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Remove promote_trigger_file.
Previously, an idle startup (recovery) process would wake up every 5 seconds to have a chance to poll for promote_trigger_file, even if that GUC was not configured. That promotion triggering mechanism was effectively superseded by pg_ctl promote and pg_promote() a long time ago. There probably aren't many users left and it's very easy to change to the modern mechanisms, so we agreed to remove the feature. This is part of a campaign to reduce wakeups on idle systems. Author: Simon Riggs <simon.riggs@enterprisedb.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Ian Lawrence Barwick <barwick@gmail.com> Discussion: https://postgr.es/m/CANbhV-FsjnzVOQGBpQ589%3DnWuL1Ex0Ykn74Nh1hEjp2usZSR5g%40mail.gmail.com
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‎doc/src/sgml/appendix-obsolete-recovery-config.sgml

Lines changed: 5 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -34,14 +34,11 @@
3434
</para>
3535

3636
<para>
37-
The
38-
<literal>trigger_file</literal>
39-
<indexterm>
40-
<primary>trigger_file</primary>
41-
<see>promote_trigger_file</see>
42-
</indexterm>
43-
setting has been renamed to
44-
<xref linkend="guc-promote-trigger-file"/>.
37+
PostgreSQL 15 and below had a setting
38+
<literal>promote_trigger_file</literal>, or
39+
<literal>trigger_file</literal> before 12.
40+
Use <command>pg_ctl promote</command> or call
41+
<function>pg_promote()</function> to promote a standby instead.
4542
</para>
4643

4744
<para>

‎doc/src/sgml/config.sgml

Lines changed: 0 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -4610,24 +4610,6 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
46104610
</listitem>
46114611
</varlistentry>
46124612

4613-
<varlistentry id="guc-promote-trigger-file" xreflabel="promote_trigger_file">
4614-
<term><varname>promote_trigger_file</varname> (<type>string</type>)
4615-
<indexterm>
4616-
<primary><varname>promote_trigger_file</varname> configuration parameter</primary>
4617-
</indexterm>
4618-
</term>
4619-
<listitem>
4620-
<para>
4621-
Specifies a trigger file whose presence ends recovery in the
4622-
standby. Even if this value is not set, you can still promote
4623-
the standby using <command>pg_ctl promote</command> or calling
4624-
<function>pg_promote()</function>.
4625-
This parameter can only be set in the <filename>postgresql.conf</filename>
4626-
file or on the server command line.
4627-
</para>
4628-
</listitem>
4629-
</varlistentry>
4630-
46314613
<varlistentry id="guc-hot-standby" xreflabel="hot_standby">
46324614
<term><varname>hot_standby</varname> (<type>boolean</type>)
46334615
<indexterm>

‎doc/src/sgml/high-availability.sgml

Lines changed: 8 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -653,11 +653,10 @@ protocol to make nodes agree on a serializable transactional order.
653653

654654
<para>
655655
Standby mode is exited and the server switches to normal operation
656-
when <command>pg_ctl promote</command> is run,
657-
<function>pg_promote()</function> is called, or a trigger file is found
658-
(<varname>promote_trigger_file</varname>). Before failover,
659-
any WAL immediately available in the archive or in <filename>pg_wal</filename> will be
660-
restored, but no attempt is made to connect to the primary.
656+
when <command>pg_ctl promote</command> is run, or
657+
<function>pg_promote()</function> is called. Before failover,
658+
any WAL immediately available in the archive or in <filename>pg_wal</filename>
659+
will be restored, but no attempt is made to connect to the primary.
661660
</para>
662661
</sect2>
663662

@@ -1483,15 +1482,10 @@ synchronous_standby_names = 'ANY 2 (s1, s2, s3)'
14831482

14841483
<para>
14851484
To trigger failover of a log-shipping standby server, run
1486-
<command>pg_ctl promote</command>, call <function>pg_promote()</function>,
1487-
or create a trigger file with the file name and path specified by the
1488-
<varname>promote_trigger_file</varname>. If you're planning to use
1489-
<command>pg_ctl promote</command> or to call
1490-
<function>pg_promote()</function> to fail over,
1491-
<varname>promote_trigger_file</varname> is not required. If you're
1492-
setting up the reporting servers that are only used to offload read-only
1493-
queries from the primary, not for high availability purposes, you don't
1494-
need to promote it.
1485+
<command>pg_ctl promote</command> or call <function>pg_promote()</function>.
1486+
If you're setting up reporting servers that are only used to offload
1487+
read-only queries from the primary, not for high availability purposes,
1488+
you don't need to promote.
14951489
</para>
14961490
</sect1>
14971491

‎src/backend/access/transam/xlogrecovery.c

Lines changed: 16 additions & 41 deletions
Original file line numberDiff line numberDiff line change
@@ -95,7 +95,6 @@ int recovery_min_apply_delay = 0;
9595
/* options formerly taken from recovery.conf for XLOG streaming */
9696
char *PrimaryConnInfo = NULL;
9797
char *PrimarySlotName = NULL;
98-
char *PromoteTriggerFile = NULL;
9998
bool wal_receiver_create_temp_slot = false;
10099

101100
/*
@@ -318,8 +317,8 @@ typedef struct XLogRecoveryCtlData
318317

319318
/*
320319
* recoveryWakeupLatch is used to wake up the startup process to continue
321-
* WAL replay, if it is waiting for WAL to arrive or failover trigger file
322-
* to appear.
320+
* WAL replay, if it is waiting for WAL to arrive or promotion to be
321+
* requested.
323322
*
324323
* Note that the startup process also uses another latch, its procLatch,
325324
* to wait for recovery conflict. If we get rid of recoveryWakeupLatch for
@@ -2906,10 +2905,7 @@ recoveryApplyDelay(XLogReaderState *record)
29062905
{
29072906
ResetLatch(&XLogRecoveryCtl->recoveryWakeupLatch);
29082907

2909-
/*
2910-
* This might change recovery_min_apply_delay or the trigger file's
2911-
* location.
2912-
*/
2908+
/* This might change recovery_min_apply_delay. */
29132909
HandleStartupProcInterrupts();
29142910

29152911
if (CheckForStandbyTrigger())
@@ -3155,8 +3151,8 @@ ReadRecord(XLogPrefetcher *xlogprefetcher, int emode,
31553151
* as for waiting for the requested WAL record to arrive in standby mode.
31563152
*
31573153
* 'emode' specifies the log level used for reporting "file not found" or
3158-
* "end of WAL" situations in archive recovery, or in standby mode when a
3159-
* trigger file is found. If set to WARNING or below, XLogPageRead() returns
3154+
* "end of WAL" situations in archive recovery, or in standby mode when
3155+
* promotion is triggered. If set to WARNING or below, XLogPageRead() returns
31603156
* XLREAD_FAIL in those situations, on higher log levels the ereport() won't
31613157
* return.
31623158
*
@@ -3424,7 +3420,7 @@ WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess,
34243420
*
34253421
* 1. Read from either archive or pg_wal (XLOG_FROM_ARCHIVE), or just
34263422
* pg_wal (XLOG_FROM_PG_WAL)
3427-
* 2. Check trigger file
3423+
* 2. Check for promotion trigger request
34283424
* 3. Read from primary server via walreceiver (XLOG_FROM_STREAM)
34293425
* 4. Rescan timelines
34303426
* 5. Sleep wal_retrieve_retry_interval milliseconds, and loop back to 1.
@@ -3481,10 +3477,10 @@ WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess,
34813477
case XLOG_FROM_PG_WAL:
34823478

34833479
/*
3484-
* Check to see if the trigger file exists. Note that we
3485-
* do this only after failure, so when you create the
3486-
* trigger file, we still finish replaying as much as we
3487-
* can from archive and pg_wal before failover.
3480+
* Check to see if promotion is requested. Note that we do
3481+
* this only after failure, so when you promote, we still
3482+
* finish replaying as much as we can from archive and
3483+
* pg_wal before failover.
34883484
*/
34893485
if (StandbyMode && CheckForStandbyTrigger())
34903486
{
@@ -3840,14 +3836,13 @@ WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess,
38403836
XLogPrefetcherComputeStats(xlogprefetcher);
38413837

38423838
/*
3843-
* Wait for more WAL to arrive. Time out after 5 seconds
3844-
* to react to a trigger file promptly and to check if the
3845-
* WAL receiver is still active.
3839+
* Wait for more WAL to arrive, when we will be woken
3840+
* immediately by the WAL receiver.
38463841
*/
38473842
(void) WaitLatch(&XLogRecoveryCtl->recoveryWakeupLatch,
3848-
WL_LATCH_SET | WL_TIMEOUT |
3849-
WL_EXIT_ON_PM_DEATH,
3850-
5000L, WAIT_EVENT_RECOVERY_WAL_STREAM);
3843+
WL_LATCH_SET | WL_EXIT_ON_PM_DEATH,
3844+
-1L,
3845+
WAIT_EVENT_RECOVERY_WAL_STREAM);
38513846
ResetLatch(&XLogRecoveryCtl->recoveryWakeupLatch);
38523847
break;
38533848
}
@@ -4294,14 +4289,11 @@ SetPromoteIsTriggered(void)
42944289
}
42954290

42964291
/*
4297-
* Check to see whether the user-specified trigger file exists and whether a
4298-
* promote request has arrived. If either condition holds, return true.
4292+
* Check whether a promote request has arrived.
42994293
*/
43004294
static bool
43014295
CheckForStandbyTrigger(void)
43024296
{
4303-
struct stat stat_buf;
4304-
43054297
if (LocalPromoteIsTriggered)
43064298
return true;
43074299

@@ -4314,23 +4306,6 @@ CheckForStandbyTrigger(void)
43144306
return true;
43154307
}
43164308

4317-
if (PromoteTriggerFile == NULL || strcmp(PromoteTriggerFile, "") == 0)
4318-
return false;
4319-
4320-
if (stat(PromoteTriggerFile, &stat_buf) == 0)
4321-
{
4322-
ereport(LOG,
4323-
(errmsg("promote trigger file found: %s", PromoteTriggerFile)));
4324-
unlink(PromoteTriggerFile);
4325-
SetPromoteIsTriggered();
4326-
return true;
4327-
}
4328-
else if (errno != ENOENT)
4329-
ereport(ERROR,
4330-
(errcode_for_file_access(),
4331-
errmsg("could not stat promote trigger file \"%s\": %m",
4332-
PromoteTriggerFile)));
4333-
43344309
return false;
43354310
}
43364311

‎src/backend/utils/misc/guc_tables.c

Lines changed: 0 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -3819,16 +3819,6 @@ struct config_string ConfigureNamesString[] =
38193819
check_recovery_target_lsn, assign_recovery_target_lsn, NULL
38203820
},
38213821

3822-
{
3823-
{"promote_trigger_file", PGC_SIGHUP, REPLICATION_STANDBY,
3824-
gettext_noop("Specifies a file name whose presence ends recovery in the standby."),
3825-
NULL
3826-
},
3827-
&PromoteTriggerFile,
3828-
"",
3829-
NULL, NULL, NULL
3830-
},
3831-
38323822
{
38333823
{"primary_conninfo", PGC_SIGHUP, REPLICATION_STANDBY,
38343824
gettext_noop("Sets the connection string to be used to connect to the sending server."),

‎src/backend/utils/misc/postgresql.conf.sample

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -331,7 +331,6 @@
331331

332332
#primary_conninfo = '' # connection string to sending server
333333
#primary_slot_name = '' # replication slot on sending server
334-
#promote_trigger_file = '' # file name whose presence ends recovery
335334
#hot_standby = on # "off" disallows queries during recovery
336335
# (change requires restart)
337336
#max_standby_archive_delay = 30s # max delay before canceling queries

‎src/include/access/xlogrecovery.h

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -65,7 +65,6 @@ extern PGDLLIMPORT TimestampTz recoveryTargetTime;
6565
extern PGDLLIMPORT const char *recoveryTargetName;
6666
extern PGDLLIMPORT XLogRecPtr recoveryTargetLSN;
6767
extern PGDLLIMPORT RecoveryTargetType recoveryTarget;
68-
extern PGDLLIMPORT char *PromoteTriggerFile;
6968
extern PGDLLIMPORT bool wal_receiver_create_temp_slot;
7069
extern PGDLLIMPORT RecoveryTargetTimeLineGoal recoveryTargetTimeLineGoal;
7170
extern PGDLLIMPORT TimeLineID recoveryTargetTLIRequested;

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