From a56f565689b8b18573acd873a097a213af6c6722 Mon Sep 17 00:00:00 2001 From: Vignesh C Date: Wed, 25 Sep 2024 14:42:20 +0530 Subject: [PATCH v3] Make default value for susbcription streaming option to parallel. Currently default value of streaming option is set to false. All transactions are fully decoded on the publisher before being sent to the subscriber. This approach can leads reduced performance, particularly under heavy load. Changing default streaming option to parallel, by doing this, incoming changes will be directly applied by one of the available parallel apply workers. This method significantly improves the performance of commit operations. --- doc/src/sgml/ref/create_subscription.sgml | 27 ++++++++++++++-------- src/backend/commands/subscriptioncmds.c | 2 +- src/bin/pg_dump/pg_dump.c | 2 ++ src/bin/pg_dump/t/002_pg_dump.pl | 10 ++++---- src/test/regress/expected/subscription.out | 24 +++++++++---------- 5 files changed, 37 insertions(+), 28 deletions(-) diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml index 8a3096e62b..3eab06bd2d 100644 --- a/doc/src/sgml/ref/create_subscription.sgml +++ b/doc/src/sgml/ref/create_subscription.sgml @@ -271,11 +271,23 @@ CREATE SUBSCRIPTION subscription_name Specifies whether to enable streaming of in-progress transactions - for this subscription. The default value is off, - meaning all transactions are fully decoded on the publisher and only - then sent to the subscriber as a whole. + for this subscription. The default value is parallel, + meaning incoming changes are directly applied via one of the parallel + apply workers, if available. If no parallel apply worker is free to + handle streaming transactions then the changes are written to + temporary files and applied after the transaction is committed. Note + that if an error happens in a parallel apply worker, the finish LSN + of the remote transaction might not be reported in the server log. + + + There is a risk of deadlock when the schemas of the publisher and + subscriber differ, although such cases are rare. The apply worker + is equipped to automatically retry these transactions. + + + If set to on, the incoming changes are written to temporary files and then applied only after the transaction is @@ -283,13 +295,8 @@ CREATE SUBSCRIPTION subscription_name - If set to parallel, incoming changes are directly - applied via one of the parallel apply workers, if available. If no - parallel apply worker is free to handle streaming transactions then - the changes are written to temporary files and applied after the - transaction is committed. Note that if an error happens in a - parallel apply worker, the finish LSN of the remote transaction - might not be reported in the server log. + If set to off, all transactions are fully decoded + on the publisher and only then sent to the subscriber as a whole. diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c index 02ccc636b8..0a7a618855 100644 --- a/src/backend/commands/subscriptioncmds.c +++ b/src/backend/commands/subscriptioncmds.c @@ -151,7 +151,7 @@ parse_subscription_options(ParseState *pstate, List *stmt_options, if (IsSet(supported_opts, SUBOPT_BINARY)) opts->binary = false; if (IsSet(supported_opts, SUBOPT_STREAMING)) - opts->streaming = LOGICALREP_STREAM_OFF; + opts->streaming = LOGICALREP_STREAM_PARALLEL; if (IsSet(supported_opts, SUBOPT_TWOPHASE_COMMIT)) opts->twophase = false; if (IsSet(supported_opts, SUBOPT_DISABLE_ON_ERR)) diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index 1d79865058..19e3d24326 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -5248,6 +5248,8 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo) appendPQExpBufferStr(query, ", streaming = on"); else if (strcmp(subinfo->substream, "p") == 0) appendPQExpBufferStr(query, ", streaming = parallel"); + else + appendPQExpBufferStr(query, ", streaming = off"); if (strcmp(subinfo->subtwophasestate, two_phase_disabled) != 0) appendPQExpBufferStr(query, ", two_phase = on"); diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl index 91a4c63744..213904440f 100644 --- a/src/bin/pg_dump/t/002_pg_dump.pl +++ b/src/bin/pg_dump/t/002_pg_dump.pl @@ -3002,7 +3002,7 @@ my %tests = ( CONNECTION \'dbname=doesnotexist\' PUBLICATION pub1 WITH (connect = false);', regexp => qr/^ - \QCREATE SUBSCRIPTION sub1 CONNECTION 'dbname=doesnotexist' PUBLICATION pub1 WITH (connect = false, slot_name = 'sub1');\E + \QCREATE SUBSCRIPTION sub1 CONNECTION 'dbname=doesnotexist' PUBLICATION pub1 WITH (connect = false, slot_name = 'sub1', streaming = parallel);\E /xm, like => { %full_runs, section_post_data => 1, }, }, @@ -3011,9 +3011,9 @@ my %tests = ( create_order => 50, create_sql => 'CREATE SUBSCRIPTION sub2 CONNECTION \'dbname=doesnotexist\' PUBLICATION pub1 - WITH (connect = false, origin = none);', + WITH (connect = false, origin = none, streaming = off);', regexp => qr/^ - \QCREATE SUBSCRIPTION sub2 CONNECTION 'dbname=doesnotexist' PUBLICATION pub1 WITH (connect = false, slot_name = 'sub2', origin = none);\E + \QCREATE SUBSCRIPTION sub2 CONNECTION 'dbname=doesnotexist' PUBLICATION pub1 WITH (connect = false, slot_name = 'sub2', streaming = off, origin = none);\E /xm, like => { %full_runs, section_post_data => 1, }, }, @@ -3022,9 +3022,9 @@ my %tests = ( create_order => 50, create_sql => 'CREATE SUBSCRIPTION sub3 CONNECTION \'dbname=doesnotexist\' PUBLICATION pub1 - WITH (connect = false, origin = any);', + WITH (connect = false, origin = any, streaming = on);', regexp => qr/^ - \QCREATE SUBSCRIPTION sub3 CONNECTION 'dbname=doesnotexist' PUBLICATION pub1 WITH (connect = false, slot_name = 'sub3');\E + \QCREATE SUBSCRIPTION sub3 CONNECTION 'dbname=doesnotexist' PUBLICATION pub1 WITH (connect = false, slot_name = 'sub3', streaming = on);\E /xm, like => { %full_runs, section_post_data => 1, }, }, diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out index 17d48b1685..1443e1d929 100644 --- a/src/test/regress/expected/subscription.out +++ b/src/test/regress/expected/subscription.out @@ -119,7 +119,7 @@ HINT: To initiate replication, you must manually create the replication slot, e 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 + regress_testsub4 | regress_subscription_user | f | {testpub} | f | parallel | d | f | none | t | f | f | off | dbname=regress_doesnotexist | 0/0 (1 row) ALTER SUBSCRIPTION regress_testsub4 SET (origin = any); @@ -127,7 +127,7 @@ ALTER SUBSCRIPTION regress_testsub4 SET (origin = any); 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 + regress_testsub4 | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0 (1 row) DROP SUBSCRIPTION regress_testsub3; @@ -148,7 +148,7 @@ ERROR: invalid connection string syntax: missing "=" after "foobar" in connecti 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 + 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 PUBLICATION testpub2, testpub3 WITH (refresh = false); @@ -160,7 +160,7 @@ ALTER SUBSCRIPTION regress_testsub SET (run_as_owner = true); 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 + regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | parallel | d | f | any | f | t | f | off | dbname=regress_doesnotexist2 | 0/0 (1 row) ALTER SUBSCRIPTION regress_testsub SET (password_required = true); @@ -179,7 +179,7 @@ ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '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 + regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/12345 (1 row) -- ok - with lsn = NONE @@ -191,7 +191,7 @@ ERROR: invalid WAL location (LSN): 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 + regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/0 (1 row) BEGIN; @@ -226,7 +226,7 @@ HINT: Available values: local, remote_write, remote_apply, on, off. 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 + regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | parallel | d | f | any | t | f | f | local | dbname=regress_doesnotexist2 | 0/0 (1 row) -- rename back to keep the rest simple @@ -258,7 +258,7 @@ HINT: To initiate replication, you must manually create the replication slot, e 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 + regress_testsub | regress_subscription_user | f | {testpub} | t | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0 (1 row) ALTER SUBSCRIPTION regress_testsub SET (binary = false); @@ -267,7 +267,7 @@ ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE); 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 + regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0 (1 row) DROP SUBSCRIPTION regress_testsub; @@ -374,7 +374,7 @@ HINT: To initiate replication, you must manually create the replication slot, e 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 + regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0 (1 row) -- we can alter streaming when two_phase enabled @@ -412,7 +412,7 @@ HINT: To initiate replication, you must manually create the replication slot, e 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 + 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 (disable_on_error = true); @@ -420,7 +420,7 @@ ALTER SUBSCRIPTION regress_testsub SET (disable_on_error = true); 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 + regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | t | any | t | f | f | off | dbname=regress_doesnotexist | 0/0 (1 row) ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE); -- 2.34.1