pg_create_logical_replication_slot('failover_false_slot', 'test_decoding', false, false, false);
+ ?column?
+----------
+ init
+(1 row)
+
+SELECT 'init' FROM pg_create_logical_replication_slot('failover_default_slot', 'test_decoding', false, false);
+ ?column?
+----------
+ init
+(1 row)
+
+SELECT 'init' FROM pg_create_physical_replication_slot('physical_slot');
+ ?column?
+----------
+ init
+(1 row)
+
+SELECT slot_name, slot_type, failover FROM pg_replication_slots;
+ slot_name | slot_type | failover
+-----------------------+-----------+----------
+ failover_true_slot | logical | t
+ failover_false_slot | logical | f
+ failover_default_slot | logical | f
+ physical_slot | physical | f
+(4 rows)
+
+SELECT pg_drop_replication_slot('failover_true_slot');
+ pg_drop_replication_slot
+--------------------------
+
+(1 row)
+
+SELECT pg_drop_replication_slot('failover_false_slot');
+ pg_drop_replication_slot
+--------------------------
+
+(1 row)
+
+SELECT pg_drop_replication_slot('failover_default_slot');
+ pg_drop_replication_slot
+--------------------------
+
+(1 row)
+
+SELECT pg_drop_replication_slot('physical_slot');
+ pg_drop_replication_slot
+--------------------------
+
+(1 row)
+
diff --git a/contrib/test_decoding/sql/slot.sql b/contrib/test_decoding/sql/slot.sql
index 1aa27c5667..45aeae7fd5 100644
--- a/contrib/test_decoding/sql/slot.sql
+++ b/contrib/test_decoding/sql/slot.sql
@@ -176,3 +176,16 @@ ORDER BY o.slot_name, c.slot_name;
SELECT pg_drop_replication_slot('orig_slot2');
SELECT pg_drop_replication_slot('copied_slot2_no_change');
SELECT pg_drop_replication_slot('copied_slot2_notemp');
+
+-- Test failover option of slots.
+SELECT 'init' FROM pg_create_logical_replication_slot('failover_true_slot', 'test_decoding', false, false, true);
+SELECT 'init' FROM pg_create_logical_replication_slot('failover_false_slot', 'test_decoding', false, false, false);
+SELECT 'init' FROM pg_create_logical_replication_slot('failover_default_slot', 'test_decoding', false, false);
+SELECT 'init' FROM pg_create_physical_replication_slot('physical_slot');
+
+SELECT slot_name, slot_type, failover FROM pg_replication_slots;
+
+SELECT pg_drop_replication_slot('failover_true_slot');
+SELECT pg_drop_replication_slot('failover_false_slot');
+SELECT pg_drop_replication_slot('failover_default_slot');
+SELECT pg_drop_replication_slot('physical_slot');
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 210c7c0b02..0ee76835bc 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -27655,7 +27655,7 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
<indexterm>
<primary>pg_create_logical_replication_slot</primary>
</indexterm>
- <function>pg_create_logical_replication_slot</function> ( <parameter>slot_name</parameter> <type>name</type>, <parameter>plugin</parameter> <type>name</type> <optional>, <parameter>temporary</parameter> <type>boolean</type>, <parameter>twophase</parameter> <type>boolean</type> </optional> )
+ <function>pg_create_logical_replication_slot</function> ( <parameter>slot_name</parameter> <type>name</type>, <parameter>plugin</parameter> <type>name</type> <optional>, <parameter>temporary</parameter> <type>boolean</type>, <parameter>twophase</parameter> <type>boolean</type>, <parameter>failover</parameter> <type>boolean</type> </optional> )
<returnvalue>record</returnvalue>
( <parameter>slot_name</parameter> <type>name</type>,
<parameter>lsn</parameter> <type>pg_lsn</type> )
@@ -27670,8 +27670,13 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
released upon any error. The optional fourth parameter,
<parameter>twophase</parameter>, when set to true, specifies
that the decoding of prepared transactions is enabled for this
- slot. A call to this function has the same effect as the replication
- protocol command <literal>CREATE_REPLICATION_SLOT ... LOGICAL</literal>.
+ slot. The optional fifth parameter,
+ <parameter>failover</parameter>, when set to true,
+ specifies that this slot is enabled to be synced to the
+ standbys so that logical replication can be resumed after
+ failover. A call to this function has the same effect as
+ the replication protocol command
+ <literal>CREATE_REPLICATION_SLOT ... LOGICAL</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml
index 72d01fc624..88fe4b6341 100644
--- a/doc/src/sgml/system-views.sgml
+++ b/doc/src/sgml/system-views.sgml
@@ -2555,6 +2555,17 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
</itemizedlist>
</para></entry>
</row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>failover</structfield> <type>bool</type>
+ </para>
+ <para>
+ True if this is a logical slot enabled to be synced to the standbys
+ so that logical replication can be resumed from the new primary
+ after failover. Always false for physical slots.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index f315fecf18..346cfb98a0 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -479,6 +479,7 @@ CREATE OR REPLACE FUNCTION pg_create_logical_replication_slot(
IN slot_name name, IN plugin name,
IN temporary boolean DEFAULT false,
IN twophase boolean DEFAULT false,
+ IN failover boolean DEFAULT false,
OUT slot_name name, OUT lsn pg_lsn)
RETURNS RECORD
LANGUAGE INTERNAL
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index e43e36f5ac..d0f711a619 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1023,7 +1023,8 @@ CREATE VIEW pg_replication_slots AS
L.wal_status,
L.safe_wal_size,
L.two_phase,
- L.conflict_reason
+ L.conflict_reason,
+ L.failover
FROM pg_get_replication_slots() AS L
LEFT JOIN pg_database D ON (L.datoid = D.oid);
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 52da694c79..02a14ec210 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -90,7 +90,7 @@ typedef struct ReplicationSlotOnDisk
sizeof(ReplicationSlotOnDisk) - ReplicationSlotOnDiskConstantSize
#define SLOT_MAGIC 0x1051CA1 /* format identifier */
-#define SLOT_VERSION 3 /* version for new files */
+#define SLOT_VERSION 4 /* version for new files */
/* Control array for replication slot management */
ReplicationSlotCtlData *ReplicationSlotCtl = NULL;
@@ -248,10 +248,13 @@ ReplicationSlotValidateName(const char *name, int elevel)
* during getting changes, if the two_phase option is enabled it can skip
* prepare because by that time start decoding point has been moved. So the
* user will only get commit prepared.
+ * failover: If enabled, allows the slot to be synced to standbys so
+ * that logical replication can be resumed after failover.
*/
void
ReplicationSlotCreate(const char *name, bool db_specific,
- ReplicationSlotPersistency persistency, bool two_phase)
+ ReplicationSlotPersistency persistency,
+ bool two_phase, bool failover)
{
ReplicationSlot *slot = NULL;
int i;
@@ -311,6 +314,7 @@ ReplicationSlotCreate(const char *name, bool db_specific,
slot->data.persistency = persistency;
slot->data.two_phase = two_phase;
slot->data.two_phase_at = InvalidXLogRecPtr;
+ slot->data.failover = failover;
/* and then data only present in shared memory */
slot->just_dirtied = false;
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index cad35dce7f..eb685089b3 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -42,7 +42,8 @@ create_physical_replication_slot(char *name, bool immediately_reserve,
/* acquire replication slot, this will check for conflicting names */
ReplicationSlotCreate(name, false,
- temporary ? RS_TEMPORARY : RS_PERSISTENT, false);
+ temporary ? RS_TEMPORARY : RS_PERSISTENT, false,
+ false);
if (immediately_reserve)
{
@@ -117,6 +118,7 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
static void
create_logical_replication_slot(char *name, char *plugin,
bool temporary, bool two_phase,
+ bool failover,
XLogRecPtr restart_lsn,
bool find_startpoint)
{
@@ -133,7 +135,8 @@ create_logical_replication_slot(char *name, char *plugin,
* error as well.
*/
ReplicationSlotCreate(name, true,
- temporary ? RS_TEMPORARY : RS_EPHEMERAL, two_phase);
+ temporary ? RS_TEMPORARY : RS_EPHEMERAL, two_phase,
+ failover);
/*
* Create logical decoding context to find start point or, if we don't
@@ -171,6 +174,7 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
Name plugin = PG_GETARG_NAME(1);
bool temporary = PG_GETARG_BOOL(2);
bool two_phase = PG_GETARG_BOOL(3);
+ bool failover = PG_GETARG_BOOL(4);
Datum result;
TupleDesc tupdesc;
HeapTuple tuple;
@@ -188,6 +192,7 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
NameStr(*plugin),
temporary,
two_phase,
+ failover,
InvalidXLogRecPtr,
true);
@@ -232,7 +237,7 @@ pg_drop_replication_slot(PG_FUNCTION_ARGS)
Datum
pg_get_replication_slots(PG_FUNCTION_ARGS)
{
-#define PG_GET_REPLICATION_SLOTS_COLS 15
+#define PG_GET_REPLICATION_SLOTS_COLS 16
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
XLogRecPtr currlsn;
int slotno;
@@ -426,6 +431,8 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
}
}
+ values[i++] = BoolGetDatum(slot_contents.data.failover);
+
Assert(i == PG_GET_REPLICATION_SLOTS_COLS);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
@@ -693,6 +700,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
XLogRecPtr src_restart_lsn;
bool src_islogical;
bool temporary;
+ bool failover;
char *plugin;
Datum values[2];
bool nulls[2];
@@ -748,6 +756,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
src_islogical = SlotIsLogical(&first_slot_contents);
src_restart_lsn = first_slot_contents.data.restart_lsn;
temporary = (first_slot_contents.data.persistency == RS_TEMPORARY);
+ failover = first_slot_contents.data.failover;
plugin = logical_slot ? NameStr(first_slot_contents.data.plugin) : NULL;
/* Check type of replication slot */
@@ -787,6 +796,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
plugin,
temporary,
false,
+ failover,
src_restart_lsn,
false);
}
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 087031e9dc..aa80f3de20 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1212,7 +1212,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
{
ReplicationSlotCreate(cmd->slotname, false,
cmd->temporary ? RS_TEMPORARY : RS_PERSISTENT,
- false);
+ false, false);
if (reserve_wal)
{
@@ -1243,7 +1243,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
*/
ReplicationSlotCreate(cmd->slotname, true,
cmd->temporary ? RS_TEMPORARY : RS_EPHEMERAL,
- two_phase);
+ two_phase, false);
/*
* Do options check early so that we can bail before calling the
diff --git a/src/bin/pg_upgrade/info.c b/src/bin/pg_upgrade/info.c
index 74e02b3f82..183c2f84eb 100644
--- a/src/bin/pg_upgrade/info.c
+++ b/src/bin/pg_upgrade/info.c
@@ -666,7 +666,7 @@ get_old_cluster_logical_slot_infos(DbInfo *dbinfo, bool live_check)
* started and stopped several times causing any temporary slots to be
* removed.
*/
- res = executeQueryOrDie(conn, "SELECT slot_name, plugin, two_phase, "
+ res = executeQueryOrDie(conn, "SELECT slot_name, plugin, two_phase, failover, "
"%s as caught_up, conflict_reason IS NOT NULL as invalid "
"FROM pg_catalog.pg_replication_slots "
"WHERE slot_type = 'logical' AND "
@@ -684,6 +684,7 @@ get_old_cluster_logical_slot_infos(DbInfo *dbinfo, bool live_check)
int i_slotname;
int i_plugin;
int i_twophase;
+ int i_failover;
int i_caught_up;
int i_invalid;
@@ -692,6 +693,7 @@ get_old_cluster_logical_slot_infos(DbInfo *dbinfo, bool live_check)
i_slotname = PQfnumber(res, "slot_name");
i_plugin = PQfnumber(res, "plugin");
i_twophase = PQfnumber(res, "two_phase");
+ i_failover = PQfnumber(res, "failover");
i_caught_up = PQfnumber(res, "caught_up");
i_invalid = PQfnumber(res, "invalid");
@@ -702,6 +704,7 @@ get_old_cluster_logical_slot_infos(DbInfo *dbinfo, bool live_check)
curr->slotname = pg_strdup(PQgetvalue(res, slotnum, i_slotname));
curr->plugin = pg_strdup(PQgetvalue(res, slotnum, i_plugin));
curr->two_phase = (strcmp(PQgetvalue(res, slotnum, i_twophase), "t") == 0);
+ curr->failover = (strcmp(PQgetvalue(res, slotnum, i_failover), "t") == 0);
curr->caught_up = (strcmp(PQgetvalue(res, slotnum, i_caught_up), "t") == 0);
curr->invalid = (strcmp(PQgetvalue(res, slotnum, i_invalid), "t") == 0);
}
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 14a36f0503..10c94a6c1f 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -916,8 +916,10 @@ create_logical_replication_slots(void)
appendStringLiteralConn(query, slot_info->slotname, conn);
appendPQExpBuffer(query, ", ");
appendStringLiteralConn(query, slot_info->plugin, conn);
- appendPQExpBuffer(query, ", false, %s);",
- slot_info->two_phase ? "true" : "false");
+
+ appendPQExpBuffer(query, ", false, %s, %s);",
+ slot_info->two_phase ? "true" : "false",
+ slot_info->failover ? "true" : "false");
PQclear(executeQueryOrDie(conn, "%s", query->data));
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index a1d08c3dab..d9a848cbfd 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -160,6 +160,8 @@ typedef struct
bool two_phase; /* can the slot decode 2PC? */
bool caught_up; /* has the slot caught up to latest changes? */
bool invalid; /* if true, the slot is unusable */
+ bool failover; /* is the slot designated to be synced to the
+ * physical standby? */
} LogicalSlotInfo;
typedef struct
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index ad74e07dbb..e6e4bbdfb9 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11123,17 +11123,17 @@
proname => 'pg_get_replication_slots', prorows => '10', proisstrict => 'f',
proretset => 't', provolatile => 's', prorettype => 'record',
proargtypes => '',
- proallargtypes => '{name,name,text,oid,bool,bool,int4,xid,xid,pg_lsn,pg_lsn,text,int8,bool,text}',
- proargmodes => '{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
- proargnames => '{slot_name,plugin,slot_type,datoid,temporary,active,active_pid,xmin,catalog_xmin,restart_lsn,confirmed_flush_lsn,wal_status,safe_wal_size,two_phase,conflict_reason}',
+ proallargtypes => '{name,name,text,oid,bool,bool,int4,xid,xid,pg_lsn,pg_lsn,text,int8,bool,text,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
+ proargnames => '{slot_name,plugin,slot_type,datoid,temporary,active,active_pid,xmin,catalog_xmin,restart_lsn,confirmed_flush_lsn,wal_status,safe_wal_size,two_phase,conflict_reason,failover}',
prosrc => 'pg_get_replication_slots' },
{ oid => '3786', descr => 'set up a logical replication slot',
proname => 'pg_create_logical_replication_slot', provolatile => 'v',
proparallel => 'u', prorettype => 'record',
- proargtypes => 'name name bool bool',
- proallargtypes => '{name,name,bool,bool,name,pg_lsn}',
- proargmodes => '{i,i,i,i,o,o}',
- proargnames => '{slot_name,plugin,temporary,twophase,slot_name,lsn}',
+ proargtypes => 'name name bool bool bool',
+ proallargtypes => '{name,name,bool,bool,bool,name,pg_lsn}',
+ proargmodes => '{i,i,i,i,i,o,o}',
+ proargnames => '{slot_name,plugin,temporary,twophase,failover,slot_name,lsn}',
prosrc => 'pg_create_logical_replication_slot' },
{ oid => '4222',
descr => 'copy a logical replication slot, changing temporality and plugin',
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 9e39aaf303..f2501be553 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -111,6 +111,12 @@ typedef struct ReplicationSlotPersistentData
/* plugin name */
NameData plugin;
+
+ /*
+ * Is this a failover slot (sync candidate for standbys)? Only
+ * relevant for logical slots on the primary server.
+ */
+ bool failover;
} ReplicationSlotPersistentData;
/*
@@ -218,7 +224,7 @@ extern void ReplicationSlotsShmemInit(void);
/* management of individual slots */
extern void ReplicationSlotCreate(const char *name, bool db_specific,
ReplicationSlotPersistency persistency,
- bool two_phase);
+ bool two_phase, bool failover);
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 55f2e95352..57884d3fec 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1473,8 +1473,9 @@ pg_replication_slots| SELECT l.slot_name,
l.wal_status,
l.safe_wal_size,
l.two_phase,
- l.conflict_reason
- FROM (pg_get_replication_slots() l(slot_name, plugin, slot_type, datoid, temporary, active, active_pid, xmin, catalog_xmin, restart_lsn, confirmed_flush_lsn, wal_status, safe_wal_size, two_phase, conflict_reason)
+ l.conflict_reason,
+ l.failover
+ FROM (pg_get_replication_slots() l(slot_name, plugin, slot_type, datoid, temporary, active, active_pid, xmin, catalog_xmin, restart_lsn, confirmed_flush_lsn, wal_status, safe_wal_size, two_phase, conflict_reason, failover)
LEFT JOIN pg_database d ON ((l.datoid = d.oid)));
pg_roles| SELECT pg_authid.rolname,
pg_authid.rolsuper,
--
2.30.0.windows.2
[application/octet-stream] v68-0002-Allow-setting-failover-property-in-the-replicati.patch (19.7K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/7-v68-0002-Allow-setting-failover-property-in-the-replicati.patch)
download | inline diff:
From 090be3ecaea83c59c919ef56b0fa587c4d19527c Mon Sep 17 00:00:00 2001
From: Hou Zhijie <[email protected]>
Date: Wed, 24 Jan 2024 20:04:18 +0800
Subject: [PATCH v68 2/8] Allow setting failover property in the replication
command.
This commit implements a new replication command called ALTER_REPLICATION_SLOT
and a corresponding walreceiver API function named walrcv_alter_slot.
Additionally, the CREATE_REPLICATION_SLOT command has been extended to support
the failover option.
These new additions allow the modification of the failover property of a
replication slot on the publisher. A subsequent commit will make use of these
commands in subscription commands.
---
doc/src/sgml/protocol.sgml | 52 ++++++++++++++++
src/backend/commands/subscriptioncmds.c | 2 +-
.../libpqwalreceiver/libpqwalreceiver.c | 38 +++++++++++-
src/backend/replication/logical/tablesync.c | 1 +
src/backend/replication/repl_gram.y | 20 +++++-
src/backend/replication/repl_scanner.l | 2 +
src/backend/replication/slot.c | 25 ++++++++
src/backend/replication/walreceiver.c | 2 +-
src/backend/replication/walsender.c | 62 ++++++++++++++++++-
src/include/nodes/replnodes.h | 12 ++++
src/include/replication/slot.h | 1 +
src/include/replication/walreceiver.h | 18 +++++-
src/tools/pgindent/typedefs.list | 2 +
13 files changed, 225 insertions(+), 12 deletions(-)
diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
index 6c3e8a631d..dc10b1956a 100644
--- a/doc/src/sgml/protocol.sgml
+++ b/doc/src/sgml/protocol.sgml
@@ -2060,6 +2060,17 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;"
</para>
</listitem>
</varlistentry>
+
+ <varlistentry>
+ <term><literal>FAILOVER [ <replaceable class="parameter">boolean</replaceable> ]</literal></term>
+ <listitem>
+ <para>
+ If true, the slot is enabled to be synced to the standbys
+ so that logical replication can be resumed after failover.
+ The default is false.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist>
<para>
@@ -2124,6 +2135,47 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;"
</listitem>
</varlistentry>
+ <varlistentry id="protocol-replication-alter-replication-slot" xreflabel="ALTER_REPLICATION_SLOT">
+ <term><literal>ALTER_REPLICATION_SLOT</literal> <replaceable class="parameter">slot_name</replaceable> ( <replaceable class="parameter">option</replaceable> [, ...] )
+ <indexterm><primary>ALTER_REPLICATION_SLOT</primary></indexterm>
+ </term>
+ <listitem>
+ <para>
+ Change the definition of a replication slot.
+ See <xref linkend="streaming-replication-slots"/> for more about
+ replication slots. This command is currently only supported for logical
+ replication slots.
+ </para>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">slot_name</replaceable></term>
+ <listitem>
+ <para>
+ The name of the slot to alter. Must be a valid replication slot
+ name (see <xref linkend="streaming-replication-slots-manipulation"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+
+ <para>The following options are supported:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>FAILOVER [ <replaceable class="parameter">boolean</replaceable> ]</literal></term>
+ <listitem>
+ <para>
+ If true, the slot is enabled to be synced to the standbys
+ so that logical replication can be resumed after failover.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+
+ </listitem>
+ </varlistentry>
+
<varlistentry id="protocol-replication-read-replication-slot">
<term><literal>READ_REPLICATION_SLOT</literal> <replaceable class="parameter">slot_name</replaceable>
<indexterm><primary>READ_REPLICATION_SLOT</primary></indexterm>
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 75e6cd8ae3..eaf2ec3b36 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -807,7 +807,7 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
twophase_enabled = true;
walrcv_create_slot(wrconn, opts.slot_name, false, twophase_enabled,
- CRS_NOEXPORT_SNAPSHOT, NULL);
+ false, CRS_NOEXPORT_SNAPSHOT, NULL);
if (twophase_enabled)
UpdateTwoPhaseState(subid, LOGICALREP_TWOPHASE_STATE_ENABLED);
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 77669074e8..20d5128c0e 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -73,8 +73,11 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
const char *slotname,
bool temporary,
bool two_phase,
+ bool failover,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
+static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
+ bool failover);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -95,6 +98,7 @@ static WalReceiverFunctionsType PQWalReceiverFunctions = {
.walrcv_receive = libpqrcv_receive,
.walrcv_send = libpqrcv_send,
.walrcv_create_slot = libpqrcv_create_slot,
+ .walrcv_alter_slot = libpqrcv_alter_slot,
.walrcv_get_backend_pid = libpqrcv_get_backend_pid,
.walrcv_exec = libpqrcv_exec,
.walrcv_disconnect = libpqrcv_disconnect
@@ -938,8 +942,8 @@ libpqrcv_send(WalReceiverConn *conn, const char *buffer, int nbytes)
*/
static char *
libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
- bool temporary, bool two_phase, CRSSnapshotAction snapshot_action,
- XLogRecPtr *lsn)
+ bool temporary, bool two_phase, bool failover,
+ CRSSnapshotAction snapshot_action, XLogRecPtr *lsn)
{
PGresult *res;
StringInfoData cmd;
@@ -968,7 +972,8 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
else
appendStringInfoChar(&cmd, ' ');
}
-
+ if (failover)
+ appendStringInfoString(&cmd, "FAILOVER, ");
if (use_new_options_syntax)
{
switch (snapshot_action)
@@ -1037,6 +1042,33 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
return snapshot;
}
+/*
+ * Change the definition of the replication slot.
+ */
+static void
+libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
+ bool failover)
+{
+ StringInfoData cmd;
+ PGresult *res;
+
+ initStringInfo(&cmd);
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s )",
+ quote_identifier(slotname),
+ failover ? "true" : "false");
+
+ res = libpqrcv_PQexec(conn->streamConn, cmd.data);
+ pfree(cmd.data);
+
+ if (PQresultStatus(res) != PGRES_COMMAND_OK)
+ ereport(ERROR,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg("could not alter replication slot \"%s\": %s",
+ slotname, pchomp(PQerrorMessage(conn->streamConn)))));
+
+ PQclear(res);
+}
+
/*
* Return PID of remote backend process.
*/
diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 06d5b3df33..4207b9356c 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -1430,6 +1430,7 @@ LogicalRepSyncTableStart(XLogRecPtr *origin_startpos)
*/
walrcv_create_slot(LogRepWorkerWalRcvConn,
slotname, false /* permanent */ , false /* two_phase */ ,
+ false,
CRS_USE_SNAPSHOT, origin_startpos);
/*
diff --git a/src/backend/replication/repl_gram.y b/src/backend/replication/repl_gram.y
index 95e126eb4d..ff3809e02f 100644
--- a/src/backend/replication/repl_gram.y
+++ b/src/backend/replication/repl_gram.y
@@ -64,6 +64,7 @@ Node *replication_parse_result;
%token K_START_REPLICATION
%token K_CREATE_REPLICATION_SLOT
%token K_DROP_REPLICATION_SLOT
+%token K_ALTER_REPLICATION_SLOT
%token K_TIMELINE_HISTORY
%token K_WAIT
%token K_TIMELINE
@@ -80,8 +81,9 @@ Node *replication_parse_result;
%type <node> command
%type <node> base_backup start_replication start_logical_replication
- create_replication_slot drop_replication_slot identify_system
- read_replication_slot timeline_history show upload_manifest
+ create_replication_slot drop_replication_slot
+ alter_replication_slot identify_system read_replication_slot
+ timeline_history show upload_manifest
%type <list> generic_option_list
%type <defelt> generic_option
%type <uintval> opt_timeline
@@ -112,6 +114,7 @@ command:
| start_logical_replication
| create_replication_slot
| drop_replication_slot
+ | alter_replication_slot
| read_replication_slot
| timeline_history
| show
@@ -259,6 +262,18 @@ drop_replication_slot:
}
;
+/* ALTER_REPLICATION_SLOT slot */
+alter_replication_slot:
+ K_ALTER_REPLICATION_SLOT IDENT '(' generic_option_list ')'
+ {
+ AlterReplicationSlotCmd *cmd;
+ cmd = makeNode(AlterReplicationSlotCmd);
+ cmd->slotname = $2;
+ cmd->options = $4;
+ $$ = (Node *) cmd;
+ }
+ ;
+
/*
* START_REPLICATION [SLOT slot] [PHYSICAL] %X/%X [TIMELINE %d]
*/
@@ -410,6 +425,7 @@ ident_or_keyword:
| K_START_REPLICATION { $$ = "start_replication"; }
| K_CREATE_REPLICATION_SLOT { $$ = "create_replication_slot"; }
| K_DROP_REPLICATION_SLOT { $$ = "drop_replication_slot"; }
+ | K_ALTER_REPLICATION_SLOT { $$ = "alter_replication_slot"; }
| K_TIMELINE_HISTORY { $$ = "timeline_history"; }
| K_WAIT { $$ = "wait"; }
| K_TIMELINE { $$ = "timeline"; }
diff --git a/src/backend/replication/repl_scanner.l b/src/backend/replication/repl_scanner.l
index 6fa625617b..e7def80065 100644
--- a/src/backend/replication/repl_scanner.l
+++ b/src/backend/replication/repl_scanner.l
@@ -125,6 +125,7 @@ TIMELINE { return K_TIMELINE; }
START_REPLICATION { return K_START_REPLICATION; }
CREATE_REPLICATION_SLOT { return K_CREATE_REPLICATION_SLOT; }
DROP_REPLICATION_SLOT { return K_DROP_REPLICATION_SLOT; }
+ALTER_REPLICATION_SLOT { return K_ALTER_REPLICATION_SLOT; }
TIMELINE_HISTORY { return K_TIMELINE_HISTORY; }
PHYSICAL { return K_PHYSICAL; }
RESERVE_WAL { return K_RESERVE_WAL; }
@@ -302,6 +303,7 @@ replication_scanner_is_replication_command(void)
case K_START_REPLICATION:
case K_CREATE_REPLICATION_SLOT:
case K_DROP_REPLICATION_SLOT:
+ case K_ALTER_REPLICATION_SLOT:
case K_READ_REPLICATION_SLOT:
case K_TIMELINE_HISTORY:
case K_UPLOAD_MANIFEST:
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 02a14ec210..f2781d0455 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -683,6 +683,31 @@ ReplicationSlotDrop(const char *name, bool nowait)
ReplicationSlotDropAcquired();
}
+/*
+ * Change the definition of the slot identified by the specified name.
+ */
+void
+ReplicationSlotAlter(const char *name, bool failover)
+{
+ Assert(MyReplicationSlot == NULL);
+
+ ReplicationSlotAcquire(name, false);
+
+ if (SlotIsPhysical(MyReplicationSlot))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot use %s with a physical replication slot",
+ "ALTER_REPLICATION_SLOT"));
+
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.failover = failover;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ ReplicationSlotMarkDirty();
+ ReplicationSlotSave();
+ ReplicationSlotRelease();
+}
+
/*
* Permanently drop the currently acquired replication slot.
*/
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 728059518e..e29a6196a3 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -387,7 +387,7 @@ WalReceiverMain(void)
"pg_walreceiver_%lld",
(long long int) walrcv_get_backend_pid(wrconn));
- walrcv_create_slot(wrconn, slotname, true, false, 0, NULL);
+ walrcv_create_slot(wrconn, slotname, true, false, false, 0, NULL);
SpinLockAcquire(&walrcv->mutex);
strlcpy(walrcv->slotname, slotname, NAMEDATALEN);
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index aa80f3de20..77c8baa32a 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1126,12 +1126,13 @@ static void
parseCreateReplSlotOptions(CreateReplicationSlotCmd *cmd,
bool *reserve_wal,
CRSSnapshotAction *snapshot_action,
- bool *two_phase)
+ bool *two_phase, bool *failover)
{
ListCell *lc;
bool snapshot_action_given = false;
bool reserve_wal_given = false;
bool two_phase_given = false;
+ bool failover_given = false;
/* Parse options */
foreach(lc, cmd->options)
@@ -1181,6 +1182,15 @@ parseCreateReplSlotOptions(CreateReplicationSlotCmd *cmd,
two_phase_given = true;
*two_phase = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "failover") == 0)
+ {
+ if (failover_given || cmd->kind != REPLICATION_KIND_LOGICAL)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ failover_given = true;
+ *failover = defGetBoolean(defel);
+ }
else
elog(ERROR, "unrecognized option: %s", defel->defname);
}
@@ -1197,6 +1207,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
char *slot_name;
bool reserve_wal = false;
bool two_phase = false;
+ bool failover = false;
CRSSnapshotAction snapshot_action = CRS_EXPORT_SNAPSHOT;
DestReceiver *dest;
TupOutputState *tstate;
@@ -1206,7 +1217,8 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
Assert(!MyReplicationSlot);
- parseCreateReplSlotOptions(cmd, &reserve_wal, &snapshot_action, &two_phase);
+ parseCreateReplSlotOptions(cmd, &reserve_wal, &snapshot_action, &two_phase,
+ &failover);
if (cmd->kind == REPLICATION_KIND_PHYSICAL)
{
@@ -1243,7 +1255,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
*/
ReplicationSlotCreate(cmd->slotname, true,
cmd->temporary ? RS_TEMPORARY : RS_EPHEMERAL,
- two_phase, false);
+ two_phase, failover);
/*
* Do options check early so that we can bail before calling the
@@ -1398,6 +1410,43 @@ DropReplicationSlot(DropReplicationSlotCmd *cmd)
ReplicationSlotDrop(cmd->slotname, !cmd->wait);
}
+/*
+ * Process extra options given to ALTER_REPLICATION_SLOT.
+ */
+static void
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+{
+ bool failover_given = false;
+
+ /* Parse options */
+ foreach_ptr(DefElem, defel, cmd->options)
+ {
+ if (strcmp(defel->defname, "failover") == 0)
+ {
+ if (failover_given)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ failover_given = true;
+ *failover = defGetBoolean(defel);
+ }
+ else
+ elog(ERROR, "unrecognized option: %s", defel->defname);
+ }
+}
+
+/*
+ * Change the definition of a replication slot.
+ */
+static void
+AlterReplicationSlot(AlterReplicationSlotCmd *cmd)
+{
+ bool failover = false;
+
+ ParseAlterReplSlotOptions(cmd, &failover);
+ ReplicationSlotAlter(cmd->slotname, failover);
+}
+
/*
* Load previously initiated logical slot and prepare for sending data (via
* WalSndLoop).
@@ -1971,6 +2020,13 @@ exec_replication_command(const char *cmd_string)
EndReplicationCommand(cmdtag);
break;
+ case T_AlterReplicationSlotCmd:
+ cmdtag = "ALTER_REPLICATION_SLOT";
+ set_ps_display(cmdtag);
+ AlterReplicationSlot((AlterReplicationSlotCmd *) cmd_node);
+ EndReplicationCommand(cmdtag);
+ break;
+
case T_StartReplicationCmd:
{
StartReplicationCmd *cmd = (StartReplicationCmd *) cmd_node;
diff --git a/src/include/nodes/replnodes.h b/src/include/nodes/replnodes.h
index af0a333f1a..ed23333e92 100644
--- a/src/include/nodes/replnodes.h
+++ b/src/include/nodes/replnodes.h
@@ -72,6 +72,18 @@ typedef struct DropReplicationSlotCmd
} DropReplicationSlotCmd;
+/* ----------------------
+ * ALTER_REPLICATION_SLOT command
+ * ----------------------
+ */
+typedef struct AlterReplicationSlotCmd
+{
+ NodeTag type;
+ char *slotname;
+ List *options;
+} AlterReplicationSlotCmd;
+
+
/* ----------------------
* START_REPLICATION command
* ----------------------
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index f2501be553..72ef4859ee 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -227,6 +227,7 @@ extern void ReplicationSlotCreate(const char *name, bool db_specific,
bool two_phase, bool failover);
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
+extern void ReplicationSlotAlter(const char *name, bool failover);
extern void ReplicationSlotAcquire(const char *name, bool nowait);
extern void ReplicationSlotRelease(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 0899891cdb..f566a99ba1 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -355,9 +355,20 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
const char *slotname,
bool temporary,
bool two_phase,
+ bool failover,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
+/*
+ * walrcv_alter_slot_fn
+ *
+ * Change the definition of a replication slot. Currently, it only supports
+ * changing the failover property of the slot.
+ */
+typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
+ const char *slotname,
+ bool failover);
+
/*
* walrcv_get_backend_pid_fn
*
@@ -399,6 +410,7 @@ typedef struct WalReceiverFunctionsType
walrcv_receive_fn walrcv_receive;
walrcv_send_fn walrcv_send;
walrcv_create_slot_fn walrcv_create_slot;
+ walrcv_alter_slot_fn walrcv_alter_slot;
walrcv_get_backend_pid_fn walrcv_get_backend_pid;
walrcv_exec_fn walrcv_exec;
walrcv_disconnect_fn walrcv_disconnect;
@@ -428,8 +440,10 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_receive(conn, buffer, wait_fd)
#define walrcv_send(conn, buffer, nbytes) \
WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
-#define walrcv_create_slot(conn, slotname, temporary, two_phase, snapshot_action, lsn) \
- WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, snapshot_action, lsn)
+#define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
+ WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
+#define walrcv_alter_slot(conn, slotname, failover) \
+ WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
#define walrcv_get_backend_pid(conn) \
WalReceiverFunctions->walrcv_get_backend_pid(conn)
#define walrcv_exec(conn, exec, nRetTypes, retTypes) \
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 7e866e3c3d..513c7702ff 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -85,6 +85,7 @@ AlterOwnerStmt
AlterPolicyStmt
AlterPublicationAction
AlterPublicationStmt
+AlterReplicationSlotCmd
AlterRoleSetStmt
AlterRoleStmt
AlterSeqStmt
@@ -3880,6 +3881,7 @@ varattrib_1b_e
varattrib_4b
vbits
verifier_context
+walrcv_alter_slot_fn
walrcv_check_conninfo_fn
walrcv_connect_fn
walrcv_create_slot_fn
--
2.30.0.windows.2
[application/octet-stream] v68-0003-Add-a-failover-option-to-subscriptions.patch (63.7K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/8-v68-0003-Add-a-failover-option-to-subscriptions.patch)
download | inline diff:
From d339f14d96ff2b1155d38e6cf0fa2de4173a55d0 Mon Sep 17 00:00:00 2001
From: Hou Zhijie <[email protected]>
Date: Wed, 24 Jan 2024 20:51:39 +0800
Subject: [PATCH v68 3/8] Add a failover option to subscriptions.
This commit introduces a new subscription option named 'failover', which
provides users with the ability to set the failover property of the replication
slot on the publisher when creating or altering a subscription.
---
doc/src/sgml/catalogs.sgml | 11 ++
doc/src/sgml/ref/alter_subscription.sgml | 16 +-
doc/src/sgml/ref/create_subscription.sgml | 12 ++
src/backend/catalog/pg_subscription.c | 1 +
src/backend/catalog/system_views.sql | 3 +-
src/backend/commands/subscriptioncmds.c | 106 ++++++++++-
src/backend/replication/logical/tablesync.c | 2 +-
src/backend/replication/logical/worker.c | 7 +
src/bin/pg_dump/pg_dump.c | 18 +-
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_upgrade/t/003_logical_slots.pl | 6 +-
src/bin/psql/describe.c | 8 +-
src/bin/psql/tab-complete.c | 4 +-
src/include/catalog/pg_subscription.h | 9 +
.../t/050_standby_failover_slots_sync.pl | 89 ++++++++++
src/test/regress/expected/subscription.out | 165 ++++++++++--------
src/test/regress/sql/subscription.sql | 8 +
17 files changed, 375 insertions(+), 91 deletions(-)
create mode 100644 src/test/recovery/t/050_standby_failover_slots_sync.pl
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index c15d861e82..49d8cc6826 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -7990,6 +7990,17 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>subfailover</structfield> <type>bool</type>
+ </para>
+ <para>
+ If true, the associated replication slots (i.e. the main slot and the
+ table sync slots) in the upstream database are enabled to be
+ synchronized to the standbys
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>subconninfo</structfield> <type>text</type>
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 6d36ff0dc9..b3e779df70 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -226,10 +226,22 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-streaming"><literal>streaming</literal></link>,
<link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>,
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
- <link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>, and
- <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>.
+ <link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
+ <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
</para>
+
+ <para>
+ When altering the
+ <link linkend="sql-createsubscription-params-with-slot-name"><literal>slot_name</literal></link>,
+ the <literal>failover</literal> property value of the named slot may differ from the
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
+ parameter specified in the subscription. When creating the slot,
+ ensure the slot <literal>failover</literal> property matches the
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
+ parameter value of the subscription.
+ </para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml
index c7ace922f9..59a9554bf0 100644
--- a/doc/src/sgml/ref/create_subscription.sgml
+++ b/doc/src/sgml/ref/create_subscription.sgml
@@ -400,6 +400,18 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
</para>
</listitem>
</varlistentry>
+
+ <varlistentry id="sql-createsubscription-params-with-failover">
+ <term><literal>failover</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ Specifies whether the replication slots associated with the subscription
+ are enabled to be synced to the standbys so that logical
+ replication can be resumed from the new primary after failover.
+ The default is <literal>false</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist></para>
</listitem>
diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index c516c25ac7..406a3c2dd1 100644
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -73,6 +73,7 @@ GetSubscription(Oid subid, bool missing_ok)
sub->disableonerr = subform->subdisableonerr;
sub->passwordrequired = subform->subpasswordrequired;
sub->runasowner = subform->subrunasowner;
+ sub->failover = subform->subfailover;
/* Get conninfo */
datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index d0f711a619..e43a93739d 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1358,7 +1358,8 @@ REVOKE ALL ON pg_subscription FROM public;
GRANT SELECT (oid, subdbid, subskiplsn, subname, subowner, subenabled,
subbinary, substream, subtwophasestate, subdisableonerr,
subpasswordrequired, subrunasowner,
- subslotname, subsynccommit, subpublications, suborigin)
+ subslotname, subsynccommit, subpublications, suborigin,
+ subfailover)
ON pg_subscription TO public;
CREATE VIEW pg_stat_subscription_stats AS
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index eaf2ec3b36..15bb10da54 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -71,6 +71,7 @@
#define SUBOPT_RUN_AS_OWNER 0x00001000
#define SUBOPT_LSN 0x00002000
#define SUBOPT_ORIGIN 0x00004000
+#define SUBOPT_FAILOVER 0x00008000
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
@@ -96,6 +97,7 @@ typedef struct SubOpts
bool passwordrequired;
bool runasowner;
char *origin;
+ bool failover;
XLogRecPtr lsn;
} SubOpts;
@@ -157,6 +159,8 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->runasowner = false;
if (IsSet(supported_opts, SUBOPT_ORIGIN))
opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+ if (IsSet(supported_opts, SUBOPT_FAILOVER))
+ opts->failover = false;
/* Parse options */
foreach(lc, stmt_options)
@@ -326,6 +330,15 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized origin value: \"%s\"", opts->origin));
}
+ else if (IsSet(supported_opts, SUBOPT_FAILOVER) &&
+ strcmp(defel->defname, "failover") == 0)
+ {
+ if (IsSet(opts->specified_opts, SUBOPT_FAILOVER))
+ errorConflictingDefElem(defel, pstate);
+
+ opts->specified_opts |= SUBOPT_FAILOVER;
+ opts->failover = defGetBoolean(defel);
+ }
else if (IsSet(supported_opts, SUBOPT_LSN) &&
strcmp(defel->defname, "lsn") == 0)
{
@@ -591,7 +604,8 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
SUBOPT_DISABLE_ON_ERR | SUBOPT_PASSWORD_REQUIRED |
- SUBOPT_RUN_AS_OWNER | SUBOPT_ORIGIN);
+ SUBOPT_RUN_AS_OWNER | SUBOPT_ORIGIN |
+ SUBOPT_FAILOVER);
parse_subscription_options(pstate, stmt->options, supported_opts, &opts);
/*
@@ -710,6 +724,8 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
publicationListToArray(publications);
values[Anum_pg_subscription_suborigin - 1] =
CStringGetTextDatum(opts.origin);
+ values[Anum_pg_subscription_subfailover - 1] =
+ BoolGetDatum(opts.failover);
tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
@@ -807,7 +823,7 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
twophase_enabled = true;
walrcv_create_slot(wrconn, opts.slot_name, false, twophase_enabled,
- false, CRS_NOEXPORT_SNAPSHOT, NULL);
+ opts.failover, CRS_NOEXPORT_SNAPSHOT, NULL);
if (twophase_enabled)
UpdateTwoPhaseState(subid, LOGICALREP_TWOPHASE_STATE_ENABLED);
@@ -816,6 +832,24 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
(errmsg("created replication slot \"%s\" on publisher",
opts.slot_name)));
}
+
+ /*
+ * If the slot_name is specified without the create_slot option,
+ * it is possible that the user intends to use an existing slot on
+ * the publisher, so here we alter the failover property of the
+ * slot to match the failover value in subscription.
+ *
+ * We do not need to change the failover to false if the server
+ * does not support failover (e.g. pre-PG17).
+ */
+ else if (opts.slot_name &&
+ (opts.failover || walrcv_server_version(wrconn) >= 170000))
+ {
+ walrcv_alter_slot(wrconn, opts.slot_name, opts.failover);
+ ereport(NOTICE,
+ (errmsg("changed the failover state of replication slot \"%s\" on publisher to %s",
+ opts.slot_name, opts.failover ? "true" : "false")));
+ }
}
PG_FINALLY();
{
@@ -1132,7 +1166,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
- SUBOPT_RUN_AS_OWNER | SUBOPT_ORIGIN);
+ SUBOPT_RUN_AS_OWNER | SUBOPT_ORIGIN |
+ SUBOPT_FAILOVER);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
@@ -1218,6 +1253,31 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
replaces[Anum_pg_subscription_suborigin - 1] = true;
}
+ if (IsSet(opts.specified_opts, SUBOPT_FAILOVER))
+ {
+ if (!sub->slotname)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for a subscription that does not have a slot name",
+ "failover")));
+
+ /*
+ * Do not allow changing the failover state if the
+ * subscription is enabled. This is because the failover
+ * state of the slot on the publisher cannot be modified
+ * if the slot is currently acquired by the apply worker.
+ */
+ if (sub->enabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "failover")));
+
+ values[Anum_pg_subscription_subfailover - 1] =
+ BoolGetDatum(opts.failover);
+ replaces[Anum_pg_subscription_subfailover - 1] = true;
+ }
+
update_tuple = true;
break;
}
@@ -1453,6 +1513,46 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
heap_freetuple(tup);
}
+ /*
+ * Try to acquire the connection necessary for altering slot.
+ *
+ * This has to be at the end because otherwise if there is an error while
+ * doing the database operations we won't be able to rollback altered
+ * slot.
+ */
+ if (replaces[Anum_pg_subscription_subfailover - 1])
+ {
+ bool must_use_password;
+ char *err;
+ WalReceiverConn *wrconn;
+
+ /* Load the library providing us libpq calls. */
+ load_file("libpqwalreceiver", false);
+
+ /* Try to connect to the publisher. */
+ must_use_password = sub->passwordrequired && !sub->ownersuperuser;
+ wrconn = walrcv_connect(sub->conninfo, true, must_use_password,
+ sub->name, &err);
+ if (!wrconn)
+ ereport(ERROR,
+ (errcode(ERRCODE_CONNECTION_FAILURE),
+ errmsg("could not connect to the publisher: %s", err)));
+
+ PG_TRY();
+ {
+ walrcv_alter_slot(wrconn, sub->slotname, opts.failover);
+
+ ereport(NOTICE,
+ (errmsg("changed the failover state of replication slot \"%s\" on publisher to %s",
+ sub->slotname, opts.failover ? "true" : "false")));
+ }
+ PG_FINALLY();
+ {
+ walrcv_disconnect(wrconn);
+ }
+ PG_END_TRY();
+ }
+
table_close(rel, RowExclusiveLock);
ObjectAddressSet(myself, SubscriptionRelationId, subid);
diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 4207b9356c..5acab3f3e2 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -1430,7 +1430,7 @@ LogicalRepSyncTableStart(XLogRecPtr *origin_startpos)
*/
walrcv_create_slot(LogRepWorkerWalRcvConn,
slotname, false /* permanent */ , false /* two_phase */ ,
- false,
+ MySubscription->failover,
CRS_USE_SNAPSHOT, origin_startpos);
/*
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 9b598caf3c..32ff4c0336 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -132,6 +132,13 @@
* avoid such deadlocks, we generate a unique GID (consisting of the
* subscription oid and the xid of the prepared transaction) for each prepare
* transaction on the subscriber.
+ *
+ * FAILOVER
+ * ----------------------
+ * The logical slot on the primary can be synced to the standby by specifying
+ * failover = true when creating the subscription. Enabling failover allows us
+ * to smoothly transition to the promoted standby, ensuring that we can
+ * subscribe to the new primary without losing any data.
*-------------------------------------------------------------------------
*/
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index bc20a025ce..339f20e5e6 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4641,6 +4641,7 @@ getSubscriptions(Archive *fout)
int i_suborigin;
int i_suboriginremotelsn;
int i_subenabled;
+ int i_subfailover;
int i,
ntups;
@@ -4706,10 +4707,17 @@ getSubscriptions(Archive *fout)
if (dopt->binary_upgrade && fout->remoteVersion >= 170000)
appendPQExpBufferStr(query, " o.remote_lsn AS suboriginremotelsn,\n"
- " s.subenabled\n");
+ " s.subenabled,\n");
else
appendPQExpBufferStr(query, " NULL AS suboriginremotelsn,\n"
- " false AS subenabled\n");
+ " false AS subenabled,\n");
+
+ if (fout->remoteVersion >= 170000)
+ appendPQExpBufferStr(query,
+ " s.subfailover\n");
+ else
+ appendPQExpBuffer(query,
+ " false AS subfailover\n");
appendPQExpBufferStr(query,
"FROM pg_subscription s\n");
@@ -4748,6 +4756,7 @@ getSubscriptions(Archive *fout)
i_suborigin = PQfnumber(res, "suborigin");
i_suboriginremotelsn = PQfnumber(res, "suboriginremotelsn");
i_subenabled = PQfnumber(res, "subenabled");
+ i_subfailover = PQfnumber(res, "subfailover");
subinfo = pg_malloc(ntups * sizeof(SubscriptionInfo));
@@ -4792,6 +4801,8 @@ getSubscriptions(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_suboriginremotelsn));
subinfo[i].subenabled =
pg_strdup(PQgetvalue(res, i, i_subenabled));
+ subinfo[i].subfailover =
+ pg_strdup(PQgetvalue(res, i, i_subfailover));
/* Decide whether we want to dump it */
selectDumpableObject(&(subinfo[i].dobj), fout);
@@ -5020,6 +5031,9 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
if (strcmp(subinfo->subtwophasestate, two_phase_disabled) != 0)
appendPQExpBufferStr(query, ", two_phase = on");
+ if (strcmp(subinfo->subfailover, "t") == 0)
+ appendPQExpBufferStr(query, ", failover = true");
+
if (strcmp(subinfo->subdisableonerr, "t") == 0)
appendPQExpBufferStr(query, ", disable_on_error = true");
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index f0772d2157..24e1643794 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -665,6 +665,7 @@ typedef struct _SubscriptionInfo
char *subpublications;
char *suborigin;
char *suboriginremotelsn;
+ char *subfailover;
} SubscriptionInfo;
/*
diff --git a/src/bin/pg_upgrade/t/003_logical_slots.pl b/src/bin/pg_upgrade/t/003_logical_slots.pl
index 0ab368247b..83d71c3084 100644
--- a/src/bin/pg_upgrade/t/003_logical_slots.pl
+++ b/src/bin/pg_upgrade/t/003_logical_slots.pl
@@ -172,7 +172,7 @@ $sub->start;
$sub->safe_psql(
'postgres', qq[
CREATE TABLE tbl (a int);
- CREATE SUBSCRIPTION regress_sub CONNECTION '$old_connstr' PUBLICATION regress_pub WITH (two_phase = 'true')
+ CREATE SUBSCRIPTION regress_sub CONNECTION '$old_connstr' PUBLICATION regress_pub WITH (two_phase = 'true', failover = 'true')
]);
$sub->wait_for_subscription_sync($oldpub, 'regress_sub');
@@ -192,8 +192,8 @@ command_ok([@pg_upgrade_cmd], 'run of pg_upgrade of old cluster');
# Check that the slot 'regress_sub' has migrated to the new cluster
$newpub->start;
my $result = $newpub->safe_psql('postgres',
- "SELECT slot_name, two_phase FROM pg_replication_slots");
-is($result, qq(regress_sub|t), 'check the slot exists on new cluster');
+ "SELECT slot_name, two_phase, failover FROM pg_replication_slots");
+is($result, qq(regress_sub|t|t), 'check the slot exists on new cluster');
# Update the connection
my $new_connstr = $newpub->connstr . ' dbname=postgres';
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 37f9516320..6d9ad5d74e 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -6563,7 +6563,8 @@ describeSubscriptions(const char *pattern, bool verbose)
PGresult *res;
printQueryOpt myopt = pset.popt;
static const bool translate_columns[] = {false, false, false, false,
- false, false, false, false, false, false, false, false, false, false};
+ false, false, false, false, false, false, false, false, false, false,
+ false};
if (pset.sversion < 100000)
{
@@ -6627,6 +6628,11 @@ describeSubscriptions(const char *pattern, bool verbose)
gettext_noop("Password required"),
gettext_noop("Run as owner?"));
+ if (pset.sversion >= 170000)
+ appendPQExpBuffer(&buf,
+ ", subfailover AS \"%s\"\n",
+ gettext_noop("Failover"));
+
appendPQExpBuffer(&buf,
", subsynccommit AS \"%s\"\n"
", subconninfo AS \"%s\"\n",
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index ada711d02f..151a5211ee 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1943,7 +1943,7 @@ psql_completion(const char *text, int start, int end)
COMPLETE_WITH("(", "PUBLICATION");
/* ALTER SUBSCRIPTION <name> SET ( */
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SET", "("))
- COMPLETE_WITH("binary", "disable_on_error", "origin",
+ COMPLETE_WITH("binary", "disable_on_error", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
"streaming", "synchronous_commit");
/* ALTER SUBSCRIPTION <name> SKIP ( */
@@ -3340,7 +3340,7 @@ psql_completion(const char *text, int start, int end)
/* Complete "CREATE SUBSCRIPTION <name> ... WITH ( <opt>" */
else if (HeadMatches("CREATE", "SUBSCRIPTION") && TailMatches("WITH", "("))
COMPLETE_WITH("binary", "connect", "copy_data", "create_slot",
- "disable_on_error", "enabled", "origin",
+ "disable_on_error", "enabled", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
"streaming", "synchronous_commit", "two_phase");
diff --git a/src/include/catalog/pg_subscription.h b/src/include/catalog/pg_subscription.h
index ab206bad7d..4d0e364624 100644
--- a/src/include/catalog/pg_subscription.h
+++ b/src/include/catalog/pg_subscription.h
@@ -93,6 +93,11 @@ CATALOG(pg_subscription,6100,SubscriptionRelationId) BKI_SHARED_RELATION BKI_ROW
bool subrunasowner; /* True if replication should execute as the
* subscription owner */
+ bool subfailover; /* True if the associated replication slots
+ * (i.e. the main slot and the table sync
+ * slots) in the upstream database are enabled
+ * to be synchronized to the standbys. */
+
#ifdef CATALOG_VARLEN /* variable-length fields start here */
/* Connection string to the publisher */
text subconninfo BKI_FORCE_NOT_NULL;
@@ -148,6 +153,10 @@ typedef struct Subscription
List *publications; /* List of publication names to subscribe to */
char *origin; /* Only publish data originating from the
* specified origin */
+ bool failover; /* True if the associated replication slots
+ * (i.e. the main slot and the table sync
+ * slots) in the upstream database are enabled
+ * to be synchronized to the standbys. */
} Subscription;
/* Disallow streaming in-progress transactions. */
diff --git a/src/test/recovery/t/050_standby_failover_slots_sync.pl b/src/test/recovery/t/050_standby_failover_slots_sync.pl
new file mode 100644
index 0000000000..646293c39e
--- /dev/null
+++ b/src/test/recovery/t/050_standby_failover_slots_sync.pl
@@ -0,0 +1,89 @@
+
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+use strict;
+use warnings;
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+##################################################
+# Test that when a subscription with failover enabled is created, it will alter
+# the failover property of the corresponding slot on the publisher.
+##################################################
+
+# Create publisher
+my $publisher = PostgreSQL::Test::Cluster->new('publisher');
+$publisher->init(allows_streaming => 'logical');
+$publisher->start;
+
+$publisher->safe_psql('postgres',
+ "CREATE PUBLICATION regress_mypub FOR ALL TABLES;"
+);
+
+my $publisher_connstr = $publisher->connstr . ' dbname=postgres';
+
+# Create a subscriber node, wait for sync to complete
+my $subscriber1 = PostgreSQL::Test::Cluster->new('subscriber1');
+$subscriber1->init;
+$subscriber1->start;
+
+# Create a slot on the publisher with failover disabled
+$publisher->safe_psql('postgres',
+ "SELECT 'init' FROM pg_create_logical_replication_slot('lsub1_slot', 'pgoutput', false, false, false);"
+);
+
+# Confirm that the failover flag on the slot is turned off
+is( $publisher->safe_psql(
+ 'postgres',
+ q{SELECT failover from pg_replication_slots WHERE slot_name = 'lsub1_slot';}
+ ),
+ "f",
+ 'logical slot has failover false on the publisher');
+
+# Create a subscription (using the same slot created above) that enables
+# failover.
+$subscriber1->safe_psql('postgres',
+ "CREATE SUBSCRIPTION regress_mysub1 CONNECTION '$publisher_connstr' PUBLICATION regress_mypub WITH (slot_name = lsub1_slot, copy_data=false, failover = true, create_slot = false, enabled = false);"
+);
+
+# Confirm that the failover flag on the slot has now been turned on
+is( $publisher->safe_psql(
+ 'postgres',
+ q{SELECT failover from pg_replication_slots WHERE slot_name = 'lsub1_slot';}
+ ),
+ "t",
+ 'logical slot has failover true on the publisher');
+
+##################################################
+# Test that changing the failover property of a subscription updates the
+# corresponding failover property of the slot.
+##################################################
+
+# Disable failover
+$subscriber1->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_mysub1 SET (failover = false)");
+
+# Confirm that the failover flag on the slot has now been turned off
+is( $publisher->safe_psql(
+ 'postgres',
+ q{SELECT failover from pg_replication_slots WHERE slot_name = 'lsub1_slot';}
+ ),
+ "f",
+ 'logical slot has failover false on the publisher');
+
+# Enable failover
+$subscriber1->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_mysub1 SET (failover = true)");
+
+# Confirm that the failover flag on the slot has now been turned on
+is( $publisher->safe_psql(
+ 'postgres',
+ q{SELECT failover from pg_replication_slots WHERE slot_name = 'lsub1_slot';}
+ ),
+ "t",
+ 'logical slot has failover true on the publisher');
+
+$subscriber1->safe_psql('postgres', "DROP SUBSCRIPTION regress_mysub1");
+
+done_testing();
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index b15eddbff3..5fa230a895 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -116,18 +116,18 @@ CREATE SUBSCRIPTION regress_testsub4 CONNECTION 'dbname=regress_doesnotexist' PU
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub4 SET (origin = any);
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub3;
@@ -145,10 +145,10 @@ ALTER SUBSCRIPTION regress_testsub CONNECTION 'foobar';
ERROR: invalid connection string syntax: missing "=" after "foobar" in connection info string
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET PUBLICATION testpub2, testpub3 WITH (refresh = false);
@@ -157,10 +157,10 @@ ALTER SUBSCRIPTION regress_testsub SET (slot_name = 'newname');
ALTER SUBSCRIPTION regress_testsub SET (password_required = false);
ALTER SUBSCRIPTION regress_testsub SET (run_as_owner = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (password_required = true);
@@ -176,10 +176,10 @@ ERROR: unrecognized subscription parameter: "create_slot"
-- ok
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/12345');
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist2 | 0/12345
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/12345
(1 row)
-- ok - with lsn = NONE
@@ -188,10 +188,10 @@ ALTER SUBSCRIPTION regress_testsub SKIP (lsn = NONE);
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/0');
ERROR: invalid WAL location (LSN): 0/0
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
BEGIN;
@@ -223,10 +223,10 @@ ALTER SUBSCRIPTION regress_testsub_foo SET (synchronous_commit = foobar);
ERROR: invalid value for parameter "synchronous_commit": "foobar"
HINT: Available values: local, remote_write, remote_apply, on, off.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
----------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+------------------------------+----------
- regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | local | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+---------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
+ regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | local | dbname=regress_doesnotexist2 | 0/0
(1 row)
-- rename back to keep the rest simple
@@ -255,19 +255,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (binary = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -279,27 +279,27 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = parallel);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication already exists
@@ -314,10 +314,10 @@ ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refr
ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refresh = false);
ERROR: publication "testpub1" is already in subscription "regress_testsub"
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication used more than once
@@ -332,10 +332,10 @@ ERROR: publication "testpub3" is not in subscription "regress_testsub"
-- ok - delete publications
ALTER SUBSCRIPTION regress_testsub DROP PUBLICATION testpub1, testpub2 WITH (refresh = false);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -371,10 +371,10 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
--fail - alter of two_phase option not supported.
@@ -383,10 +383,10 @@ ERROR: unrecognized subscription parameter: "two_phase"
-- but can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -396,10 +396,10 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -412,18 +412,31 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (disable_on_error = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+(1 row)
+
+ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
+DROP SUBSCRIPTION regress_testsub;
+-- test failover option
+CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, failover = true);
+WARNING: subscription was created, but is not connected
+HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
+\dRs+
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | t | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 444e563ff3..e4601158b3 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -290,6 +290,14 @@ ALTER SUBSCRIPTION regress_testsub SET (disable_on_error = true);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
DROP SUBSCRIPTION regress_testsub;
+-- test failover option
+CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, failover = true);
+
+\dRs+
+
+ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
+DROP SUBSCRIPTION regress_testsub;
+
-- let's do some tests with pg_create_subscription rather than superuser
SET SESSION AUTHORIZATION regress_subscription_user3;
--
2.30.0.windows.2
[application/octet-stream] v68-0004-Add-logical-slot-sync-capability-to-the-physical.patch (88.6K, ../OS0PR01MB5716E304C26E6ACE0BE84925947A2@OS0PR01MB5716.jpnprd01.prod.outlook.com/9-v68-0004-Add-logical-slot-sync-capability-to-the-physical.patch)
download | inline diff:
From c7fcae7ff2b6aa48937991e4a26d2bd5cafe1f6d Mon Sep 17 00:00:00 2001
From: Hou Zhijie <[email protected]>
Date: Thu, 25 Jan 2024 10:27:56 +0800
Subject: [PATCH v68 4/8] Add logical slot sync capability to the physical
standby
This patch implements synchronization of logical replication slots
from the primary server to the physical standby so that logical
replication can be resumed after failover.
GUC 'enable_syncslot' enables a physical standby to synchronize failover
logical replication slots from the primary server.
The logical replication slots on the primary can be synchronized to the hot
standby by enabling the failover option during slot creation and setting
'enable_syncslot' on the standby. For the synchronization to work, it is
mandatory to have a physical replication slot between the primary and the
standby, and hot_standby_feedback must be enabled on the standby.
All the failover logical replication slots on the primary (assuming
configurations are appropriate) are automatically created on the physical
standbys and are synced periodically. Slot-sync worker on the standby server
ping the primary server at regular intervals to get the necessary
failover logical slots information and create/update the slots locally.
The nap time of the worker is tuned according to the activity on the primary.
The worker waits for a period of time before the next synchronization, with the
duration varying based on whether any slots were updated during the last
cycle.
The logical slots created by slot-sync worker on physical standbys are not
allowed to be dropped or consumed. Any attempt to perform logical decoding on
such slots will result in an error.
If a logical slot is invalidated on the primary, then that slot on the standby
is also invalidated.
If a logical slot on the primary is valid but is invalidated on the standby,
then that slot is dropped and recreated on the standby in next sync-cycle
provided the slot still exists on the primary server. It is okay to recreate
such slots as long as these are not consumable on the standby (which is the
case currently). This situation may occur due to the following reasons:
- The max_slot_wal_keep_size on the standby is insufficient to retain WAL
records from the restart_lsn of the slot.
- primary_slot_name is temporarily reset to null and the physical slot is
removed.
- The primary changes wal_level to a level lower than logical.
The slots synchronization status on the standby can be monitored using
'synced' column of pg_replication_slots view.
---
doc/src/sgml/bgworker.sgml | 65 +-
doc/src/sgml/config.sgml | 27 +-
doc/src/sgml/logicaldecoding.sgml | 37 +
doc/src/sgml/system-views.sgml | 16 +
src/backend/access/transam/xlog.c | 5 +-
src/backend/access/transam/xlogrecovery.c | 15 +
src/backend/catalog/system_views.sql | 3 +-
src/backend/postmaster/bgworker.c | 4 +
src/backend/postmaster/postmaster.c | 10 +
.../libpqwalreceiver/libpqwalreceiver.c | 41 +
src/backend/replication/logical/Makefile | 1 +
src/backend/replication/logical/logical.c | 12 +
src/backend/replication/logical/meson.build | 1 +
src/backend/replication/logical/slotsync.c | 1195 +++++++++++++++++
src/backend/replication/slot.c | 55 +-
src/backend/replication/slotfuncs.c | 26 +-
src/backend/replication/walreceiverfuncs.c | 16 +
src/backend/replication/walsender.c | 19 +-
src/backend/storage/ipc/ipci.c | 2 +
src/backend/tcop/postgres.c | 11 +
.../utils/activity/wait_event_names.txt | 1 +
src/backend/utils/misc/guc_tables.c | 10 +
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/catalog/pg_proc.dat | 6 +-
src/include/postmaster/bgworker.h | 1 +
src/include/replication/logicalworker.h | 1 +
src/include/replication/slot.h | 17 +-
src/include/replication/walreceiver.h | 11 +
src/include/replication/walsender.h | 3 +
src/include/replication/worker_internal.h | 10 +
.../t/050_standby_failover_slots_sync.pl | 166 ++-
src/test/regress/expected/rules.out | 5 +-
src/test/regress/expected/sysviews.out | 3 +-
src/tools/pgindent/typedefs.list | 2 +
34 files changed, 1753 insertions(+), 45 deletions(-)
create mode 100644 src/backend/replication/logical/slotsync.c
diff --git a/doc/src/sgml/bgworker.sgml b/doc/src/sgml/bgworker.sgml
index 2c393385a9..a7cfe6c58c 100644
--- a/doc/src/sgml/bgworker.sgml
+++ b/doc/src/sgml/bgworker.sgml
@@ -114,18 +114,59 @@ typedef struct BackgroundWorker
<para>
<structfield>bgw_start_time</structfield> is the server state during which
- <command>postgres</command> should start the process; it can be one of
- <literal>BgWorkerStart_PostmasterStart</literal> (start as soon as
- <command>postgres</command> itself has finished its own initialization; processes
- requesting this are not eligible for database connections),
- <literal>BgWorkerStart_ConsistentState</literal> (start as soon as a consistent state
- has been reached in a hot standby, allowing processes to connect to
- databases and run read-only queries), and
- <literal>BgWorkerStart_RecoveryFinished</literal> (start as soon as the system has
- entered normal read-write state). Note the last two values are equivalent
- in a server that's not a hot standby. Note that this setting only indicates
- when the processes are to be started; they do not stop when a different state
- is reached.
+ <command>postgres</command> should start the process. Note that this setting
+ only indicates when the processes are to be started; they do not stop when
+ a different state is reached. Possible values are:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>BgWorkerStart_PostmasterStart</literal></term>
+ <listitem>
+ <para>
+ <indexterm><primary>BgWorkerStart_PostmasterStart</primary></indexterm>
+ Start as soon as postgres itself has finished its own initialization;
+ processes requesting this are not eligible for database connections.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>BgWorkerStart_ConsistentState</literal></term>
+ <listitem>
+ <para>
+ <indexterm><primary>BgWorkerStart_ConsistentState</primary></indexterm>
+ Start as soon as a consistent state has been reached in a hot-standby,
+ allowing processes to connect to databases and run read-only queries.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>BgWorkerStart_ConsistentState_HotStandby</literal></term>
+ <listitem>
+ <para>
+ <indexterm><primary>BgWorkerStart_ConsistentState_HotStandby</primary></indexterm>
+ Same meaning as <literal>BgWorkerStart_ConsistentState</literal> but
+ it is more strict in terms of the server i.e. start the worker only
+ if it is hot-standby.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>BgWorkerStart_RecoveryFinished</literal></term>
+ <listitem>
+ <para>
+ <indexterm><primary>BgWorkerStart_RecoveryFinished</primary></indexterm>
+ Start as soon as the system has entered normal read-write state. Note
+ that the <literal>BgWorkerStart_ConsistentState</literal> and
+ <literal>BgWorkerStart_RecoveryFinished</literal> are equivalent
+ in a server that's not a hot standby.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
</para>
<para>
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 61038472c5..bd2d2f871e 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -4612,8 +4612,13 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
<varname>primary_conninfo</varname> string, or in a separate
<filename>~/.pgpass</filename> file on the standby server (use
<literal>replication</literal> as the database name).
- Do not specify a database name in the
- <varname>primary_conninfo</varname> string.
+ </para>
+ <para>
+ If slot synchronization is enabled (see
+ <xref linkend="guc-enable-syncslot"/>) then it is also
+ necessary to specify <literal>dbname</literal> in the
+ <varname>primary_conninfo</varname> string. This will only be used for
+ slot synchronization. It is ignored for streaming.
</para>
<para>
This parameter can only be set in the <filename>postgresql.conf</filename>
@@ -4938,6 +4943,24 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
</listitem>
</varlistentry>
+ <varlistentry id="guc-enable-syncslot" xreflabel="enable_syncslot">
+ <term><varname>enable_syncslot</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>enable_syncslot</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ It enables a physical standby to synchronize logical failover slots
+ from the primary server so that logical subscribers are not blocked
+ after failover.
+ </para>
+ <para>
+ It is disabled by default. This parameter can only be set in the
+ <filename>postgresql.conf</filename> file or on the server command line.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist>
</sect2>
diff --git a/doc/src/sgml/logicaldecoding.sgml b/doc/src/sgml/logicaldecoding.sgml
index cd152d4ced..ec14cf7325 100644
--- a/doc/src/sgml/logicaldecoding.sgml
+++ b/doc/src/sgml/logicaldecoding.sgml
@@ -358,6 +358,43 @@ postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NU
So if a slot is no longer required it should be dropped.
</para>
</caution>
+
+ </sect2>
+
+ <sect2 id="logicaldecoding-replication-slots-synchronization">
+ <title>Replication Slot Synchronization</title>
+ <para>
+ A logical replication slot on the primary can be synchronized to the hot
+ standby by enabling the <literal>failover</literal> option during slot
+ creation and setting
+ <link linkend="guc-enable-syncslot"><varname>enable_syncslot</varname></link>
+ on the standby. For the synchronization
+ to work, it is mandatory to have a physical replication slot between the
+ primary and the standby, and
+ <link linkend="guc-hot-standby-feedback"><varname>hot_standby_feedback</varname></link>
+ must be enabled on the standby.
+ </para>
+
+ <para>
+ The ability to resume logical replication after failover depends upon the
+ <link linkend="view-pg-replication-slots">pg_replication_slots</link>.<structfield>synced</structfield>
+ value for the synchronized slots on the standby at the time of failover.
+ Only persistent slots that have attained synced state as true on the standby
+ before failover can be used for logical replication after failover.
+ Temporary slots will be dropped, therefore logical replication for those
+ slots cannot be resumed. For example, if the synchronized slot could not
+ become persistent on the standby due to a disabled subscription, then the
+ subscription cannot be resumed after failover even when it is enabled.
+ </para>
+
+ <para>
+ To resume logical replication after failover from the synced logical
+ slots, the subscription's 'conninfo' must be altered to point to the
+ new primary server. This is done using
+ <link linkend="sql-altersubscription-params-connection"><command>ALTER SUBSCRIPTION ... CONNECTION</command></link>.
+ It is recommended that subscriptions are first disabled before promoting
+ the standby and are enabled back after altering the connection string.
+ </para>
</sect2>
<sect2 id="logicaldecoding-explanation-output-plugins">
diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml
index 88fe4b6341..459101af5f 100644
--- a/doc/src/sgml/system-views.sgml
+++ b/doc/src/sgml/system-views.sgml
@@ -2566,6 +2566,22 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
after failover. Always false for physical slots.
</para></entry>
</row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>synced</structfield> <type>bool</type>
+ </para>
+ <para>
+ True if this is a logical slot that was synced from a primary server.
+ </para>
+ <para>
+ On a hot standby, the slots with the synced column marked as true can
+ neither be used for logical decoding nor dropped by the user. The value
+ of this column has no meaning on the primary server; the column value on
+ the primary is default false for all slots but may (if leftover from a
+ promoted standby) also be true.
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 478377c4a2..2d66d0d84b 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -3596,6 +3596,9 @@ XLogGetLastRemovedSegno(void)
/*
* Return the oldest WAL segment on the given TLI that still exists in
* XLOGDIR, or 0 if none.
+ *
+ * If the given TLI is 0, return the oldest WAL segment among all the currently
+ * existing WAL segments.
*/
XLogSegNo
XLogGetOldestSegno(TimeLineID tli)
@@ -3619,7 +3622,7 @@ XLogGetOldestSegno(TimeLineID tli)
wal_segment_size);
/* Ignore anything that's not from the TLI of interest. */
- if (tli != file_tli)
+ if (tli != 0 && tli != file_tli)
continue;
/* If it's the oldest so far, update oldest_segno. */
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 1b48d7171a..e38a9587e2 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -50,6 +50,7 @@
#include "postmaster/startup.h"
#include "replication/slot.h"
#include "replication/walreceiver.h"
+#include "replication/worker_internal.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/latch.h"
@@ -1441,6 +1442,20 @@ FinishWalRecovery(void)
*/
XLogShutdownWalRcv();
+ /*
+ * Shutdown the slot sync workers to prevent potential conflicts between
+ * user processes and slotsync workers after a promotion.
+ *
+ * We do not update the 'synced' column from true to false here, as any
+ * failed update could leave 'synced' column false for some slots. This
+ * could cause issues during slot sync after restarting the server as a
+ * standby. While updating after switching to the new timeline is an
+ * option, it does not simplify the handling for 'synced' column.
+ * Therefore, we retain the 'synced' column as true after promotion as it
+ * may provide useful information about the slot origin.
+ */
+ ShutDownSlotSync();
+
/*
* We are now done reading the xlog from stream. Turn off streaming
* recovery to force fetching the files (which would be required at end of
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index e43a93739d..ad57bade07 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1024,7 +1024,8 @@ CREATE VIEW pg_replication_slots AS
L.safe_wal_size,
L.two_phase,
L.conflict_reason,
- L.failover
+ L.failover,
+ L.synced
FROM pg_get_replication_slots() AS L
LEFT JOIN pg_database D ON (L.datoid = D.oid);
diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c
index 67f92c24db..46828b8a89 100644
--- a/src/backend/postmaster/bgworker.c
+++ b/src/backend/postmaster/bgworker.c
@@ -21,6 +21,7 @@
#include "postmaster/postmaster.h"
#include "replication/logicallauncher.h"
#include "replication/logicalworker.h"
+#include "replication/worker_internal.h"
#include "storage/dsm.h"
#include "storage/ipc.h"
#include "storage/latch.h"
@@ -129,6 +130,9 @@ static const struct
{
"ApplyWorkerMain", ApplyWorkerMain
},
+ {
+ "ReplSlotSyncWorkerMain", ReplSlotSyncWorkerMain
+ },
{
"ParallelApplyWorkerMain", ParallelApplyWorkerMain
},
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index feb471dd1d..d90d5d1576 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -116,6 +116,7 @@
#include "postmaster/walsummarizer.h"
#include "replication/logicallauncher.h"
#include "replication/walsender.h"
+#include "replication/worker_internal.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/pg_shmem.h"
@@ -1010,6 +1011,12 @@ PostmasterMain(int argc, char *argv[])
*/
ApplyLauncherRegister();
+ /*
+ * Register the slot sync worker here to kick start slot-sync operation
+ * sooner on the physical standby.
+ */
+ SlotSyncWorkerRegister();
+
/*
* process any libraries that should be preloaded at postmaster start
*/
@@ -5799,6 +5806,9 @@ bgworker_should_start_now(BgWorkerStartTime start_time)
case PM_HOT_STANDBY:
if (start_time == BgWorkerStart_ConsistentState)
return true;
+ if (start_time == BgWorkerStart_ConsistentState_HotStandby &&
+ pmState != PM_RUN)
+ return true;
/* fall through */
case PM_RECOVERY:
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 20d5128c0e..ae76c098b1 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -33,6 +33,7 @@
#include "utils/memutils.h"
#include "utils/pg_lsn.h"
#include "utils/tuplestore.h"
+#include "utils/varlena.h"
PG_MODULE_MAGIC;
@@ -57,6 +58,7 @@ static void libpqrcv_get_senderinfo(WalReceiverConn *conn,
char **sender_host, int *sender_port);
static char *libpqrcv_identify_system(WalReceiverConn *conn,
TimeLineID *primary_tli);
+static char *libpqrcv_get_dbname_from_conninfo(const char *conninfo);
static int libpqrcv_server_version(WalReceiverConn *conn);
static void libpqrcv_readtimelinehistoryfile(WalReceiverConn *conn,
TimeLineID tli, char **filename,
@@ -99,6 +101,7 @@ static WalReceiverFunctionsType PQWalReceiverFunctions = {
.walrcv_send = libpqrcv_send,
.walrcv_create_slot = libpqrcv_create_slot,
.walrcv_alter_slot = libpqrcv_alter_slot,
+ .walrcv_get_dbname_from_conninfo = libpqrcv_get_dbname_from_conninfo,
.walrcv_get_backend_pid = libpqrcv_get_backend_pid,
.walrcv_exec = libpqrcv_exec,
.walrcv_disconnect = libpqrcv_disconnect
@@ -471,6 +474,44 @@ libpqrcv_server_version(WalReceiverConn *conn)
return PQserverVersion(conn->streamConn);
}
+/*
+ * Get database name from the primary server's conninfo.
+ *
+ * If dbname is not found in connInfo, return NULL value.
+ */
+static char *
+libpqrcv_get_dbname_from_conninfo(const char *connInfo)
+{
+ PQconninfoOption *opts;
+ char *dbname = NULL;
+ char *err = NULL;
+
+ opts = PQconninfoParse(connInfo, &err);
+ if (opts == NULL)
+ {
+ /* The error string is malloc'd, so we must free it explicitly */
+ char *errcopy = err ? pstrdup(err) : "out of memory";
+
+ PQfreemem(err);
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid connection string syntax: %s", errcopy)));
+ }
+
+ for (PQconninfoOption *opt = opts; opt->keyword != NULL; ++opt)
+ {
+ /*
+ * If multiple dbnames are specified, then the last one will be
+ * returned
+ */
+ if (strcmp(opt->keyword, "dbname") == 0 && opt->val &&
+ opt->val[0] != '\0')
+ dbname = pstrdup(opt->val);
+ }
+
+ return dbname;
+}
+
/*
* Start streaming WAL data from given streaming options.
*
diff --git a/src/backend/replication/logical/Makefile b/src/backend/replication/logical/Makefile
index 2dc25e37bb..ba03eeff1c 100644
--- a/src/backend/replication/logical/Makefile
+++ b/src/backend/replication/logical/Makefile
@@ -25,6 +25,7 @@ OBJS = \
proto.o \
relation.o \
reorderbuffer.o \
+ slotsync.o \
snapbuild.o \
tablesync.o \
worker.o
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c
index ca09c683f1..5aefb10ecb 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -524,6 +524,18 @@ CreateDecodingContext(XLogRecPtr start_lsn,
errmsg("replication slot \"%s\" was not created in this database",
NameStr(slot->data.name))));
+ /*
+ * Do not allow consumption of a "synchronized" slot until the standby
+ * gets promoted.
+ */
+ if (RecoveryInProgress() && slot->data.synced)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot use replication slot \"%s\" for logical"
+ " decoding", NameStr(slot->data.name)),
+ errdetail("This slot is being synced from the primary server."),
+ errhint("Specify another replication slot."));
+
/*
* 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
diff --git a/src/backend/replication/logical/meson.build b/src/backend/replication/logical/meson.build
index 1050eb2c09..3dec36a6de 100644
--- a/src/backend/replication/logical/meson.build
+++ b/src/backend/replication/logical/meson.build
@@ -11,6 +11,7 @@ backend_sources += files(
'proto.c',
'relation.c',
'reorderbuffer.c',
+ 'slotsync.c',
'snapbuild.c',
'tablesync.c',
'worker.c',
diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c
new file mode 100644
index 0000000000..84b66104f7
--- /dev/null
+++ b/src/backend/replication/logical/slotsync.c
@@ -0,0 +1,1195 @@
+/*-------------------------------------------------------------------------
+ * slotsync.c
+ * PostgreSQL worker for synchronizing slots to a standby server from the
+ * primary server.
+ *
+ * Copyright (c) 2024, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/replication/logical/slotsync.c
+ *
+ * This file contains the code for slot sync worker on a physical standby
+ * to fetch logical failover slots information from the primary server,
+ * create the slots on the standby and synchronize them periodically.
+ *
+ * While creating the slot on physical standby, if the local restart_lsn and/or
+ * local catalog_xmin is ahead of those on the remote then the worker cannot
+ * create the local slot in sync with the primary server because that would
+ * mean moving the local slot backwards and the standby might not have WALs
+ * retained for old LSN. In this case, the worker will mark the slot as
+ * RS_TEMPORARY. Once the primary server catches up, the worker will mark the
+ * slot as RS_PERSISTENT (which means sync-ready) and will perform the sync
+ * periodically.
+ *
+ * The worker also takes care of dropping the slots which were created by it
+ * and are currently not needed to be synchronized.
+ *
+ * It waits for a period of time before the next synchronization, with the
+ * duration varying based on whether any slots were updated during the last
+ * cycle. Refer to the comments above wait_for_slot_activity() for more details.
+ *
+ * Slot synchronization is currently not supported on the cascading standby.
+ *---------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/genam.h"
+#include "access/table.h"
+#include "access/xlog_internal.h"
+#include "access/xlogrecovery.h"
+#include "catalog/pg_database.h"
+#include "commands/dbcommands.h"
+#include "pgstat.h"
+#include "postmaster/bgworker.h"
+#include "postmaster/interrupt.h"
+#include "replication/logical.h"
+#include "replication/logicallauncher.h"
+#include "replication/logicalworker.h"
+#include "replication/walreceiver.h"
+#include "replication/worker_internal.h"
+#include "storage/ipc.h"
+#include "storage/procarray.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/fmgroids.h"
+#include "utils/guc_hooks.h"
+#include "utils/pg_lsn.h"
+#include "utils/varlena.h"
+
+/*
+ * Structure to hold information fetched from the primary server about a logical
+ * replication slot.
+ */
+typedef struct RemoteSlot
+{
+ char *name;
+ char *plugin;
+ char *database;
+ bool two_phase;
+ XLogRecPtr restart_lsn;
+ XLogRecPtr confirmed_lsn;
+ TransactionId catalog_xmin;
+
+ /* RS_INVAL_NONE if valid, or the reason of invalidation */
+ ReplicationSlotInvalidationCause invalidated;
+} RemoteSlot;
+
+/*
+ * Struct for sharing information between startup process and slot
+ * sync worker.
+ *
+ * Slot sync worker's pid is needed by the startup process in order to
+ * shut it down during promotion. Startup process shuts down the slot
+ * sync worker and also sets stopSignaled=true to handle the race condition
+ * when postmaster has not noticed the promotion yet and thus may end up
+ * restarting slot sync worker. If stopSignaled is set, the worker will
+ * exit in such a case.
+ */
+typedef struct SlotSyncWorkerCtxStruct
+{
+ pid_t pid;
+ bool stopSignaled;
+ slock_t mutex;
+} SlotSyncWorkerCtxStruct;
+
+SlotSyncWorkerCtxStruct *SlotSyncWorker = NULL;
+
+/* GUC variable */
+bool enable_syncslot = false;
+
+/* The sleep time (ms) between slot-sync cycles varies dynamically
+ * (within a MIN/MAX range) according to slot activity. See
+ * wait_for_slot_activity() for details.
+ */
+#define MIN_WORKER_NAPTIME_MS 200
+#define MAX_WORKER_NAPTIME_MS 30000 /* 30s */
+
+static long sleep_ms = MIN_WORKER_NAPTIME_MS;
+
+static void ProcessSlotSyncInterrupts(WalReceiverConn *wrconn);
+
+/*
+ * If necessary, update local slot metadata based on the data from the remote
+ * slot.
+ *
+ * If no update was needed (the data of the remote slot is the same as the
+ * local slot) return false, otherwise true.
+ */
+static bool
+local_slot_update(RemoteSlot *remote_slot)
+{
+ Oid remote_dbid;
+ ReplicationSlot *slot = MyReplicationSlot;
+ NameData plugin_name;
+
+ Assert(slot->data.invalidated == RS_INVAL_NONE);
+
+ remote_dbid = get_database_oid(remote_slot->database, false);
+
+ if (strcmp(remote_slot->plugin, NameStr(slot->data.plugin)) == 0 &&
+ remote_dbid == slot->data.database &&
+ remote_slot->restart_lsn == slot->data.restart_lsn &&
+ remote_slot->catalog_xmin == slot->data.catalog_xmin &&
+ remote_slot->two_phase == slot->data.two_phase &&
+ remote_slot->confirmed_lsn == slot->data.confirmed_flush)
+ return false;
+
+ /*
+ * We don't want any complicated code while holding a spinlock, so do
+ * namestrcpy() outside.
+ */
+ namestrcpy(&plugin_name, remote_slot->plugin);
+
+ SpinLockAcquire(&slot->mutex);
+ slot->data.plugin = plugin_name;
+ slot->data.database = remote_dbid;
+ slot->data.two_phase = remote_slot->two_phase;
+ slot->data.restart_lsn = remote_slot->restart_lsn;
+ slot->data.confirmed_flush = remote_slot->confirmed_lsn;
+ slot->data.catalog_xmin = remote_slot->catalog_xmin;
+ slot->effective_catalog_xmin = remote_slot->catalog_xmin;
+ SpinLockRelease(&slot->mutex);
+
+ if (remote_slot->catalog_xmin != slot->data.catalog_xmin)
+ ReplicationSlotsComputeRequiredXmin(false);
+
+ if (remote_slot->restart_lsn != slot->data.restart_lsn)
+ ReplicationSlotsComputeRequiredLSN();
+
+ return true;
+}
+
+/*
+ * Get list of local logical slots which are synchronized from
+ * the primary server.
+ */
+static List *
+get_local_synced_slots(void)
+{
+ List *local_slots = NIL;
+
+ LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
+
+ for (int i = 0; i < max_replication_slots; i++)
+ {
+ ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
+
+ /* Check if it is a synchronized slot */
+ if (s->in_use && s->data.synced)
+ {
+ Assert(SlotIsLogical(s));
+ local_slots = lappend(local_slots, s);
+ }
+ }
+
+ LWLockRelease(ReplicationSlotControlLock);
+
+ return local_slots;
+}
+
+/*
+ * Helper function to check if local_slot is present in remote_slots list.
+ *
+ * It also checks if the slot on the standby server was invalidated while the
+ * corresponding remote slot in the list remained valid. If found so, it sets
+ * the locally_invalidated flag to true.
+ */
+static bool
+check_sync_slot_on_remote(ReplicationSlot *local_slot, List *remote_slots,
+ bool *locally_invalidated)
+{
+ foreach_ptr(RemoteSlot, remote_slot, remote_slots)
+ {
+ if (strcmp(remote_slot->name, NameStr(local_slot->data.name)) == 0)
+ {
+ /*
+ * If remote slot is not invalidated but local slot is marked as
+ * invalidated, then set the bool.
+ */
+ SpinLockAcquire(&local_slot->mutex);
+ *locally_invalidated =
+ (remote_slot->invalidated == RS_INVAL_NONE) &&
+ (local_slot->data.invalidated != RS_INVAL_NONE);
+ SpinLockRelease(&local_slot->mutex);
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/*
+ * Drop obsolete slots
+ *
+ * Drop the slots that no longer need to be synced i.e. these either do not
+ * exist on the primary or are no longer enabled for failover.
+ *
+ * Additionally, it drops slots that are valid on the primary but got
+ * invalidated on the standby. This situation may occur due to the following
+ * reasons:
+ * - The max_slot_wal_keep_size on the standby is insufficient to retain WAL
+ * records from the restart_lsn of the slot.
+ * - primary_slot_name is temporarily reset to null and the physical slot is
+ * removed.
+ * - The primary changes wal_level to a level lower than logical.
+ *
+ * The assumption is that these dropped slots will get recreated in next
+ * sync-cycle and it is okay to drop and recreate such slots as long as these
+ * are not consumable on the standby (which is the case currently).
+ */
+static void
+drop_obsolete_slots(List *remote_slot_list)
+{
+ List *local_slots = get_local_synced_slots();
+
+ foreach_ptr(ReplicationSlot, local_slot, local_slots)
+ {
+ bool remote_exists = false;
+ bool locally_invalidated = false;
+
+ remote_exists = check_sync_slot_on_remote(local_slot, remote_slot_list,
+ &locally_invalidated);
+
+ /*
+ * Drop the local slot either if it is not in the remote slots list or
+ * is invalidated while remote slot is still valid.
+ */
+ if (!remote_exists || locally_invalidated)
+ {
+ ReplicationSlotAcquire(NameStr(local_slot->data.name), true);
+ Assert(MyReplicationSlot->data.synced);
+ ReplicationSlotDropAcquired();
+
+ ereport(LOG,
+ errmsg("dropped replication slot \"%s\" of dbid %d",
+ NameStr(local_slot->data.name),
+ local_slot->data.database));
+ }
+ }
+}
+
+/*
+ * Reserve WAL for the currently active slot using the specified WAL location
+ * (restart_lsn).
+ *
+ * If the given WAL location has been removed, reserve WAL using the oldest
+ * existing WAL segment.
+ */
+static void
+reserve_wal_for_slot(XLogRecPtr restart_lsn)
+{
+ XLogSegNo oldest_segno;
+ XLogSegNo segno;
+ ReplicationSlot *slot = MyReplicationSlot;
+
+ Assert(slot != NULL);
+ Assert(XLogRecPtrIsInvalid(slot->data.restart_lsn));
+
+ while (true)
+ {
+ SpinLockAcquire(&slot->mutex);
+ slot->data.restart_lsn = restart_lsn;
+ SpinLockRelease(&slot->mutex);
+
+ /* Prevent WAL removal as fast as possible */
+ ReplicationSlotsComputeRequiredLSN();
+
+ XLByteToSeg(slot->data.restart_lsn, segno, wal_segment_size);
+
+ /*
+ * Find the oldest existing WAL segment file.
+ *
+ * Normally, we can determine it by using the last removed segment
+ * number. However, if no WAL segment files have been removed by a
+ * checkpoint since startup, we need to search for the oldest segment
+ * file currently existing in XLOGDIR.
+ */
+ oldest_segno = XLogGetLastRemovedSegno() + 1;
+
+ if (oldest_segno == 1)
+ oldest_segno = XLogGetOldestSegno(0);
+
+ /*
+ * If all required WAL is still there, great, otherwise retry. The
+ * slot should prevent further removal of WAL, unless there's a
+ * concurrent ReplicationSlotsComputeRequiredLSN() after we've written
+ * the new restart_lsn above, so normally we should never need to loop
+ * more than twice.
+ */
+ if (segno >= oldest_segno)
+ break;
+
+ /* Retry using the location of the oldest wal segment */
+ XLogSegNoOffsetToRecPtr(oldest_segno, 0, wal_segment_size, restart_lsn);
+ }
+}
+
+/*
+ * Update the LSNs and persist the slot for further syncs if the remote
+ * restart_lsn and catalog_xmin have caught up with the local ones, otherwise
+ * do nothing.
+ *
+ * Return true if the slot is marked as RS_PERSISTENT (sync-ready), otherwise
+ * false.
+ */
+static bool
+update_and_persist_slot(RemoteSlot *remote_slot)
+{
+ ReplicationSlot *slot = MyReplicationSlot;
+
+ /*
+ * Check if the primary server has caught up. Refer to the comment atop
+ * the file for details on this check.
+ *
+ * We also need to check if remote_slot's confirmed_lsn becomes valid. It
+ * is possible to get null values for confirmed_lsn and catalog_xmin if on
+ * the primary server the slot is just created with a valid restart_lsn
+ * and slot-sync worker has fetched the slot before the primary server
+ * could set valid confirmed_lsn and catalog_xmin.
+ */
+ if (remote_slot->restart_lsn < slot->data.restart_lsn ||
+ XLogRecPtrIsInvalid(remote_slot->confirmed_lsn) ||
+ TransactionIdPrecedes(remote_slot->catalog_xmin,
+ slot->data.catalog_xmin))
+ {
+ /*
+ * The remote slot didn't catch up to locally reserved position.
+ *
+ * We do not drop the slot because the restart_lsn can be ahead of the
+ * current location when recreating the slot in the next cycle. It may
+ * take more time to create such a slot. Therefore, we keep this slot
+ * and attempt the wait and synchronization in the next cycle.
+ */
+ return false;
+ }
+
+ /* First time slot update, the function must return true */
+ if (!local_slot_update(remote_slot))
+ elog(ERROR, "failed to update slot");
+
+ ReplicationSlotPersist();
+
+ ereport(LOG,
+ errmsg("newly created slot \"%s\" is sync-ready now",
+ remote_slot->name));
+
+ return true;
+}
+
+/*
+ * Synchronize single slot to given position.
+ *
+ * This creates a new slot if there is no existing one and updates the
+ * metadata of the slot as per the data received from the primary server.
+ *
+ * The slot is created as a temporary slot and stays in the same state until the
+ * the remote_slot catches up with locally reserved position and local slot is
+ * updated. The slot is then persisted and is considered as sync-ready for
+ * periodic syncs.
+ *
+ * Returns TRUE if the local slot is updated.
+ */
+static bool
+synchronize_one_slot(WalReceiverConn *wrconn, RemoteSlot *remote_slot)
+{
+ ReplicationSlot *slot;
+ bool slot_updated = false;
+ XLogRecPtr latestFlushPtr;
+
+ /*
+ * Sanity check: Make sure that concerned WAL is received and flushed
+ * before syncing slot to target lsn received from the primary server.
+ *
+ * This check should never pass as on the primary server, we have waited
+ * for the standby's confirmation before updating the logical slot.
+ */
+ latestFlushPtr = GetStandbyFlushRecPtr(NULL);
+ if (remote_slot->confirmed_lsn > latestFlushPtr)
+ {
+ ereport(LOG,
+ errmsg("skipping slot synchronization as the received slot sync"
+ " LSN %X/%X for slot \"%s\" is ahead of the standby position %X/%X",
+ LSN_FORMAT_ARGS(remote_slot->confirmed_lsn),
+ remote_slot->name,
+ LSN_FORMAT_ARGS(latestFlushPtr)));
+
+ return false;
+ }
+
+ /* Search for the named slot */
+ if ((slot = SearchNamedReplicationSlot(remote_slot->name, true)))
+ {
+ bool synced;
+
+ SpinLockAcquire(&slot->mutex);
+ synced = slot->data.synced;
+ SpinLockRelease(&slot->mutex);
+
+ /* User created slot with the same name exists, raise ERROR. */
+ if (!synced)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("exiting from slot synchronization because same"
+ " name slot \"%s\" already exists on the standby",
+ remote_slot->name));
+
+ /*
+ * Slot created by the slot sync worker exists, sync it.
+ *
+ * It is important to acquire the slot here before checking
+ * invalidation. If we don't acquire the slot first, there could be a
+ * race condition that the local slot could be invalidated just after
+ * checking the 'invalidated' flag here and we could end up
+ * overwriting 'invalidated' flag to remote_slot's value. See
+ * InvalidatePossiblyObsoleteSlot() where it invalidates slot directly
+ * if the slot is not acquired by other processes.
+ */
+ ReplicationSlotAcquire(remote_slot->name, true);
+
+ Assert(slot == MyReplicationSlot);
+
+ /*
+ * Copy the invalidation cause from remote only if local slot is not
+ * invalidated locally, we don't want to overwrite existing one.
+ */
+ if (slot->data.invalidated == RS_INVAL_NONE)
+ {
+ SpinLockAcquire(&slot->mutex);
+ slot->data.invalidated = remote_slot->invalidated;
+ SpinLockRelease(&slot->mutex);
+
+ /* Make sure the invalidated state persists across server restart */
+ ReplicationSlotMarkDirty();
+ ReplicationSlotSave();
+ slot_updated = true;
+ }
+
+ /* Skip the sync of an invalidated slot */
+ if (slot->data.invalidated != RS_INVAL_NONE)
+ {
+ ReplicationSlotRelease();
+ return slot_updated;
+ }
+
+ /* Slot not ready yet, let's attempt to make it sync-ready now. */
+ if (slot->data.persistency == RS_TEMPORARY)
+ {
+ slot_updated = update_and_persist_slot(remote_slot);
+ }
+
+ /* Slot ready for sync, so sync it. */
+ else
+ {
+ /*
+ * Sanity check: As long as the invalidations are handled
+ * appropriately as above, this should never happen.
+ */
+ if (remote_slot->restart_lsn < slot->data.restart_lsn)
+ elog(ERROR,
+ "cannot synchronize local slot \"%s\" LSN(%X/%X)"
+ " to remote slot's LSN(%X/%X) as synchronization"
+ " would move it backwards", remote_slot->name,
+ LSN_FORMAT_ARGS(slot->data.restart_lsn),
+ LSN_FORMAT_ARGS(remote_slot->restart_lsn));
+
+ /* Make sure the slot changes persist across server restart */
+ if (local_slot_update(remote_slot))
+ {
+ slot_updated = true;
+ ReplicationSlotMarkDirty();
+ ReplicationSlotSave();
+ }
+ }
+ }
+ /* Otherwise create the slot first. */
+ else
+ {
+ Oid dbid;
+ NameData plugin_name;
+ TransactionId xmin_horizon = InvalidTransactionId;
+
+ /* Skip creating the local slot if remote_slot is invalidated already */
+ if (remote_slot->invalidated != RS_INVAL_NONE)
+ return false;
+
+ /* Ensure that we have transaction env needed by get_database_oid() */
+ Assert(IsTransactionState());
+
+ /*
+ * It is not needed to sync 'failover' from remote_slot as currently
+ * slot synchronization is not supported on the cascading standby.
+ */
+ ReplicationSlotCreate(remote_slot->name, true, RS_TEMPORARY,
+ remote_slot->two_phase,
+ false /* failover */ ,
+ true /* synced */ );
+
+ /* For shorter lines. */
+ slot = MyReplicationSlot;
+
+ /*
+ * We don't want any complicated code while holding a spinlock, so do
+ * namestrcpy() and get_database_oid() outside.
+ */
+ namestrcpy(&plugin_name, remote_slot->plugin);
+ dbid = get_database_oid(remote_slot->database, false);
+
+ SpinLockAcquire(&slot->mutex);
+ slot->data.database = dbid;
+ slot->data.plugin = plugin_name;
+ SpinLockRelease(&slot->mutex);
+
+ reserve_wal_for_slot(remote_slot->restart_lsn);
+
+ LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
+ xmin_horizon = GetOldestSafeDecodingTransactionId(true);
+ SpinLockAcquire(&slot->mutex);
+ slot->effective_catalog_xmin = xmin_horizon;
+ slot->data.catalog_xmin = xmin_horizon;
+ SpinLockRelease(&slot->mutex);
+ ReplicationSlotsComputeRequiredXmin(true);
+ LWLockRelease(ProcArrayLock);
+
+ (void) update_and_persist_slot(remote_slot);
+ slot_updated = true;
+ }
+
+ ReplicationSlotRelease();
+
+ return slot_updated;
+}
+
+/*
+ * Maps the pg_replication_slots.conflict_reason text value to
+ * ReplicationSlotInvalidationCause enum value
+ */
+static ReplicationSlotInvalidationCause
+get_slot_invalidation_cause(char *conflict_reason)
+{
+ Assert(conflict_reason);
+
+ if (strcmp(conflict_reason, SLOT_INVAL_WAL_REMOVED_TEXT) == 0)
+ return RS_INVAL_WAL_REMOVED;
+ else if (strcmp(conflict_reason, SLOT_INVAL_HORIZON_TEXT) == 0)
+ return RS_INVAL_HORIZON;
+ else if (strcmp(conflict_reason, SLOT_INVAL_WAL_LEVEL_TEXT) == 0)
+ return RS_INVAL_WAL_LEVEL;
+ else
+ Assert(0);
+
+ /* Keep compiler quiet */
+ return RS_INVAL_NONE;
+}
+
+/*
+ * Synchronize slots.
+ *
+ * Gets the failover logical slots info from the primary server and updates
+ * the slots locally. Creates the slots if not present on the standby.
+ *
+ * Returns TRUE if any of the slots gets updated in this sync-cycle.
+ */
+static bool
+synchronize_slots(WalReceiverConn *wrconn)
+{
+#define SLOTSYNC_COLUMN_COUNT 8
+ Oid slotRow[SLOTSYNC_COLUMN_COUNT] = {TEXTOID, TEXTOID, LSNOID,
+ LSNOID, XIDOID, BOOLOID, TEXTOID, TEXTOID};
+
+ WalRcvExecResult *res;
+ TupleTableSlot *tupslot;
+ StringInfoData s;
+ List *remote_slot_list = NIL;
+ bool some_slot_updated = false;
+ XLogRecPtr latestWalEnd;
+
+ /*
+ * The primary_slot_name is not set yet or WALs not received yet.
+ * Synchronization is not possible if the walreceiver is not started.
+ */
+ latestWalEnd = GetWalRcvLatestWalEnd();
+ SpinLockAcquire(&WalRcv->mutex);
+ if ((WalRcv->slotname[0] == '\0') ||
+ XLogRecPtrIsInvalid(latestWalEnd))
+ {
+ SpinLockRelease(&WalRcv->mutex);
+ return false;
+ }
+ SpinLockRelease(&WalRcv->mutex);
+
+ /* The syscache access in walrcv_exec() needs a transaction env. */
+ StartTransactionCommand();
+
+ initStringInfo(&s);
+
+ /* Construct query to fetch slots with failover enabled. */
+ appendStringInfo(&s,
+ "SELECT slot_name, plugin, confirmed_flush_lsn,"
+ " restart_lsn, catalog_xmin, two_phase,"
+ " database, conflict_reason"
+ " FROM pg_catalog.pg_replication_slots"
+ " WHERE failover and NOT temporary");
+
+ /* Execute the query */
+ res = walrcv_exec(wrconn, s.data, SLOTSYNC_COLUMN_COUNT, slotRow);
+ pfree(s.data);
+
+ if (res->status != WALRCV_OK_TUPLES)
+ ereport(ERROR,
+ errmsg("could not fetch failover logical slots info from the primary server: %s",
+ res->err));
+
+ /* Construct the remote_slot tuple and synchronize each slot locally */
+ tupslot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
+ while (tuplestore_gettupleslot(res->tuplestore, true, false, tupslot))
+ {
+ bool isnull;
+ RemoteSlot *remote_slot = palloc0(sizeof(RemoteSlot));
+ Datum d;
+
+ remote_slot->name = TextDatumGetCString(slot_getattr(tupslot, 1, &isnull));
+ Assert(!isnull);
+
+ remote_slot->plugin = TextDatumGetCString(slot_getattr(tupslot, 2, &isnull));
+ Assert(!isnull);
+
+ /*
+ * It is possible to get null values for LSN and Xmin if slot is
+ * invalidated on the primary server, so handle accordingly.
+ */
+ d = slot_getattr(tupslot, 3, &isnull);
+ remote_slot->confirmed_lsn = isnull ? InvalidXLogRecPtr :
+ DatumGetLSN(d);
+
+ d = slot_getattr(tupslot, 4, &isnull);
+ remote_slot->restart_lsn = isnull ? InvalidXLogRecPtr : DatumGetLSN(d);
+
+ d = slot_getattr(tupslot, 5, &isnull);
+ remote_slot->catalog_xmin = isnull ? InvalidTransactionId :
+ DatumGetTransactionId(d);
+
+ remote_slot->two_phase = DatumGetBool(slot_getattr(tupslot, 6, &isnull));
+ Assert(!isnull);
+
+ remote_slot->database = TextDatumGetCString(slot_getattr(tupslot,
+ 7, &isnull));
+ Assert(!isnull);
+
+ d = slot_getattr(tupslot, 8, &isnull);
+ remote_slot->invalidated = isnull ? RS_INVAL_NONE :
+ get_slot_invalidation_cause(TextDatumGetCString(d));
+
+ /* Create list of remote slots */
+ remote_slot_list = lappend(remote_slot_list, remote_slot);
+
+ ExecClearTuple(tupslot);
+ }
+
+ /* Drop local slots that no longer need to be synced. */
+ drop_obsolete_slots(remote_slot_list);
+
+ /* Now sync the slots locally */
+ foreach_ptr(RemoteSlot, remote_slot, remote_slot_list)
+ some_slot_updated |= synchronize_one_slot(wrconn, remote_slot);
+
+ /* We are done, free remote_slot_list elements */
+ list_free_deep(remote_slot_list);
+
+ walrcv_clear_result(res);
+
+ CommitTransactionCommand();
+
+ return some_slot_updated;
+}
+
+/*
+ * Checks the primary server info.
+ *
+ * Using the specified primary server connection, check whether we are a
+ * cascading standby. It also validates primary_slot_name for non-cascading
+ * standbys.
+ */
+static void
+check_primary_info(WalReceiverConn *wrconn, bool *am_cascading_standby)
+{
+#define PRIMARY_INFO_OUTPUT_COL_COUNT 2
+ WalRcvExecResult *res;
+ Oid slotRow[PRIMARY_INFO_OUTPUT_COL_COUNT] = {BOOLOID, BOOLOID};
+ StringInfoData cmd;
+ bool isnull;
+ TupleTableSlot *tupslot;
+ bool valid;
+ bool remote_in_recovery;
+
+ /* The syscache access in walrcv_exec() needs a transaction env. */
+ StartTransactionCommand();
+
+ Assert(am_cascading_standby != NULL);
+
+ *am_cascading_standby = false; /* overwritten later if cascading */
+
+ initStringInfo(&cmd);
+ appendStringInfo(&cmd,
+ "SELECT pg_is_in_recovery(), count(*) = 1"
+ " FROM pg_replication_slots"
+ " WHERE slot_type='physical' AND slot_name=%s",
+ quote_literal_cstr(PrimarySlotName));
+
+ res = walrcv_exec(wrconn, cmd.data, PRIMARY_INFO_OUTPUT_COL_COUNT, slotRow);
+ pfree(cmd.data);
+
+ if (res->status != WALRCV_OK_TUPLES)
+ ereport(ERROR,
+ errmsg("could not fetch primary_slot_name \"%s\" info from the primary server: %s",
+ PrimarySlotName, res->err),
+ errhint("Check if \"primary_slot_name\" is configured correctly."));
+
+ tupslot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
+ if (!tuplestore_gettupleslot(res->tuplestore, true, false, tupslot))
+ elog(ERROR,
+ "failed to fetch tuple for the primary server slot specified by \"primary_slot_name\"");
+
+ remote_in_recovery = DatumGetBool(slot_getattr(tupslot, 1, &isnull));
+ Assert(!isnull);
+
+ if (remote_in_recovery)
+ {
+ /* No need to check further, just set am_cascading_standby to true */
+ *am_cascading_standby = true;
+ }
+ else
+ {
+ /* We are a normal standby */
+ valid = DatumGetBool(slot_getattr(tupslot, 2, &isnull));
+ Assert(!isnull);
+
+ if (!valid)
+ ereport(ERROR,
+ errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("exiting from slot synchronization due to bad configuration"),
+ /* translator: second %s is a GUC variable name */
+ errdetail("The primary server slot \"%s\" specified by"
+ " \"%s\" is not valid.",
+ PrimarySlotName, "primary_slot_name"));
+ }
+
+ ExecClearTuple(tupslot);
+ walrcv_clear_result(res);
+ CommitTransactionCommand();
+}
+
+/*
+ * Check that all necessary GUCs for slot synchronization are set
+ * appropriately. If not, raise an ERROR.
+ *
+ * If all checks pass, extracts the dbname from the primary_conninfo GUC and
+ * returns it.
+ */
+static char *
+validate_parameters_and_get_dbname(void)
+{
+ char *dbname;
+
+ /* Sanity check. */
+ Assert(enable_syncslot);
+
+ /*
+ * A physical replication slot(primary_slot_name) is required on the
+ * primary to ensure that the rows needed by the standby are not removed
+ * after restarting, so that the synchronized slot on the standby will not
+ * be invalidated.
+ */
+ if (PrimarySlotName == NULL || strcmp(PrimarySlotName, "") == 0)
+ ereport(ERROR,
+ /* translator: %s is a GUC variable name */
+ errmsg("exiting from slot synchronization due to bad configuration"),
+ errhint("\"%s\" must be defined.", "primary_slot_name"));
+
+ /*
+ * hot_standby_feedback must be enabled to cooperate with the physical
+ * replication slot, which allows informing the primary about the xmin and
+ * catalog_xmin values on the standby.
+ */
+ if (!hot_standby_feedback)
+ ereport(ERROR,
+ /* translator: %s is a GUC variable name */
+ errmsg("exiting from slot synchronization due to bad configuration"),
+ errhint("\"%s\" must be enabled.", "hot_standby_feedback"));
+
+ /*
+ * Logical decoding requires wal_level >= logical and we currently only
+ * synchronize logical slots.
+ */
+ if (wal_level < WAL_LEVEL_LOGICAL)
+ ereport(ERROR,
+ /* translator: %s is a GUC variable name */
+ errmsg("exiting from slot synchronization due to bad configuration"),
+ errhint("\"wal_level\" must be >= logical."));
+
+ /*
+ * The primary_conninfo is required to make connection to primary for
+ * getting slots information.
+ */
+ if (PrimaryConnInfo == NULL || strcmp(PrimaryConnInfo, "") == 0)
+ ereport(ERROR,
+ /* translator: %s is a GUC variable name */
+ errmsg("exiting from slot synchronization due to bad configuration"),
+ errhint("\"%s\" must be defined.", "primary_conninfo"));
+
+ /*
+ * The slot sync worker needs a database connection for walrcv_exec to
+ * work.
+ */
+ dbname = walrcv_get_dbname_from_conninfo(PrimaryConnInfo);
+ if (dbname == NULL)
+ ereport(ERROR,
+
+ /*
+ * translator: 'dbname' is a specific option; %s is a GUC variable
+ * name
+ */
+ errmsg("exiting from slot synchronization due to bad configuration"),
+ errhint("'dbname' must be specified in \"%s\".", "primary_conninfo"));
+
+ return dbname;
+}
+
+/*
+ * Re-read the config file.
+ *
+ * If any of the slot sync GUCs have changed, exit the worker and
+ * let it get restarted by the postmaster.
+ */
+static void
+slotsync_reread_config(void)
+{
+ char *old_primary_conninfo = pstrdup(PrimaryConnInfo);
+ char *old_primary_slotname = pstrdup(PrimarySlotName);
+ bool old_hot_standby_feedback = hot_standby_feedback;
+ bool conninfo_changed;
+ bool primary_slotname_changed;
+
+ ConfigReloadPending = false;
+ ProcessConfigFile(PGC_SIGHUP);
+
+ conninfo_changed = strcmp(old_primary_conninfo, PrimaryConnInfo) != 0;
+ primary_slotname_changed = strcmp(old_primary_slotname, PrimarySlotName) != 0;
+
+ if (conninfo_changed ||
+ primary_slotname_changed ||
+ (old_hot_standby_feedback != hot_standby_feedback))
+ {
+ ereport(LOG,
+ errmsg("slot sync worker will restart because of a parameter change"));
+
+ /* The exit code 1 will make postmaster restart this worker */
+ proc_exit(1);
+ }
+
+ pfree(old_primary_conninfo);
+ pfree(old_primary_slotname);
+}
+
+/*
+ * Interrupt handler for main loop of slot sync worker.
+ */
+static void
+ProcessSlotSyncInterrupts(WalReceiverConn *wrconn)
+{
+ CHECK_FOR_INTERRUPTS();
+
+ if (ShutdownRequestPending)
+ {
+ walrcv_disconnect(wrconn);
+ ereport(LOG,
+ errmsg("replication slot sync worker is shutting down on receiving SIGINT"));
+ proc_exit(0);
+ }
+
+ if (ConfigReloadPending)
+ slotsync_reread_config();
+}
+
+/*
+ * Cleanup function for slotsync worker.
+ *
+ * Called on slotsync worker exit.
+ */
+static void
+slotsync_worker_onexit(int code, Datum arg)
+{
+ SpinLockAcquire(&SlotSyncWorker->mutex);
+ SlotSyncWorker->pid = InvalidPid;
+ SpinLockRelease(&SlotSyncWorker->mutex);
+}
+
+/*
+ * Sleep for long enough that we believe it's likely that the slots on primary
+ * get updated.
+ *
+ * If there is no slot activity the wait time between sync-cycles will double
+ * (to a maximum of 30s). If there is some slot activity the wait time between
+ * sync-cycles is reset to the minimum (200ms).
+ */
+static void
+wait_for_slot_activity(bool some_slot_updated, bool am_cascading_standby)
+{
+ int rc;
+
+ if (am_cascading_standby)
+ {
+ /*
+ * Slot synchronization is currently not supported on cascading
+ * standby. So if we are on the cascading standby, we will skip the
+ * sync and take a longer nap before we check again whether we are
+ * still cascading standby or not.
+ */
+ sleep_ms = MAX_WORKER_NAPTIME_MS;
+ }
+ else if (!some_slot_updated)
+ {
+ /*
+ * No slots were updated, so double the sleep time, but not beyond the
+ * maximum allowable value.
+ */
+ sleep_ms = Min(sleep_ms * 2, MAX_WORKER_NAPTIME_MS);
+ }
+ else
+ {
+ /*
+ * Some slots were updated since the last sleep, so reset the sleep
+ * time.
+ */
+ sleep_ms = MIN_WORKER_NAPTIME_MS;
+ }
+
+ rc = WaitLatch(MyLatch,
+ WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
+ sleep_ms,
+ WAIT_EVENT_REPL_SLOTSYNC_MAIN);
+
+ if (rc & WL_LATCH_SET)
+ ResetLatch(MyLatch);
+}
+
+/*
+ * The main loop of our worker process.
+ *
+ * It connects to the primary server, fetches logical failover slots
+ * information periodically in order to create and sync the slots.
+ */
+void
+ReplSlotSyncWorkerMain(Datum main_arg)
+{
+ WalReceiverConn *wrconn = NULL;
+ char *dbname;
+ bool am_cascading_standby;
+ char *err;
+
+ ereport(LOG, errmsg("replication slot sync worker started"));
+
+ on_shmem_exit(slotsync_worker_onexit, (Datum) 0);
+
+ SpinLockAcquire(&SlotSyncWorker->mutex);
+
+ Assert(SlotSyncWorker->pid == InvalidPid);
+
+ /*
+ * Startup process signaled the slot sync worker to stop, so if meanwhile
+ * postmaster ended up starting the worker again, exit.
+ */
+ if (SlotSyncWorker->stopSignaled)
+ {
+ SpinLockRelease(&SlotSyncWorker->mutex);
+ proc_exit(0);
+ }
+
+ /* Advertise our PID so that the startup process can kill us on promotion */
+ SlotSyncWorker->pid = MyProcPid;
+
+ SpinLockRelease(&SlotSyncWorker->mutex);
+
+ /* Setup signal handling */
+ pqsignal(SIGHUP, SignalHandlerForConfigReload);
+ pqsignal(SIGINT, SignalHandlerForShutdownRequest);
+ pqsignal(SIGTERM, die);
+ BackgroundWorkerUnblockSignals();
+
+ /* Load the libpq-specific functions */
+ load_file("libpqwalreceiver", false);
+
+ dbname = validate_parameters_and_get_dbname();
+
+ /*
+ * Connect to the database specified by user in primary_conninfo. We need
+ * a database connection for walrcv_exec to work. Please see comments atop
+ * libpqrcv_exec.
+ */
+ BackgroundWorkerInitializeConnection(dbname, NULL, 0);
+
+ /*
+ * Establish the connection to the primary server for slots
+ * synchronization.
+ */
+ wrconn = walrcv_connect(PrimaryConnInfo, true, false,
+ cluster_name[0] ? cluster_name : "slotsyncworker",
+ &err);
+ if (!wrconn)
+ ereport(ERROR,
+ errcode(ERRCODE_CONNECTION_FAILURE),
+ errmsg("could not connect to the primary server: %s", err));
+
+ /*
+ * Using the specified primary server connection, check whether we are
+ * cascading standby and validates primary_slot_name for
+ * non-cascading-standbys.
+ */
+ check_primary_info(wrconn, &am_cascading_standby);
+
+ /* Main wait loop */
+ for (;;)
+ {
+ bool some_slot_updated = false;
+
+ ProcessSlotSyncInterrupts(wrconn);
+
+ if (!am_cascading_standby)
+ some_slot_updated = synchronize_slots(wrconn);
+
+ wait_for_slot_activity(some_slot_updated, am_cascading_standby);
+
+ /*
+ * If the standby was promoted then what was previously a cascading
+ * standby might no longer be one, so recheck each time.
+ */
+ if (am_cascading_standby)
+ check_primary_info(wrconn, &am_cascading_standby);
+ }
+
+ /*
+ * The slot sync worker can not get here because it will only stop when it
+ * receives a SIGINT from the startup process, or when there is an error.
+ */
+ Assert(false);
+}
+
+/*
+ * Is current process the slot sync worker?
+ */
+bool
+IsLogicalSlotSyncWorker(void)
+{
+ return SlotSyncWorker->pid == MyProcPid;
+}
+
+/*
+ * Shut down the slot sync worker.
+ */
+void
+ShutDownSlotSync(void)
+{
+ SpinLockAcquire(&SlotSyncWorker->mutex);
+
+ SlotSyncWorker->stopSignaled = true;
+
+ if (SlotSyncWorker->pid == InvalidPid)
+ {
+ SpinLockRelease(&SlotSyncWorker->mutex);
+ return;
+ }
+ SpinLockRelease(&SlotSyncWorker->mutex);
+
+ kill(SlotSyncWorker->pid, SIGINT);
+
+ /* Wait for it to die */
+ for (;;)
+ {
+ int rc;
+
+ /* Wait a bit, we don't expect to have to wait long */
+ rc = WaitLatch(MyLatch,
+ WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
+ 10L, WAIT_EVENT_BGWORKER_SHUTDOWN);
+
+ if (rc & WL_LATCH_SET)
+ {
+ ResetLatch(MyLatch);
+ CHECK_FOR_INTERRUPTS();
+ }
+
+ SpinLockAcquire(&SlotSyncWorker->mutex);
+
+ /* Is it gone? */
+ if (SlotSyncWorker->pid == InvalidPid)
+ break;
+
+ SpinLockRelease(&SlotSyncWorker->mutex);
+ }
+
+ SpinLockRelease(&SlotSyncWorker->mutex);
+}
+
+/*
+ * Allocate and initialize slot sync worker shared memory
+ */
+void
+SlotSyncWorkerShmemInit(void)
+{
+ Size size;
+ bool found;
+
+ size = sizeof(SlotSyncWorkerCtxStruct);
+ size = MAXALIGN(size);
+
+ SlotSyncWorker = (SlotSyncWorkerCtxStruct *)
+ ShmemInitStruct("Slot Sync Worker Data", size, &found);
+
+ if (!found)
+ {
+ memset(SlotSyncWorker, 0, size);
+ SlotSyncWorker->pid = InvalidPid;
+ SpinLockInit(&SlotSyncWorker->mutex);
+ }
+}
+
+/*
+ * Register the background worker for slots synchronization provided
+ * enable_syncslot is ON.
+ */
+void
+SlotSyncWorkerRegister(void)
+{
+ BackgroundWorker bgw;
+
+ if (!enable_syncslot)
+ {
+ ereport(LOG,
+ errmsg("skipping slot synchronization"),
+ errdetail("\"enable_syncslot\" is disabled."));
+ return;
+ }
+
+ memset(&bgw, 0, sizeof(bgw));
+
+ /* We need database connection which needs shared-memory access as well */
+ bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
+ BGWORKER_BACKEND_DATABASE_CONNECTION;
+
+ /* Start as soon as a consistent state has been reached in a hot standby */
+ bgw.bgw_start_time = BgWorkerStart_ConsistentState_HotStandby;
+
+ snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
+ snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ReplSlotSyncWorkerMain");
+ snprintf(bgw.bgw_name, BGW_MAXLEN,
+ "replication slot sync worker");
+ snprintf(bgw.bgw_type, BGW_MAXLEN,
+ "slot sync worker");
+
+ bgw.bgw_restart_time = BGW_DEFAULT_RESTART_INTERVAL;
+ bgw.bgw_notify_pid = 0;
+ bgw.bgw_main_arg = (Datum) 0;
+
+ RegisterBackgroundWorker(&bgw);
+}
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index f2781d0455..f07147a68a 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -47,6 +47,7 @@
#include "miscadmin.h"
#include "pgstat.h"
#include "replication/slot.h"
+#include "replication/walsender.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/proc.h"
@@ -103,7 +104,6 @@ int max_replication_slots = 10; /* the maximum number of replication
* slots */
static void ReplicationSlotShmemExit(int code, Datum arg);
-static void ReplicationSlotDropAcquired(void);
static void ReplicationSlotDropPtr(ReplicationSlot *slot);
/* internal persistency functions */
@@ -250,11 +250,12 @@ ReplicationSlotValidateName(const char *name, int elevel)
* user will only get commit prepared.
* failover: If enabled, allows the slot to be synced to standbys so
* that logical replication can be resumed after failover.
+ * synced: True if the slot is created by a slotsync worker.
*/
void
ReplicationSlotCreate(const char *name, bool db_specific,
ReplicationSlotPersistency persistency,
- bool two_phase, bool failover)
+ bool two_phase, bool failover, bool synced)
{
ReplicationSlot *slot = NULL;
int i;
@@ -263,6 +264,16 @@ ReplicationSlotCreate(const char *name, bool db_specific,
ReplicationSlotValidateName(name, ERROR);
+ /*
+ * Do not allow users to create the slots with failover enabled on the
+ * standby as we do not support sync to the cascading standby.
+ */
+ if (RecoveryInProgress() && failover)
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot enable failover for a replication slot"
+ " created on the standby"));
+
/*
* If some other backend ran this code concurrently with us, we'd likely
* both allocate the same slot, and that would be bad. We'd also be at
@@ -315,6 +326,7 @@ ReplicationSlotCreate(const char *name, bool db_specific,
slot->data.two_phase = two_phase;
slot->data.two_phase_at = InvalidXLogRecPtr;
slot->data.failover = failover;
+ slot->data.synced = synced;
/* and then data only present in shared memory */
slot->just_dirtied = false;
@@ -680,6 +692,16 @@ ReplicationSlotDrop(const char *name, bool nowait)
ReplicationSlotAcquire(name, nowait);
+ /*
+ * Do not allow users to drop the slots which are currently being synced
+ * from the primary to the standby.
+ */
+ if (RecoveryInProgress() && MyReplicationSlot->data.synced)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot drop replication slot \"%s\"", name),
+ errdetail("This slot is being synced from the primary server."));
+
ReplicationSlotDropAcquired();
}
@@ -699,6 +721,29 @@ ReplicationSlotAlter(const char *name, bool failover)
errmsg("cannot use %s with a physical replication slot",
"ALTER_REPLICATION_SLOT"));
+ if (RecoveryInProgress())
+ {
+ /*
+ * Do not allow users to alter the slots which are currently being
+ * synced from the primary to the standby.
+ */
+ if (MyReplicationSlot->data.synced)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter replication slot \"%s\"", name),
+ errdetail("This slot is being synced from the primary server."));
+
+ /*
+ * Do not allow users to alter slots to enable failover on the standby
+ * as we do not support sync to the cascading standby.
+ */
+ if (failover)
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot enable failover for a replication slot"
+ " on the standby"));
+ }
+
SpinLockAcquire(&MyReplicationSlot->mutex);
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
@@ -711,7 +756,7 @@ ReplicationSlotAlter(const char *name, bool failover)
/*
* Permanently drop the currently acquired replication slot.
*/
-static void
+void
ReplicationSlotDropAcquired(void)
{
ReplicationSlot *slot = MyReplicationSlot;
@@ -867,8 +912,8 @@ ReplicationSlotMarkDirty(void)
}
/*
- * Convert a slot that's marked as RS_EPHEMERAL to a RS_PERSISTENT slot,
- * guaranteeing it will be there after an eventual crash.
+ * Convert a slot that's marked as RS_EPHEMERAL or RS_TEMPORARY to a
+ * RS_PERSISTENT slot, guaranteeing it will be there after an eventual crash.
*/
void
ReplicationSlotPersist(void)
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index eb685089b3..843ae8cd68 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -43,7 +43,7 @@ create_physical_replication_slot(char *name, bool immediately_reserve,
/* acquire replication slot, this will check for conflicting names */
ReplicationSlotCreate(name, false,
temporary ? RS_TEMPORARY : RS_PERSISTENT, false,
- false);
+ false, false /* synced */ );
if (immediately_reserve)
{
@@ -136,7 +136,7 @@ create_logical_replication_slot(char *name, char *plugin,
*/
ReplicationSlotCreate(name, true,
temporary ? RS_TEMPORARY : RS_EPHEMERAL, two_phase,
- failover);
+ failover, false /* synced */ );
/*
* Create logical decoding context to find start point or, if we don't
@@ -237,7 +237,7 @@ pg_drop_replication_slot(PG_FUNCTION_ARGS)
Datum
pg_get_replication_slots(PG_FUNCTION_ARGS)
{
-#define PG_GET_REPLICATION_SLOTS_COLS 16
+#define PG_GET_REPLICATION_SLOTS_COLS 17
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
XLogRecPtr currlsn;
int slotno;
@@ -418,21 +418,23 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
break;
case RS_INVAL_WAL_REMOVED:
- values[i++] = CStringGetTextDatum("wal_removed");
+ values[i++] = CStringGetTextDatum(SLOT_INVAL_WAL_REMOVED_TEXT);
break;
case RS_INVAL_HORIZON:
- values[i++] = CStringGetTextDatum("rows_removed");
+ values[i++] = CStringGetTextDatum(SLOT_INVAL_HORIZON_TEXT);
break;
case RS_INVAL_WAL_LEVEL:
- values[i++] = CStringGetTextDatum("wal_level_insufficient");
+ values[i++] = CStringGetTextDatum(SLOT_INVAL_WAL_LEVEL_TEXT);
break;
}
}
values[i++] = BoolGetDatum(slot_contents.data.failover);
+ values[i++] = BoolGetDatum(slot_contents.data.synced);
+
Assert(i == PG_GET_REPLICATION_SLOTS_COLS);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
@@ -700,7 +702,6 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
XLogRecPtr src_restart_lsn;
bool src_islogical;
bool temporary;
- bool failover;
char *plugin;
Datum values[2];
bool nulls[2];
@@ -756,7 +757,6 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
src_islogical = SlotIsLogical(&first_slot_contents);
src_restart_lsn = first_slot_contents.data.restart_lsn;
temporary = (first_slot_contents.data.persistency == RS_TEMPORARY);
- failover = first_slot_contents.data.failover;
plugin = logical_slot ? NameStr(first_slot_contents.data.plugin) : NULL;
/* Check type of replication slot */
@@ -791,12 +791,20 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
* We must not try to read WAL, since we haven't reserved it yet --
* hence pass find_startpoint false. confirmed_flush will be set
* below, by copying from the source slot.
+ *
+ * To avoid potential issues with the slotsync worker when the
+ * restart_lsn of a replication slot goes backwards, we set the
+ * failover option to false here. This situation occurs when a slot on
+ * the primary server is dropped and immediately replaced with a new
+ * slot of the same name, created by copying from another existing
+ * slot. However, the slotsync worker will only observe the restart_lsn
+ * of the same slot going backwards.
*/
create_logical_replication_slot(NameStr(*dst_name),
plugin,
temporary,
false,
- failover,
+ false,
src_restart_lsn,
false);
}
diff --git a/src/backend/replication/walreceiverfuncs.c b/src/backend/replication/walreceiverfuncs.c
index 73a7d8f96c..d420a833cd 100644
--- a/src/backend/replication/walreceiverfuncs.c
+++ b/src/backend/replication/walreceiverfuncs.c
@@ -345,6 +345,22 @@ GetWalRcvFlushRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI)
return recptr;
}
+/*
+ * Returns the latest reported end of WAL on the sender
+ */
+XLogRecPtr
+GetWalRcvLatestWalEnd()
+{
+ WalRcvData *walrcv = WalRcv;
+ XLogRecPtr recptr;
+
+ SpinLockAcquire(&walrcv->mutex);
+ recptr = walrcv->latestWalEnd;
+ SpinLockRelease(&walrcv->mutex);
+
+ return recptr;
+}
+
/*
* Returns the last+1 byte position that walreceiver has written.
* This returns a recently written value without taking a lock.
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 77c8baa32a..f753aed345 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -72,6 +72,7 @@
#include "postmaster/interrupt.h"
#include "replication/decode.h"
#include "replication/logical.h"
+#include "replication/logicalworker.h"
#include "replication/slot.h"
#include "replication/snapbuild.h"
#include "replication/syncrep.h"
@@ -243,7 +244,6 @@ static void WalSndShutdown(void) pg_attribute_noreturn();
static void XLogSendPhysical(void);
static void XLogSendLogical(void);
static void WalSndDone(WalSndSendDataCallback send_data);
-static XLogRecPtr GetStandbyFlushRecPtr(TimeLineID *tli);
static void IdentifySystem(void);
static void UploadManifest(void);
static bool HandleUploadManifestPacket(StringInfo buf, off_t *offset,
@@ -1224,7 +1224,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
{
ReplicationSlotCreate(cmd->slotname, false,
cmd->temporary ? RS_TEMPORARY : RS_PERSISTENT,
- false, false);
+ false, false, false /* synced */ );
if (reserve_wal)
{
@@ -1255,7 +1255,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
*/
ReplicationSlotCreate(cmd->slotname, true,
cmd->temporary ? RS_TEMPORARY : RS_EPHEMERAL,
- two_phase, failover);
+ two_phase, failover, false /* synced */ );
/*
* Do options check early so that we can bail before calling the
@@ -3375,14 +3375,17 @@ WalSndDone(WalSndSendDataCallback send_data)
}
/*
- * Returns the latest point in WAL that has been safely flushed to disk, and
- * can be sent to the standby. This should only be called when in recovery,
- * ie. we're streaming to a cascaded standby.
+ * Returns the latest point in WAL that has been safely flushed to disk.
+ * This should only be called when in recovery.
+ *
+ * This is called either by cascading walsender to find WAL postion to
+ * be sent to a cascaded standby or by a slot sync worker to validate
+ * remote slot's lsn before syncing it locally.
*
* As a side-effect, *tli is updated to the TLI of the last
* replayed WAL record.
*/
-static XLogRecPtr
+XLogRecPtr
GetStandbyFlushRecPtr(TimeLineID *tli)
{
XLogRecPtr replayPtr;
@@ -3391,6 +3394,8 @@ GetStandbyFlushRecPtr(TimeLineID *tli)
TimeLineID receiveTLI;
XLogRecPtr result;
+ Assert(am_cascading_walsender || IsLogicalSlotSyncWorker());
+
/*
* We can safely send what's already been replayed. Also, if walreceiver
* is streaming WAL from the same timeline, we can send anything that it
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 7084e18861..925ac6c942 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -38,6 +38,7 @@
#include "replication/slot.h"
#include "replication/walreceiver.h"
#include "replication/walsender.h"
+#include "replication/worker_internal.h"
#include "storage/bufmgr.h"
#include "storage/dsm.h"
#include "storage/dsm_registry.h"
@@ -347,6 +348,7 @@ CreateOrAttachShmemStructs(void)
WalSummarizerShmemInit();
PgArchShmemInit();
ApplyLauncherShmemInit();
+ SlotSyncWorkerShmemInit();
/*
* Set up other modules that need some shared memory space
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 1a34bd3715..e8c530acd9 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3286,6 +3286,17 @@ ProcessInterrupts(void)
*/
proc_exit(1);
}
+ else if (IsLogicalSlotSyncWorker())
+ {
+ elog(DEBUG1,
+ "replication slot sync worker is shutting down due to administrator command");
+
+ /*
+ * Slot sync worker can be stopped at any time. Use exit status 1
+ * so the background worker is restarted.
+ */
+ proc_exit(1);
+ }
else if (IsBackgroundWorker)
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index a5df835dd4..3e6203322a 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -53,6 +53,7 @@ LOGICAL_APPLY_MAIN "Waiting in main loop of logical replication apply process."
LOGICAL_LAUNCHER_MAIN "Waiting in main loop of logical replication launcher process."
LOGICAL_PARALLEL_APPLY_MAIN "Waiting in main loop of logical replication parallel apply process."
RECOVERY_WAL_STREAM "Waiting in main loop of startup process for WAL to arrive, during streaming recovery."
+REPL_SLOTSYNC_MAIN "Waiting in main loop of slot sync worker."
SYSLOGGER_MAIN "Waiting in main loop of syslogger process."
WAL_RECEIVER_MAIN "Waiting in main loop of WAL receiver process."
WAL_SENDER_MAIN "Waiting in main loop of WAL sender process."
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 7fe58518d7..fe044c16de 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -68,6 +68,7 @@
#include "replication/logicallauncher.h"
#include "replication/slot.h"
#include "replication/syncrep.h"
+#include "replication/worker_internal.h"
#include "storage/bufmgr.h"
#include "storage/large_object.h"
#include "storage/pg_shmem.h"
@@ -2054,6 +2055,15 @@ struct config_bool ConfigureNamesBool[] =
NULL, NULL, NULL
},
+ {
+ {"enable_syncslot", PGC_POSTMASTER, REPLICATION_STANDBY,
+ gettext_noop("Enables a physical standby to synchronize logical failover slots from the primary server."),
+ },
+ &enable_syncslot,
+ false,
+ NULL, NULL, NULL
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL, NULL
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index da10b43dac..3868694d3f 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -361,6 +361,7 @@
#wal_retrieve_retry_interval = 5s # time to wait before retrying to
# retrieve WAL after a failed attempt
#recovery_min_apply_delay = 0 # minimum delay for applying changes during recovery
+#enable_syncslot = off # enables slot synchronization on the physical standby from the primary
# - Subscribers -
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e6e4bbdfb9..10e6a1e951 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11123,9 +11123,9 @@
proname => 'pg_get_replication_slots', prorows => '10', proisstrict => 'f',
proretset => 't', provolatile => 's', prorettype => 'record',
proargtypes => '',
- proallargtypes => '{name,name,text,oid,bool,bool,int4,xid,xid,pg_lsn,pg_lsn,text,int8,bool,text,bool}',
- proargmodes => '{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
- proargnames => '{slot_name,plugin,slot_type,datoid,temporary,active,active_pid,xmin,catalog_xmin,restart_lsn,confirmed_flush_lsn,wal_status,safe_wal_size,two_phase,conflict_reason,failover}',
+ proallargtypes => '{name,name,text,oid,bool,bool,int4,xid,xid,pg_lsn,pg_lsn,text,int8,bool,text,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
+ proargnames => '{slot_name,plugin,slot_type,datoid,temporary,active,active_pid,xmin,catalog_xmin,restart_lsn,confirmed_flush_lsn,wal_status,safe_wal_size,two_phase,conflict_reason,failover,synced}',
prosrc => 'pg_get_replication_slots' },
{ oid => '3786', descr => 'set up a logical replication slot',
proname => 'pg_create_logical_replication_slot', provolatile => 'v',
diff --git a/src/include/postmaster/bgworker.h b/src/include/postmaster/bgworker.h
index 22fc49ec27..7092fc72c6 100644
--- a/src/include/postmaster/bgworker.h
+++ b/src/include/postmaster/bgworker.h
@@ -79,6 +79,7 @@ typedef enum
BgWorkerStart_PostmasterStart,
BgWorkerStart_ConsistentState,
BgWorkerStart_RecoveryFinished,
+ BgWorkerStart_ConsistentState_HotStandby,
} BgWorkerStartTime;
#define BGW_DEFAULT_RESTART_INTERVAL 60
diff --git a/src/include/replication/logicalworker.h b/src/include/replication/logicalworker.h
index a18d79d1b2..bbe04226db 100644
--- a/src/include/replication/logicalworker.h
+++ b/src/include/replication/logicalworker.h
@@ -22,6 +22,7 @@ extern void TablesyncWorkerMain(Datum main_arg);
extern bool IsLogicalWorker(void);
extern bool IsLogicalParallelApplyWorker(void);
+extern bool IsLogicalSlotSyncWorker(void);
extern void HandleParallelApplyMessageInterrupt(void);
extern void HandleParallelApplyMessages(void);
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 72ef4859ee..41f0cc35f3 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -52,6 +52,14 @@ typedef enum ReplicationSlotInvalidationCause
RS_INVAL_WAL_LEVEL,
} ReplicationSlotInvalidationCause;
+/*
+ * The possible values for 'conflict_reason' returned in
+ * pg_get_replication_slots.
+ */
+#define SLOT_INVAL_WAL_REMOVED_TEXT "wal_removed"
+#define SLOT_INVAL_HORIZON_TEXT "rows_removed"
+#define SLOT_INVAL_WAL_LEVEL_TEXT "wal_level_insufficient"
+
/*
* On-Disk data of a replication slot, preserved across restarts.
*/
@@ -112,6 +120,11 @@ typedef struct ReplicationSlotPersistentData
/* plugin name */
NameData plugin;
+ /*
+ * Was this slot synchronized from the primary server?
+ */
+ char synced;
+
/*
* Is this a failover slot (sync candidate for standbys)? Only
* relevant for logical slots on the primary server.
@@ -224,9 +237,11 @@ extern void ReplicationSlotsShmemInit(void);
/* management of individual slots */
extern void ReplicationSlotCreate(const char *name, bool db_specific,
ReplicationSlotPersistency persistency,
- bool two_phase, bool failover);
+ bool two_phase, bool failover,
+ bool synced);
extern void ReplicationSlotPersist(void);
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);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index f566a99ba1..48dc846e19 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -279,6 +279,13 @@ typedef void (*walrcv_get_senderinfo_fn) (WalReceiverConn *conn,
typedef char *(*walrcv_identify_system_fn) (WalReceiverConn *conn,
TimeLineID *primary_tli);
+/*
+ * walrcv_get_dbname_from_conninfo_fn
+ *
+ * Returns the dbid from the primary_conninfo
+ */
+typedef char *(*walrcv_get_dbname_from_conninfo_fn) (const char *conninfo);
+
/*
* walrcv_server_version_fn
*
@@ -403,6 +410,7 @@ typedef struct WalReceiverFunctionsType
walrcv_get_conninfo_fn walrcv_get_conninfo;
walrcv_get_senderinfo_fn walrcv_get_senderinfo;
walrcv_identify_system_fn walrcv_identify_system;
+ walrcv_get_dbname_from_conninfo_fn walrcv_get_dbname_from_conninfo;
walrcv_server_version_fn walrcv_server_version;
walrcv_readtimelinehistoryfile_fn walrcv_readtimelinehistoryfile;
walrcv_startstreaming_fn walrcv_startstreaming;
@@ -428,6 +436,8 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_get_senderinfo(conn, sender_host, sender_port)
#define walrcv_identify_system(conn, primary_tli) \
WalReceiverFunctions->walrcv_identify_system(conn, primary_tli)
+#define walrcv_get_dbname_from_conninfo(conninfo) \
+ WalReceiverFunctions->walrcv_get_dbname_from_conninfo(conninfo)
#define walrcv_server_version(conn) \
WalReceiverFunctions->walrcv_server_version(conn)
#define walrcv_readtimelinehistoryfile(conn, tli, filename, content, size) \
@@ -485,6 +495,7 @@ extern void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr,
bool create_temp_slot);
extern XLogRecPtr GetWalRcvFlushRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI);
extern XLogRecPtr GetWalRcvWriteRecPtr(void);
+extern XLogRecPtr GetWalRcvLatestWalEnd(void);
extern int GetReplicationApplyDelay(void);
extern int GetReplicationTransferLatency(void);
diff --git a/src/include/replication/walsender.h b/src/include/replication/walsender.h
index 1b58d50b3b..276d8913aa 100644
--- a/src/include/replication/walsender.h
+++ b/src/include/replication/walsender.h
@@ -12,6 +12,8 @@
#ifndef _WALSENDER_H
#define _WALSENDER_H
+#include "access/xlogdefs.h"
+
/*
* What to do with a snapshot in create replication slot command.
*/
@@ -45,6 +47,7 @@ extern void WalSndInitStopping(void);
extern void WalSndWaitStopping(void);
extern void HandleWalSndInitStopping(void);
extern void WalSndRqstFileReload(void);
+extern XLogRecPtr GetStandbyFlushRecPtr(TimeLineID *tli);
/*
* Remember that we want to wakeup walsenders later
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 515aefd519..2167720971 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -237,6 +237,11 @@ extern PGDLLIMPORT bool in_remote_transaction;
extern PGDLLIMPORT bool InitializingApplyWorker;
+/* Slot sync worker objects */
+extern PGDLLIMPORT char *PrimaryConnInfo;
+extern PGDLLIMPORT char *PrimarySlotName;
+extern PGDLLIMPORT bool enable_syncslot;
+
extern void logicalrep_worker_attach(int slot);
extern LogicalRepWorker *logicalrep_worker_find(Oid subid, Oid relid,
bool only_running);
@@ -325,6 +330,11 @@ extern void pa_decr_and_wait_stream_block(void);
extern void pa_xact_finish(ParallelApplyWorkerInfo *winfo,
XLogRecPtr remote_lsn);
+extern void ReplSlotSyncWorkerMain(Datum main_arg);
+extern void SlotSyncWorkerRegister(void);
+extern void ShutDownSlotSync(void);
+extern void SlotSyncWorkerShmemInit(void);
+
#define isParallelApplyWorker(worker) ((worker)->in_use && \
(worker)->type == WORKERTYPE_PARALLEL_APPLY)
#define isTablesyncWorker(worker) ((worker)->in_use && \
diff --git a/src/test/recovery/t/050_standby_failover_slots_sync.pl b/src/test/recovery/t/050_standby_failover_slots_sync.pl
index 646293c39e..1055573cde 100644
--- a/src/test/recovery/t/050_standby_failover_slots_sync.pl
+++ b/src/test/recovery/t/050_standby_failover_slots_sync.pl
@@ -84,6 +84,170 @@ is( $publisher->safe_psql(
"t",
'logical slot has failover true on the publisher');
-$subscriber1->safe_psql('postgres', "DROP SUBSCRIPTION regress_mysub1");
+$subscriber1->safe_psql('postgres', "ALTER SUBSCRIPTION regress_mysub1 ENABLE");
+
+##################################################
+# Test logical failover slots on the standby
+# Configure standby1 to replicate and synchronize logical slots configured
+# for failover on the primary
+#
+# failover slot lsub1_slot->| ----> subscriber1 (connected via logical replication)
+# primary ---> |
+# physical slot sb1_slot--->| ----> standby1 (connected via streaming replication)
+# | lsub1_slot(synced_slot)
+##################################################
+
+my $primary = $publisher;
+my $backup_name = 'backup';
+$primary->backup($backup_name);
+
+# Create a standby
+my $standby1 = PostgreSQL::Test::Cluster->new('standby1');
+$standby1->init_from_backup(
+ $primary, $backup_name,
+ has_streaming => 1,
+ has_restoring => 1);
+
+my $connstr_1 = $primary->connstr;
+$standby1->append_conf(
+ 'postgresql.conf', qq(
+enable_syncslot = true
+hot_standby_feedback = on
+primary_slot_name = 'sb1_slot'
+primary_conninfo = '$connstr_1 dbname=postgres'
+));
+
+$primary->psql('postgres',
+ q{SELECT pg_create_physical_replication_slot('sb1_slot');});
+
+my $standby1_conninfo = $standby1->connstr . ' dbname=postgres';
+my $offset = -s $standby1->logfile;
+
+# Start the standby so that slot syncing can begin
+$standby1->start;
+
+# Generate a log to trigger the walsender to send messages to the walreceiver
+# which will update WalRcv->latestWalEnd to a valid number.
+$primary->safe_psql('postgres', "SELECT pg_log_standby_snapshot();");
+
+# Wait for the standby to finish sync
+$standby1->wait_for_log(
+ qr/LOG: ( [A-Z0-9]+:)? newly created slot \"lsub1_slot\" is sync-ready now/,
+ $offset);
+
+# Confirm that the logical failover slot is created on the standby and is
+# flagged as 'synced'
+is($standby1->safe_psql('postgres',
+ q{SELECT synced FROM pg_replication_slots WHERE slot_name = 'lsub1_slot';}),
+ "t",
+ 'logical slot has synced as true on standby');
+
+##################################################
+# Test to confirm that restart_lsn and confirmed_flush_lsn of the logical slot
+# on the primary is synced to the standby
+##################################################
+
+# Insert data on the primary
+$primary->safe_psql(
+ 'postgres', qq[
+ CREATE TABLE tab_int (a int PRIMARY KEY);
+ INSERT INTO tab_int SELECT generate_series(1, 10);
+]);
+
+# Subscribe to the new table data and wait for it to arrive
+$subscriber1->safe_psql(
+ 'postgres', qq[
+ CREATE TABLE tab_int (a int PRIMARY KEY);
+ ALTER SUBSCRIPTION regress_mysub1 REFRESH PUBLICATION;
+]);
+
+$subscriber1->wait_for_subscription_sync;
+
+# Do not allow any further advancement of the restart_lsn and
+# confirmed_flush_lsn for the lsub1_slot.
+$subscriber1->safe_psql('postgres', "ALTER SUBSCRIPTION regress_mysub1 DISABLE");
+
+# Wait for the replication slot to become inactive on the publisher
+$primary->poll_query_until(
+ 'postgres',
+ "SELECT COUNT(*) FROM pg_catalog.pg_replication_slots WHERE slot_name = 'lsub1_slot' AND active='f'",
+ 1);
+
+# Get the restart_lsn for the logical slot lsub1_slot on the primary
+my $primary_restart_lsn = $primary->safe_psql('postgres',
+ "SELECT restart_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot';");
+
+# Get the confirmed_flush_lsn for the logical slot lsub1_slot on the primary
+my $primary_flush_lsn = $primary->safe_psql('postgres',
+ "SELECT confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot';");
+
+# Confirm that restart_lsn and of confirmed_flush_lsn lsub1_slot slot are synced
+# to the standby
+ok( $standby1->poll_query_until(
+ 'postgres',
+ "SELECT '$primary_restart_lsn' = restart_lsn AND '$primary_flush_lsn' = confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot';"),
+ 'restart_lsn and confirmed_flush_lsn of slot lsub1_slot synced to standby');
+
+##################################################
+# Test that a synchronized slot can not be decoded, altered or dropped by the user
+##################################################
+
+# Disable hot_standby_feedback temporarily to stop slot sync worker otherwise
+# the concerned testing scenarios here may be interrupted by different error:
+# 'ERROR: replication slot is active for PID ..'
+$standby1->safe_psql('postgres', 'ALTER SYSTEM SET hot_standby_feedback = off;');
+$standby1->restart;
+
+# Attempting to perform logical decoding on a synced slot should result in an error
+my ($result, $stdout, $stderr) = $standby1->psql('postgres',
+ "select * from pg_logical_slot_get_changes('lsub1_slot',NULL,NULL);");
+ok($stderr =~ /ERROR: cannot use replication slot "lsub1_slot" for logical decoding/,
+ "logical decoding is not allowed on synced slot");
+
+# Attempting to alter a synced slot should result in an error
+($result, $stdout, $stderr) = $standby1->psql(
+ 'postgres',
+ qq[ALTER_REPLICATION_SLOT lsub1_slot (failover);],
+ replication => 'database');
+ok($stderr =~ /ERROR: cannot alter replication slot "lsub1_slot"/,
+ "synced slot on standby cannot be altered");
+
+# Attempting to drop a synced slot should result in an error
+($result, $stdout, $stderr) = $standby1->psql('postgres',
+ "SELECT pg_drop_replication_slot('lsub1_slot');");
+ok($stderr =~ /ERROR: cannot drop replication slot "lsub1_slot"/,
+ "synced slot on standby cannot be dropped");
+
+# Enable hot_standby_feedback and restart standby
+$standby1->safe_psql('postgres', 'ALTER SYSTEM SET hot_standby_feedback = on;');
+$standby1->restart;
+
+##################################################
+# Promote the standby1 to primary. Confirm that:
+# a) the slot 'lsub1_slot' is retained on the new primary
+# b) logical replication for regress_mysub1 is resumed successfully after failover
+##################################################
+$standby1->promote;
+
+# Update subscription with the new primary's connection info
+$subscriber1->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_mysub1 CONNECTION '$standby1_conninfo';
+ ALTER SUBSCRIPTION regress_mysub1 ENABLE; ");
+
+# Confirm the synced slot 'lsub1_slot' is retained on the new primary
+is($standby1->safe_psql('postgres',
+ q{SELECT slot_name FROM pg_replication_slots WHERE slot_name = 'lsub1_slot';}),
+ 'lsub1_slot',
+ 'synced slot retained on the new primary');
+
+# Insert data on the new primary
+$standby1->safe_psql('postgres',
+ "INSERT INTO tab_int SELECT generate_series(11, 20);");
+$standby1->wait_for_catchup('regress_mysub1');
+
+# Confirm that data in tab_int replicated on the subscriber
+is( $subscriber1->safe_psql('postgres', q{SELECT count(*) FROM tab_int;}),
+ "20",
+ 'data replicated from the new primary');
done_testing();
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 57884d3fec..cb43ba1c3f 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1474,8 +1474,9 @@ pg_replication_slots| SELECT l.slot_name,
l.safe_wal_size,
l.two_phase,
l.conflict_reason,
- l.failover
- FROM (pg_get_replication_slots() l(slot_name, plugin, slot_type, datoid, temporary, active, active_pid, xmin, catalog_xmin, restart_lsn, confirmed_flush_lsn, wal_status, safe_wal_size, two_phase, conflict_reason, failover)
+ l.failover,
+ l.synced
+ FROM (pg_get_replication_slots() l(slot_name, plugin, slot_type, datoid, temporary, active, active_pid, xmin, catalog_xmin, restart_lsn, confirmed_flush_lsn, wal_status, safe_wal_size, two_phase, conflict_reason, failover, synced)
LEFT JOIN pg_database d ON ((l.datoid = d.oid)));
pg_roles| SELECT pg_authid.rolname,
pg_authid.rolsuper,
diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out
index 9be7aca2b8..fae059d389 100644
--- a/src/test/regress/expected/sysviews.out
+++ b/src/test/regress/expected/sysviews.out
@@ -133,8 +133,9 @@ select name, setting from pg_settings where name like 'enable%';
enable_self_join_removal | on
enable_seqscan | on
enable_sort | on
+ enable_syncslot | off
enable_tidscan | on
-(23 rows)
+(24 rows)
-- There are always wait event descriptions for various types.
select type, count(*) > 0 as ok FROM pg_wait_events
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 513c7702ff..d527bf918b 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2325,6 +2325,7 @@ RelocationBufferInfo
RelptrFreePageBtree
RelptrFreePageManager
RelptrFreePageSpanLeader
+RemoteSlot
RenameStmt
ReopenPtrType
ReorderBuffer
@@ -2585,6 +2586,7 @@ SlabBlock
SlabContext
SlabSlot
SlotNumber
+SlotSyncWorkerCtxStruct
SlruCtl
SlruCtlData
SlruErrorCause
--
2.30.0.windows.2
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Subject: RE: Synchronizing slots from primary to standby
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