On Thu, Dec 19, 2024, at 10:31 AM, Peter Eisentraut wrote:
> On 10.12.24 19:41, Euler Taveira wrote:
> > I'm attaching a patch that adds max_replication_origins. It basically
> > replaces
> > all of the points that refers to max_replication_slots on the subscriber. It
> > uses the same default value as max_replication_slots (10). I did nothing to
> > keep the backward compatibility. I mean has a special value (like -1) that
> > means same value as max_replication_slots. Is it worth it? (If not, it
> > should
> > be mentioned in the commit message.)
>
> I think some backward compatibility tweak like that would be useful.
> Otherwise, the net effect of this is that most people will have to do
> one more thing than before to keep their systems working. Also, all
> deployment and automation scripts would have to be updated for this.
>
This new patch includes the special value (-1) that uses max_replication_slots
instead.
--
Euler Taveira
EDB https://www.enterprisedb.com/
From 8a80eb6a8aa3cbfb2c0eb09ee3799e857729e205 Mon Sep 17 00:00:00 2001
From: Euler Taveira <eu...@eulerto.com>
Date: Tue, 3 Sep 2024 12:10:20 -0300
Subject: [PATCH v2] Separate GUC for replication origins
This feature already exists but it is provided by an existing GUC:
max_replication_slots. The new GUC (max_replication_origins) defines the
maximum number of replication origins that can be tracked
simultaneously. The max_replication_slots was used for this purpose but
it is confusing (when you are learning about logical replication) and
introduces a limitation (you cannot have a small number of replication
slots and a high number of subscriptions).
For backward compatibility, the default is -1, indicating that the value
of max_replication_slots is used instead.
---
doc/src/sgml/config.sgml | 27 ++----
doc/src/sgml/logical-replication.sgml | 6 +-
src/backend/replication/logical/launcher.c | 4 +-
src/backend/replication/logical/origin.c | 91 ++++++++++++-------
src/backend/utils/misc/guc_tables.c | 12 +++
src/backend/utils/misc/postgresql.conf.sample | 3 +
src/bin/pg_basebackup/pg_createsubscriber.c | 18 ++--
.../t/040_pg_createsubscriber.pl | 4 +-
src/bin/pg_upgrade/check.c | 14 +--
src/bin/pg_upgrade/t/004_subscription.pl | 14 +--
src/include/replication/origin.h | 3 +
11 files changed, 111 insertions(+), 85 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 8683f0bdf5..1f15d97055 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -4493,13 +4493,6 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows
to <literal>replica</literal> or higher to allow replication slots to
be used.
</para>
-
- <para>
- Note that this parameter also applies on the subscriber side, but with
- a different meaning. See <xref linkend="guc-max-replication-slots-subscriber"/>
- in <xref linkend="runtime-config-replication-subscriber"/> for more
- details.
- </para>
</listitem>
</varlistentry>
@@ -5202,10 +5195,10 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
<variablelist>
- <varlistentry id="guc-max-replication-slots-subscriber" xreflabel="max_replication_slots">
- <term><varname>max_replication_slots</varname> (<type>integer</type>)
+ <varlistentry id="guc-max-replication-origins" xreflabel="max_replication_origins">
+ <term><varname>max_replication_origins</varname> (<type>integer</type>)
<indexterm>
- <primary><varname>max_replication_slots</varname> configuration parameter</primary>
+ <primary><varname>max_replication_origins</varname> configuration parameter</primary>
<secondary>in a subscriber</secondary>
</indexterm>
</term>
@@ -5217,18 +5210,14 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
be created on the server. Setting it to a lower value than the current
number of tracked replication origins (reflected in
<link linkend="view-pg-replication-origin-status">pg_replication_origin_status</link>)
- will prevent the server from starting.
- <literal>max_replication_slots</literal> must be set to at least the
+ will prevent the server from starting. It defaults to -1, indicating
+ that the value of <xref linkend="guc-max-replication-slots"/> should be
+ used instead. This parameter can only be set at server start.
+
+ <literal>max_replication_origins</literal> must be set to at least the
number of subscriptions that will be added to the subscriber, plus some
reserve for table synchronization.
</para>
-
- <para>
- Note that this parameter also applies on a sending server, but with
- a different meaning. See <xref linkend="guc-max-replication-slots"/>
- in <xref linkend="runtime-config-replication-sender"/> for more
- details.
- </para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml
index 8290cd1a08..1c4b6586db 100644
--- a/doc/src/sgml/logical-replication.sgml
+++ b/doc/src/sgml/logical-replication.sgml
@@ -2144,9 +2144,7 @@ CONTEXT: processing remote data for replication origin "pg_16395" during "INSER
<para>
Logical replication requires several configuration options to be set. Most
- options are relevant only on one side of the replication. However,
- <varname>max_replication_slots</varname> is used on both the publisher and
- the subscriber, but it has a different meaning for each.
+ options are relevant only on one side of the replication.
</para>
<sect2 id="logical-replication-config-publisher">
@@ -2181,7 +2179,7 @@ CONTEXT: processing remote data for replication origin "pg_16395" during "INSER
<title>Subscribers</title>
<para>
- <link linkend="guc-max-replication-slots-subscriber"><varname>max_replication_slots</varname></link>
+ <link linkend="guc-max-replication-origins"><varname>max_replication_origins</varname></link>
must be set to at least the number of subscriptions that will be added to
the subscriber, plus some reserve for table synchronization.
</para>
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index a3c7adbf1a..581bdd091f 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -31,7 +31,7 @@
#include "postmaster/bgworker.h"
#include "postmaster/interrupt.h"
#include "replication/logicallauncher.h"
-#include "replication/slot.h"
+#include "replication/origin.h"
#include "replication/walreceiver.h"
#include "replication/worker_internal.h"
#include "storage/ipc.h"
@@ -325,7 +325,7 @@ logicalrep_worker_launch(LogicalRepWorkerType wtype,
subname)));
/* Report this after the initial starting message for consistency. */
- if (max_replication_slots == 0)
+ if (max_replication_origins == 0)
ereport(ERROR,
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
errmsg("cannot start logical replication workers when \"max_replication_slots\"=0")));
diff --git a/src/backend/replication/logical/origin.c b/src/backend/replication/logical/origin.c
index 1b586cb1cf..63bbcde2a6 100644
--- a/src/backend/replication/logical/origin.c
+++ b/src/backend/replication/logical/origin.c
@@ -90,6 +90,7 @@
#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
+#include "utils/guc_hooks.h"
#include "utils/pg_lsn.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
@@ -99,6 +100,9 @@
#define PG_REPLORIGIN_CHECKPOINT_FILENAME PG_LOGICAL_DIR "/replorigin_checkpoint"
#define PG_REPLORIGIN_CHECKPOINT_TMPFILE PG_REPLORIGIN_CHECKPOINT_FILENAME ".tmp"
+/* GUC variables */
+int max_replication_origins = -1;
+
/*
* Replay progress of a single remote node.
*/
@@ -151,7 +155,7 @@ typedef struct ReplicationStateCtl
{
/* Tranche to use for per-origin LWLocks */
int tranche_id;
- /* Array of length max_replication_slots */
+ /* Array of length max_replication_origins */
ReplicationState states[FLEXIBLE_ARRAY_MEMBER];
} ReplicationStateCtl;
@@ -162,10 +166,7 @@ TimestampTz replorigin_session_origin_timestamp = 0;
/*
* Base address into a shared memory array of replication states of size
- * max_replication_slots.
- *
- * XXX: Should we use a separate variable to size this rather than
- * max_replication_slots?
+ * max_replication_origins.
*/
static ReplicationState *replication_states;
@@ -186,12 +187,12 @@ static ReplicationState *session_replication_state = NULL;
#define REPLICATION_STATE_MAGIC ((uint32) 0x1257DADE)
static void
-replorigin_check_prerequisites(bool check_slots, bool recoveryOK)
+replorigin_check_prerequisites(bool check_origins, bool recoveryOK)
{
- if (check_slots && max_replication_slots == 0)
+ if (check_origins && max_replication_origins == 0)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot query or manipulate replication origin when \"max_replication_slots\" is 0")));
+ errmsg("cannot query or manipulate replication origin when \"max_replication_origins\" is 0")));
if (!recoveryOK && RecoveryInProgress())
ereport(ERROR,
@@ -352,7 +353,7 @@ replorigin_state_clear(RepOriginId roident, bool nowait)
restart:
LWLockAcquire(ReplicationOriginLock, LW_EXCLUSIVE);
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationState *state = &replication_states[i];
@@ -511,18 +512,38 @@ ReplicationOriginShmemSize(void)
{
Size size = 0;
- /*
- * XXX: max_replication_slots is arguably the wrong thing to use, as here
- * we keep the replay state of *remote* transactions. But for now it seems
- * sufficient to reuse it, rather than introduce a separate GUC.
- */
- if (max_replication_slots == 0)
+ if (max_replication_origins == 0)
return size;
+ /*
+ * Prior to PostgreSQL 18, max_replication_slots was used to set the
+ * number of replication origins. For backward compatibility, -1 indicates
+ * to use the fallback value (max_replication_slots).
+ */
+ if (max_replication_origins == -1)
+ {
+ char buf[32];
+
+ snprintf(buf, sizeof(buf), "%d", max_replication_slots);
+ SetConfigOption("max_replication_origins", buf,
+ PGC_POSTMASTER, PGC_S_DYNAMIC_DEFAULT);
+
+ /*
+ * We prefer to report this value's source as PGC_S_DYNAMIC_DEFAULT.
+ * However, if the DBA explicitly set max_replication_origins = -1 in
+ * the config file, then PGC_S_DYNAMIC_DEFAULT will fail to override
+ * that and we must force the matter with PGC_S_OVERRIDE.
+ */
+ if (max_replication_origins == -1) /* failed to apply it? */
+ SetConfigOption("max_replication_origins", buf,
+ PGC_POSTMASTER, PGC_S_OVERRIDE);
+ }
+ Assert(max_replication_origins != -1);
+
size = add_size(size, offsetof(ReplicationStateCtl, states));
size = add_size(size,
- mul_size(max_replication_slots, sizeof(ReplicationState)));
+ mul_size(max_replication_origins, sizeof(ReplicationState)));
return size;
}
@@ -531,7 +552,7 @@ ReplicationOriginShmemInit(void)
{
bool found;
- if (max_replication_slots == 0)
+ if (max_replication_origins == 0)
return;
replication_states_ctl = (ReplicationStateCtl *)
@@ -548,7 +569,7 @@ ReplicationOriginShmemInit(void)
replication_states_ctl->tranche_id = LWTRANCHE_REPLICATION_ORIGIN_STATE;
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
LWLockInitialize(&replication_states[i].lock,
replication_states_ctl->tranche_id);
@@ -570,7 +591,7 @@ ReplicationOriginShmemInit(void)
*
* So its just the magic, followed by the statically sized
* ReplicationStateOnDisk structs. Note that the maximum number of
- * ReplicationState is determined by max_replication_slots.
+ * ReplicationState is determined by max_replication_origins.
* ---------------------------------------------------------------------------
*/
void
@@ -583,7 +604,7 @@ CheckPointReplicationOrigin(void)
uint32 magic = REPLICATION_STATE_MAGIC;
pg_crc32c crc;
- if (max_replication_slots == 0)
+ if (max_replication_origins == 0)
return;
INIT_CRC32C(crc);
@@ -625,7 +646,7 @@ CheckPointReplicationOrigin(void)
LWLockAcquire(ReplicationOriginLock, LW_SHARED);
/* write actual data */
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationStateOnDisk disk_state;
ReplicationState *curstate = &replication_states[i];
@@ -718,7 +739,7 @@ StartupReplicationOrigin(void)
already_started = true;
#endif
- if (max_replication_slots == 0)
+ if (max_replication_origins == 0)
return;
INIT_CRC32C(crc);
@@ -728,8 +749,8 @@ StartupReplicationOrigin(void)
fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
/*
- * might have had max_replication_slots == 0 last run, or we just brought
- * up a standby.
+ * might have had max_replication_origins == 0 last run, or we just
+ * brought up a standby.
*/
if (fd < 0 && errno == ENOENT)
return;
@@ -796,10 +817,10 @@ StartupReplicationOrigin(void)
COMP_CRC32C(crc, &disk_state, sizeof(disk_state));
- if (last_state == max_replication_slots)
+ if (last_state == max_replication_origins)
ereport(PANIC,
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
- errmsg("could not find free replication state, increase \"max_replication_slots\"")));
+ errmsg("could not find free replication state, increase \"max_replication_origins\"")));
/* copy data to shared memory */
replication_states[last_state].roident = disk_state.roident;
@@ -852,7 +873,7 @@ replorigin_redo(XLogReaderState *record)
xlrec = (xl_replorigin_drop *) XLogRecGetData(record);
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationState *state = &replication_states[i];
@@ -917,7 +938,7 @@ replorigin_advance(RepOriginId node,
* Search for either an existing slot for the origin, or a free one we can
* use.
*/
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationState *curstate = &replication_states[i];
@@ -958,7 +979,7 @@ replorigin_advance(RepOriginId node,
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
errmsg("could not find free replication state slot for replication origin with ID %d",
node),
- errhint("Increase \"max_replication_slots\" and try again.")));
+ errhint("Increase \"max_replication_origins\" and try again.")));
if (replication_state == NULL)
{
@@ -1024,7 +1045,7 @@ replorigin_get_progress(RepOriginId node, bool flush)
/* prevent slots from being concurrently dropped */
LWLockAcquire(ReplicationOriginLock, LW_SHARED);
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationState *state;
@@ -1110,7 +1131,7 @@ replorigin_session_setup(RepOriginId node, int acquired_by)
registered_cleanup = true;
}
- Assert(max_replication_slots > 0);
+ Assert(max_replication_origins > 0);
if (session_replication_state != NULL)
ereport(ERROR,
@@ -1124,7 +1145,7 @@ replorigin_session_setup(RepOriginId node, int acquired_by)
* Search for either an existing slot for the origin, or a free one we can
* use.
*/
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationState *curstate = &replication_states[i];
@@ -1159,7 +1180,7 @@ replorigin_session_setup(RepOriginId node, int acquired_by)
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
errmsg("could not find free replication state slot for replication origin with ID %d",
node),
- errhint("Increase \"max_replication_slots\" and try again.")));
+ errhint("Increase \"max_replication_origins\" and try again.")));
else if (session_replication_state == NULL)
{
/* initialize new slot */
@@ -1195,7 +1216,7 @@ replorigin_session_reset(void)
{
ConditionVariable *cv;
- Assert(max_replication_slots != 0);
+ Assert(max_replication_origins != 0);
if (session_replication_state == NULL)
ereport(ERROR,
@@ -1536,7 +1557,7 @@ pg_show_replication_origin_status(PG_FUNCTION_ARGS)
* filled. Note that we do not take any locks, so slightly corrupted/out
* of date values are a possibility.
*/
- for (i = 0; i < max_replication_slots; i++)
+ for (i = 0; i < max_replication_origins; i++)
{
ReplicationState *state;
Datum values[REPLICATION_ORIGIN_PROGRESS_COLS];
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index c9d8cd796a..72f5218b1a 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -3278,6 +3278,18 @@ struct config_int ConfigureNamesInt[] =
NULL, NULL, NULL
},
+ {
+ {"max_replication_origins",
+ PGC_POSTMASTER,
+ REPLICATION_SUBSCRIBERS,
+ gettext_noop("Sets the maximum number of simultaneously defined replication origins."),
+ NULL
+ },
+ &max_replication_origins,
+ -1, -1, MAX_BACKENDS,
+ NULL, NULL, NULL
+ },
+
{
{"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
gettext_noop("Sets the amount of time to wait before forcing "
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index b2bc43383d..785238ae76 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -383,6 +383,9 @@
#max_logical_replication_workers = 4 # taken from max_worker_processes
# (change requires restart)
+#max_replication_origins = -1 # maximum number of replication origins
+ # -1 to use max_replication_slots
+ # (change requires restart)
#max_sync_workers_per_subscription = 2 # taken from max_logical_replication_workers
#max_parallel_apply_workers_per_subscription = 2 # taken from max_logical_replication_workers
diff --git a/src/bin/pg_basebackup/pg_createsubscriber.c b/src/bin/pg_basebackup/pg_createsubscriber.c
index faf18ccf13..4cbeeb5021 100644
--- a/src/bin/pg_basebackup/pg_createsubscriber.c
+++ b/src/bin/pg_basebackup/pg_createsubscriber.c
@@ -964,7 +964,7 @@ check_subscriber(const struct LogicalRepInfo *dbinfo)
bool failed = false;
int max_lrworkers;
- int max_repslots;
+ int max_reporigins;
int max_wprocs;
pg_log_info("checking settings on subscriber");
@@ -983,7 +983,7 @@ check_subscriber(const struct LogicalRepInfo *dbinfo)
* Since these parameters are not a requirement for physical replication,
* we should check it to make sure it won't fail.
*
- * - max_replication_slots >= number of dbs to be converted
+ * - max_replication_origins >= number of dbs to be converted
* - max_logical_replication_workers >= number of dbs to be converted
* - max_worker_processes >= 1 + number of dbs to be converted
*------------------------------------------------------------------------
@@ -991,7 +991,7 @@ check_subscriber(const struct LogicalRepInfo *dbinfo)
res = PQexec(conn,
"SELECT setting FROM pg_catalog.pg_settings WHERE name IN ("
"'max_logical_replication_workers', "
- "'max_replication_slots', "
+ "'max_replication_origins', "
"'max_worker_processes', "
"'primary_slot_name') "
"ORDER BY name");
@@ -1004,14 +1004,14 @@ check_subscriber(const struct LogicalRepInfo *dbinfo)
}
max_lrworkers = atoi(PQgetvalue(res, 0, 0));
- max_repslots = atoi(PQgetvalue(res, 1, 0));
+ max_reporigins = atoi(PQgetvalue(res, 1, 0));
max_wprocs = atoi(PQgetvalue(res, 2, 0));
if (strcmp(PQgetvalue(res, 3, 0), "") != 0)
primary_slot_name = pg_strdup(PQgetvalue(res, 3, 0));
pg_log_debug("subscriber: max_logical_replication_workers: %d",
max_lrworkers);
- pg_log_debug("subscriber: max_replication_slots: %d", max_repslots);
+ pg_log_debug("subscriber: max_replication_origins: %d", max_reporigins);
pg_log_debug("subscriber: max_worker_processes: %d", max_wprocs);
if (primary_slot_name)
pg_log_debug("subscriber: primary_slot_name: %s", primary_slot_name);
@@ -1020,12 +1020,12 @@ check_subscriber(const struct LogicalRepInfo *dbinfo)
disconnect_database(conn, false);
- if (max_repslots < num_dbs)
+ if (max_reporigins < num_dbs)
{
- pg_log_error("subscriber requires %d replication slots, but only %d remain",
- num_dbs, max_repslots);
+ pg_log_error("subscriber requires %d replication origins, but only %d remain",
+ num_dbs, max_reporigins);
pg_log_error_hint("Increase the configuration parameter \"%s\" to at least %d.",
- "max_replication_slots", num_dbs);
+ "max_replication_origins", num_dbs);
failed = true;
}
diff --git a/src/bin/pg_basebackup/t/040_pg_createsubscriber.pl b/src/bin/pg_basebackup/t/040_pg_createsubscriber.pl
index 5426159fa5..40f3f420dd 100644
--- a/src/bin/pg_basebackup/t/040_pg_createsubscriber.pl
+++ b/src/bin/pg_basebackup/t/040_pg_createsubscriber.pl
@@ -262,7 +262,7 @@ max_worker_processes = 8
# Check some unmet conditions on node S
$node_s->append_conf(
'postgresql.conf', q{
-max_replication_slots = 1
+max_replication_origins = 1
max_logical_replication_workers = 1
max_worker_processes = 2
});
@@ -280,7 +280,7 @@ command_fails(
'standby contains unmet conditions on node S');
$node_s->append_conf(
'postgresql.conf', q{
-max_replication_slots = 10
+max_replication_origins = 10
max_logical_replication_workers = 4
max_worker_processes = 8
});
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 7ca1d8fffc..51d9f7408d 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -1815,7 +1815,7 @@ check_new_cluster_logical_replication_slots(void)
/*
* check_new_cluster_subscription_configuration()
*
- * Verify that the max_replication_slots configuration specified is enough for
+ * Verify that the max_replication_origins configuration specified is enough for
* creating the subscriptions. This is required to create the replication
* origin for each subscription.
*/
@@ -1824,7 +1824,7 @@ check_new_cluster_subscription_configuration(void)
{
PGresult *res;
PGconn *conn;
- int max_replication_slots;
+ int max_replication_origins;
/* Subscriptions and their dependencies can be migrated since PG17. */
if (GET_MAJOR_VERSION(old_cluster.major_version) < 1700)
@@ -1839,16 +1839,16 @@ check_new_cluster_subscription_configuration(void)
conn = connectToServer(&new_cluster, "template1");
res = executeQueryOrDie(conn, "SELECT setting FROM pg_settings "
- "WHERE name = 'max_replication_slots';");
+ "WHERE name = 'max_replication_origins';");
if (PQntuples(res) != 1)
pg_fatal("could not determine parameter settings on new cluster");
- max_replication_slots = atoi(PQgetvalue(res, 0, 0));
- if (old_cluster.nsubs > max_replication_slots)
- pg_fatal("\"max_replication_slots\" (%d) must be greater than or equal to the number of "
+ max_replication_origins = atoi(PQgetvalue(res, 0, 0));
+ if (old_cluster.nsubs > max_replication_origins)
+ pg_fatal("\"max_replication_origins\" (%d) must be greater than or equal to the number of "
"subscriptions (%d) on the old cluster",
- max_replication_slots, old_cluster.nsubs);
+ max_replication_origins, old_cluster.nsubs);
PQclear(res);
PQfinish(conn);
diff --git a/src/bin/pg_upgrade/t/004_subscription.pl b/src/bin/pg_upgrade/t/004_subscription.pl
index 661a2715c6..043a538ee4 100644
--- a/src/bin/pg_upgrade/t/004_subscription.pl
+++ b/src/bin/pg_upgrade/t/004_subscription.pl
@@ -41,7 +41,7 @@ chdir ${PostgreSQL::Test::Utils::tmp_check};
my $connstr = $publisher->connstr . ' dbname=postgres';
# ------------------------------------------------------
-# Check that pg_upgrade fails when max_replication_slots configured in the new
+# Check that pg_upgrade fails when max_replication_origins configured in the new
# cluster is less than the number of subscriptions in the old cluster.
# ------------------------------------------------------
# It is sufficient to use disabled subscription to test upgrade failure.
@@ -52,10 +52,10 @@ $old_sub->safe_psql('postgres',
$old_sub->stop;
-$new_sub->append_conf('postgresql.conf', "max_replication_slots = 0");
+$new_sub->append_conf('postgresql.conf', "max_replication_origins = 0");
# pg_upgrade will fail because the new cluster has insufficient
-# max_replication_slots.
+# max_replication_origins.
command_checks_all(
[
'pg_upgrade', '--no-sync', '-d', $old_sub->data_dir,
@@ -66,14 +66,14 @@ command_checks_all(
],
1,
[
- qr/"max_replication_slots" \(0\) must be greater than or equal to the number of subscriptions \(1\) on the old cluster/
+ qr/"max_replication_origins" \(0\) must be greater than or equal to the number of subscriptions \(1\) on the old cluster/
],
[qr//],
- 'run of pg_upgrade where the new cluster has insufficient max_replication_slots'
+ 'run of pg_upgrade where the new cluster has insufficient max_replication_origins'
);
-# Reset max_replication_slots
-$new_sub->append_conf('postgresql.conf', "max_replication_slots = 10");
+# Reset max_replication_origins
+$new_sub->append_conf('postgresql.conf', "max_replication_origins = 10");
# Cleanup
$publisher->safe_psql('postgres', "DROP PUBLICATION regress_pub1");
diff --git a/src/include/replication/origin.h b/src/include/replication/origin.h
index 33a7e59ddb..8f65d4ef30 100644
--- a/src/include/replication/origin.h
+++ b/src/include/replication/origin.h
@@ -37,6 +37,9 @@ extern PGDLLIMPORT RepOriginId replorigin_session_origin;
extern PGDLLIMPORT XLogRecPtr replorigin_session_origin_lsn;
extern PGDLLIMPORT TimestampTz replorigin_session_origin_timestamp;
+/* GUCs */
+extern PGDLLIMPORT int max_replication_origins;
+
/* API for querying & manipulating replication origins */
extern RepOriginId replorigin_by_name(const char *roname, bool missing_ok);
extern RepOriginId replorigin_create(const char *roname);
--
2.39.5
