From b29cbd3da4e37db17026b9fe58fb46fe83f467bf Mon Sep 17 00:00:00 2001 From: Amit Kapila Date: Tue, 23 Apr 2024 12:14:57 +0530 Subject: [PATCH] Fix the handling of the failover option in subscription commands. Do not allow ALTER SUBSCRIPTION ... SET (failover = on|off) in a transaction block as the changed failover option of the slot can't be rolled back. For the same reason, we refrain from altering the replication slot's failover property if the subscription is created with a valid slot_name and create_slot=false. Reprted-by: Kuroda Hayato Author: Hou Zhijie Reviewed-by: Shveta Malik, Bertrand Drouvot, Kuroda Hayato Discussion: https://postgr.es/m/OS0PR01MB57165542B09DFA4943830BF294082@OS0PR01MB5716.jpnprd01.prod.outlook.com --- doc/src/sgml/ref/alter_subscription.sgml | 7 +++-- doc/src/sgml/ref/create_subscription.sgml | 18 ++++++++++-- doc/src/sgml/ref/pg_dump.sgml | 6 +--- src/backend/commands/subscriptioncmds.c | 28 ++++--------------- src/bin/pg_dump/pg_dump.c | 27 ++++++++---------- .../t/040_standby_failover_slots_sync.pl | 20 ++----------- src/test/regress/expected/subscription.out | 7 +++-- src/test/regress/sql/subscription.sql | 6 +++- 8 files changed, 52 insertions(+), 67 deletions(-) diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml index 413ce68ce2..a78c1c3a47 100644 --- a/doc/src/sgml/ref/alter_subscription.sgml +++ b/doc/src/sgml/ref/alter_subscription.sgml @@ -66,10 +66,11 @@ ALTER SUBSCRIPTION name RENAME TO < - Commands ALTER SUBSCRIPTION ... REFRESH PUBLICATION and + Commands ALTER SUBSCRIPTION ... REFRESH PUBLICATION, ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ... - with refresh option as true cannot be - executed inside a transaction block. + with refresh option as true and + ALTER SUBSCRIPTION ... SET (failover = on|off) + cannot be executed inside a transaction block. These commands also cannot be executed when the subscription has two_phase diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml index 15794731bb..740b7d9421 100644 --- a/doc/src/sgml/ref/create_subscription.sgml +++ b/doc/src/sgml/ref/create_subscription.sgml @@ -122,8 +122,7 @@ CREATE SUBSCRIPTION subscription_nameconnect to false with setting create_slot, enabled, - copy_data, or failover to - true.) + or copy_data to true.) @@ -183,6 +182,21 @@ CREATE SUBSCRIPTION subscription_name for examples. + + + When setting slot_name to a valid name and + create_slot to false, the + failover property value of the named slot may + differ from the counterpart failover parameter + specified in the subscription. Always ensure the slot property + failover matches the counterpart parameter of the + subscription and vice versa. Otherwise, the slot on the publisher may + behave differently from what these subscription options say: for + example, the slot on the publisher could either be synced to the + standbys even when the subscription's failover + option is disabled or could be disabled for sync even when the + subscription's failover option is enabled. + diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml index b99793e414..671df4b60e 100644 --- a/doc/src/sgml/ref/pg_dump.sgml +++ b/doc/src/sgml/ref/pg_dump.sgml @@ -1611,11 +1611,7 @@ CREATE DATABASE foo WITH TEMPLATE template0; dump can be restored without requiring network access to the remote servers. It is then up to the user to reactivate the subscriptions in a suitable way. If the involved hosts have changed, the connection - information might have to be changed. If the subscription needs to - be enabled for - failover, - execute ALTER SUBSCRIPTION ... SET (failover = true) - after the slot has been created. It might also be appropriate to + information might have to be changed. It might also be appropriate to truncate the target tables before initiating a new full table copy. If users intend to copy initial data during refresh they must create the slot with two_phase = false. After the initial sync, the diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c index 5a47fa984d..e407428dbc 100644 --- a/src/backend/commands/subscriptioncmds.c +++ b/src/backend/commands/subscriptioncmds.c @@ -401,13 +401,6 @@ parse_subscription_options(ParseState *pstate, List *stmt_options, errmsg("%s and %s are mutually exclusive options", "connect = false", "copy_data = true"))); - if (opts->failover && - IsSet(opts->specified_opts, SUBOPT_FAILOVER)) - ereport(ERROR, - (errcode(ERRCODE_SYNTAX_ERROR), - errmsg("%s and %s are mutually exclusive options", - "connect = false", "failover = true"))); - /* Change the defaults of other options. */ opts->enabled = false; opts->create_slot = false; @@ -836,21 +829,6 @@ 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); - } } PG_FINALLY(); { @@ -1267,6 +1245,12 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt, errmsg("cannot set %s for enabled subscription", "failover"))); + /* + * The changed failover option of the slot can't be rolled + * back. + */ + PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (failover)"); + values[Anum_pg_subscription_subfailover - 1] = BoolGetDatum(opts.failover); replaces[Anum_pg_subscription_subfailover - 1] = true; diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index ed9bab3bfe..b8acdd7355 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -4804,12 +4804,17 @@ getSubscriptions(Archive *fout) if (dopt->binary_upgrade && fout->remoteVersion >= 170000) appendPQExpBufferStr(query, " o.remote_lsn AS suboriginremotelsn,\n" - " s.subenabled,\n" - " s.subfailover\n"); + " s.subenabled,\n"); else appendPQExpBufferStr(query, " NULL AS suboriginremotelsn,\n" - " false AS subenabled,\n" - " false AS subfailover\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"); @@ -5132,6 +5137,9 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo) if (strcmp(subinfo->subrunasowner, "t") == 0) appendPQExpBufferStr(query, ", run_as_owner = true"); + if (strcmp(subinfo->subfailover, "t") == 0) + appendPQExpBufferStr(query, ", failover = true"); + if (strcmp(subinfo->subsynccommit, "off") != 0) appendPQExpBuffer(query, ", synchronous_commit = %s", fmtId(subinfo->subsynccommit)); @@ -5165,17 +5173,6 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo) appendPQExpBuffer(query, ", '%s');\n", subinfo->suboriginremotelsn); } - if (strcmp(subinfo->subfailover, "t") == 0) - { - /* - * Enable the failover to allow the subscription's slot to be - * synced to the standbys after the upgrade. - */ - appendPQExpBufferStr(query, - "\n-- For binary upgrade, must preserve the subscriber's failover option.\n"); - appendPQExpBuffer(query, "ALTER SUBSCRIPTION %s SET(failover = true);\n", qsubname); - } - if (strcmp(subinfo->subenabled, "t") == 0) { /* diff --git a/src/test/recovery/t/040_standby_failover_slots_sync.pl b/src/test/recovery/t/040_standby_failover_slots_sync.pl index 76545e3c74..12acf874d7 100644 --- a/src/test/recovery/t/040_standby_failover_slots_sync.pl +++ b/src/test/recovery/t/040_standby_failover_slots_sync.pl @@ -42,26 +42,12 @@ my $slot_creation_time_on_primary = $publisher->safe_psql( SELECT current_timestamp; ]); -# Create a slot on the publisher with failover disabled -$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. +# Create a subscription 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);" + "CREATE SUBSCRIPTION regress_mysub1 CONNECTION '$publisher_connstr' PUBLICATION regress_mypub WITH (slot_name = lsub1_slot, copy_data = false, failover = true, enabled = false);" ); -# Confirm that the failover flag on the slot has now been turned on +# Confirm that the failover flag on the slot is turned on is( $publisher->safe_psql( 'postgres', q{SELECT failover from pg_replication_slots WHERE slot_name = 'lsub1_slot';} diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out index 1eee6b17b8..0f2a25cdc1 100644 --- a/src/test/regress/expected/subscription.out +++ b/src/test/regress/expected/subscription.out @@ -89,8 +89,6 @@ CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PU ERROR: connect = false and enabled = true are mutually exclusive options CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, create_slot = true); ERROR: connect = false and create_slot = true are mutually exclusive options -CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, failover = true); -ERROR: connect = false and failover = true are mutually exclusive options CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (slot_name = NONE, enabled = true); ERROR: slot_name = NONE and enabled = true are mutually exclusive options CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (slot_name = NONE, enabled = false, create_slot = true); @@ -472,6 +470,11 @@ REVOKE CREATE ON DATABASE REGRESSION FROM regress_subscription_user3; SET SESSION AUTHORIZATION regress_subscription_user3; ALTER SUBSCRIPTION regress_testsub RENAME TO regress_testsub2; ERROR: permission denied for database regression +-- fail - cannot do ALTER SUBSCRIPTION SET (failover) inside transaction block +BEGIN; +ALTER SUBSCRIPTION regress_testsub SET (failover); +ERROR: ALTER SUBSCRIPTION ... SET (failover) cannot run inside a transaction block +COMMIT; -- ok, owning it is enough for this stuff ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE); DROP SUBSCRIPTION regress_testsub; diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql index 1b2a23ba7b..3e5ba4cb8c 100644 --- a/src/test/regress/sql/subscription.sql +++ b/src/test/regress/sql/subscription.sql @@ -54,7 +54,6 @@ SET SESSION AUTHORIZATION 'regress_subscription_user'; CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, copy_data = true); CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, enabled = true); CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, create_slot = true); -CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, failover = true); CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (slot_name = NONE, enabled = true); CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (slot_name = NONE, enabled = false, create_slot = true); CREATE SUBSCRIPTION regress_testsub2 CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (slot_name = NONE); @@ -333,6 +332,11 @@ REVOKE CREATE ON DATABASE REGRESSION FROM regress_subscription_user3; SET SESSION AUTHORIZATION regress_subscription_user3; ALTER SUBSCRIPTION regress_testsub RENAME TO regress_testsub2; +-- fail - cannot do ALTER SUBSCRIPTION SET (failover) inside transaction block +BEGIN; +ALTER SUBSCRIPTION regress_testsub SET (failover); +COMMIT; + -- ok, owning it is enough for this stuff ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE); DROP SUBSCRIPTION regress_testsub;