From 196b72fb9a5556c66f2b012cc4e869175a3049fa Mon Sep 17 00:00:00 2001
From: Fujii Masao <fujii@postgresql.org>
Date: Fri, 8 Apr 2016 16:48:53 +0900
Subject: [PATCH] Add regression tests for multiple synchronous standbys.
Authors: Suraj Kharage, Michael Paquier, Masahiko Sawada, refactored by me
Reviewed-By: Kyotaro Horiguchi
---
src/test/perl/PostgresNode.pm | 18 ++++
src/test/recovery/t/007_sync_rep.pl | 149 ++++++++++++++++++++++++++++
2 files changed, 167 insertions(+)
create mode 100644 src/test/recovery/t/007_sync_rep.pl
diff --git a/src/test/perl/PostgresNode.pm b/src/test/perl/PostgresNode.pm
index 2cbd2887ba0..e42c1174cb5 100644
--- a/src/test/perl/PostgresNode.pm
+++ b/src/test/perl/PostgresNode.pm
@@ -668,6 +668,24 @@ sub stop
=pod
+=item $node->reload()
+
+Reload configuration parameters on the node.
+
+=cut
+
+sub reload
+{
+ my ($self) = @_;
+ my $port = $self->port;
+ my $pgdata = $self->data_dir;
+ my $name = $self->name;
+ print "### Reloading node \"$name\"\n";
+ TestLib::system_log('pg_ctl', '-D', $pgdata, 'reload');
+}
+
+=pod
+
=item $node->restart()
Wrapper for pg_ctl -w restart
diff --git a/src/test/recovery/t/007_sync_rep.pl b/src/test/recovery/t/007_sync_rep.pl
new file mode 100644
index 00000000000..c257b6ea166
--- /dev/null
+++ b/src/test/recovery/t/007_sync_rep.pl
@@ -0,0 +1,149 @@
+# Minimal test testing synchronous replication sync_state transition
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use Test::More tests => 8;
+
+# Query checking sync_priority and sync_state of each standby
+my $check_sql = "SELECT application_name, sync_priority, sync_state FROM pg_stat_replication ORDER BY application_name;";
+
+# Check that sync_state of each standby is expected.
+# If $setting is given, synchronous_standby_names is set to it and
+# the configuration file is reloaded before the test.
+sub test_sync_state
+{
+ my ($self, $expected, $msg, $setting) = @_;
+
+ if (defined($setting))
+ {
+ $self->psql('postgres',
+ "ALTER SYSTEM SET synchronous_standby_names = '$setting';");
+ $self->reload;
+ }
+
+ my $result = $self->safe_psql('postgres', $check_sql);
+ is($result, $expected, $msg);
+}
+
+# Initialize master node
+my $node_master = get_new_node('master');
+$node_master->init(allows_streaming => 1);
+$node_master->start;
+my $backup_name = 'master_backup';
+
+# Take backup
+$node_master->backup($backup_name);
+
+# Create standby1 linking to master
+my $node_standby_1 = get_new_node('standby1');
+$node_standby_1->init_from_backup($node_master, $backup_name,
+ has_streaming => 1);
+$node_standby_1->start;
+
+# Create standby2 linking to master
+my $node_standby_2 = get_new_node('standby2');
+$node_standby_2->init_from_backup($node_master, $backup_name,
+ has_streaming => 1);
+$node_standby_2->start;
+
+# Create standby3 linking to master
+my $node_standby_3 = get_new_node('standby3');
+$node_standby_3->init_from_backup($node_master, $backup_name,
+ has_streaming => 1);
+$node_standby_3->start;
+
+# Check that sync_state is determined correctly when
+# synchronous_standby_names is specified in old syntax.
+test_sync_state($node_master, qq(standby1|1|sync
+standby2|2|potential
+standby3|0|async),
+ 'old syntax of synchronous_standby_names',
+ 'standby1,standby2');
+
+# Check that all the standbys are considered as either sync or
+# potential when * is specified in synchronous_standby_names.
+# Note that standby1 is chosen as sync standby because
+# it's stored in the head of WalSnd array which manages
+# all the standbys though they have the same priority.
+test_sync_state($node_master, qq(standby1|1|sync
+standby2|1|potential
+standby3|1|potential),
+ 'asterisk in synchronous_standby_names',
+ '*');
+
+# Stop and start standbys to rearrange the order of standbys
+# in WalSnd array. Now, if standbys have the same priority,
+# standby2 is selected preferentially and standby3 is next.
+$node_standby_1->stop;
+$node_standby_2->stop;
+$node_standby_3->stop;
+
+$node_standby_2->start;
+$node_standby_3->start;
+
+# Specify 2 as the number of sync standbys.
+# Check that two standbys are in 'sync' state.
+test_sync_state($node_master, qq(standby2|2|sync
+standby3|3|sync),
+ '2 synchronous standbys',
+ '2(standby1,standby2,standby3)');
+
+# Start standby1
+$node_standby_1->start;
+
+# Create standby4 linking to master
+my $node_standby_4 = get_new_node('standby4');
+$node_standby_4->init_from_backup($node_master, $backup_name,
+ has_streaming => 1);
+$node_standby_4->start;
+
+# Check that standby1 and standby2 whose names appear earlier in
+# synchronous_standby_names are considered as sync. Also check that
+# standby3 appearing later represents potential, and standby4 is
+# in 'async' state because it's not in the list.
+test_sync_state($node_master, qq(standby1|1|sync
+standby2|2|sync
+standby3|3|potential
+standby4|0|async),
+ '2 sync, 1 potential and 1 async');
+
+# Check that sync_state of each standby is determined correctly
+# when num_sync exceeds the number of names of potential sync standbys
+# specified in synchronous_standby_names.
+test_sync_state($node_master, qq(standby1|0|async
+standby2|4|sync
+standby3|3|sync
+standby4|1|sync),
+ 'num_sync exceeds the num of potential sync standbys',
+ '6(standby4,standby0,standby3,standby2)');
+
+# The setting that * comes before another standby name is acceptable
+# but does not make sense in most cases. Check that sync_state is
+# chosen properly even in case of that setting.
+# The priority of standby2 should be 2 because it matches * first.
+test_sync_state($node_master, qq(standby1|1|sync
+standby2|2|sync
+standby3|2|potential
+standby4|2|potential),
+ 'asterisk comes before another standby name',
+ '2(standby1,*,standby2)');
+
+# Check that the setting of '2(*)' chooses standby2 and standby3 that are stored
+# earlier in WalSnd array as sync standbys.
+test_sync_state($node_master, qq(standby1|1|potential
+standby2|1|sync
+standby3|1|sync
+standby4|1|potential),
+ 'multiple standbys having the same priority are chosen as sync',
+ '2(*)');
+
+# Stop Standby3 which is considered in 'sync' state.
+$node_standby_3->stop;
+
+# Check that the state of standby1 stored earlier in WalSnd array than
+# standby4 is transited from potential to sync.
+test_sync_state($node_master, qq(standby1|1|sync
+standby2|1|sync
+standby4|1|potential),
+ 'potential standby found earlier in array is promoted to sync');
--
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