mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-12-09 08:10:09 +08:00
3fa17d3771
Previously, we used to use the array of size max_replication_slots to store stats for replication slots. But that had two problems in the cases where a message for dropping a slot gets lost: 1) the stats for the new slot are not recorded if the array is full and 2) writing beyond the end of the array if the user reduces the max_replication_slots. This commit uses HTAB for replication slot statistics, resolving both problems. Now, pgstat_vacuum_stat() search for all the dead replication slots in stats hashtable and tell the collector to remove them. To avoid showing the stats for the already-dropped slots, pg_stat_replication_slots view searches slot stats by the slot name taken from pg_replication_slots. Also, we send a message for creating a slot at slot creation, initializing the stats. This reduces the possibility that the stats are accumulated into the old slot stats when a message for dropping a slot gets lost. Reported-by: Andres Freund Author: Sawada Masahiko, test case by Vignesh C Reviewed-by: Amit Kapila, Vignesh C, Dilip Kumar Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
116 lines
3.7 KiB
Perl
116 lines
3.7 KiB
Perl
# Test replication statistics data in pg_stat_replication_slots is sane after
|
|
# drop replication slot and restart.
|
|
use strict;
|
|
use warnings;
|
|
use File::Path qw(rmtree);
|
|
use PostgresNode;
|
|
use TestLib;
|
|
use Test::More tests => 2;
|
|
|
|
# Test set-up
|
|
my $node = get_new_node('test');
|
|
$node->init(allows_streaming => 'logical');
|
|
$node->append_conf('postgresql.conf', 'synchronous_commit = on');
|
|
$node->start;
|
|
|
|
# Check that replication slot stats are expected.
|
|
sub test_slot_stats
|
|
{
|
|
my ($node, $expected, $msg) = @_;
|
|
|
|
my $result = $node->safe_psql(
|
|
'postgres', qq[
|
|
SELECT slot_name, total_txns > 0 AS total_txn,
|
|
total_bytes > 0 AS total_bytes
|
|
FROM pg_stat_replication_slots
|
|
ORDER BY slot_name]);
|
|
is($result, $expected, $msg);
|
|
}
|
|
|
|
# Create table.
|
|
$node->safe_psql('postgres', "CREATE TABLE test_repl_stat(col1 int)");
|
|
|
|
# Create replication slots.
|
|
$node->safe_psql(
|
|
'postgres', qq[
|
|
SELECT pg_create_logical_replication_slot('regression_slot1', 'test_decoding');
|
|
SELECT pg_create_logical_replication_slot('regression_slot2', 'test_decoding');
|
|
SELECT pg_create_logical_replication_slot('regression_slot3', 'test_decoding');
|
|
SELECT pg_create_logical_replication_slot('regression_slot4', 'test_decoding');
|
|
]);
|
|
|
|
# Insert some data.
|
|
$node->safe_psql('postgres',
|
|
"INSERT INTO test_repl_stat values(generate_series(1, 5));");
|
|
|
|
$node->safe_psql(
|
|
'postgres', qq[
|
|
SELECT data FROM pg_logical_slot_get_changes('regression_slot1', NULL,
|
|
NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
|
|
SELECT data FROM pg_logical_slot_get_changes('regression_slot2', NULL,
|
|
NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
|
|
SELECT data FROM pg_logical_slot_get_changes('regression_slot3', NULL,
|
|
NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
|
|
SELECT data FROM pg_logical_slot_get_changes('regression_slot4', NULL,
|
|
NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
|
|
]);
|
|
|
|
# Wait for the statistics to be updated.
|
|
$node->poll_query_until(
|
|
'postgres', qq[
|
|
SELECT count(slot_name) >= 4 FROM pg_stat_replication_slots
|
|
WHERE slot_name ~ 'regression_slot'
|
|
AND total_txns > 0 AND total_bytes > 0;
|
|
]) or die "Timed out while waiting for statistics to be updated";
|
|
|
|
# Test to drop one of the replication slot and verify replication statistics data is
|
|
# fine after restart.
|
|
$node->safe_psql('postgres',
|
|
"SELECT pg_drop_replication_slot('regression_slot4')");
|
|
|
|
$node->stop;
|
|
$node->start;
|
|
|
|
# Verify statistics data present in pg_stat_replication_slots are sane after
|
|
# restart.
|
|
test_slot_stats(
|
|
$node,
|
|
qq(regression_slot1|t|t
|
|
regression_slot2|t|t
|
|
regression_slot3|t|t),
|
|
'check replication statistics are updated');
|
|
|
|
# Test to remove one of the replication slots and adjust
|
|
# max_replication_slots accordingly to the number of slots. This leads
|
|
# to a mismatch between the number of slots present in the stats file and the
|
|
# number of stats present in the shared memory, simulating the scenario for
|
|
# drop slot message lost by the statistics collector process. We verify
|
|
# replication statistics data is fine after restart.
|
|
|
|
$node->stop;
|
|
my $datadir = $node->data_dir;
|
|
my $slot3_replslotdir = "$datadir/pg_replslot/regression_slot3";
|
|
|
|
rmtree($slot3_replslotdir);
|
|
|
|
$node->append_conf('postgresql.conf', 'max_replication_slots = 2');
|
|
$node->start;
|
|
|
|
# Verify statistics data present in pg_stat_replication_slots are sane after
|
|
# restart.
|
|
test_slot_stats(
|
|
$node,
|
|
qq(regression_slot1|t|t
|
|
regression_slot2|t|t),
|
|
'check replication statistics after removing the slot file');
|
|
|
|
# cleanup
|
|
$node->safe_psql('postgres', "DROP TABLE test_repl_stat");
|
|
$node->safe_psql('postgres',
|
|
"SELECT pg_drop_replication_slot('regression_slot1')");
|
|
$node->safe_psql('postgres',
|
|
"SELECT pg_drop_replication_slot('regression_slot2')");
|
|
|
|
# shutdown
|
|
$node->stop;
|