postgresql/contrib/amcheck/t/003_cic_2pc.pl
Noah Misch a5b9a0000e Fix CREATE INDEX CONCURRENTLY for the newest prepared transactions.
The purpose of commit 8a54e12a38 was to
fix this, and it sufficed when the PREPARE TRANSACTION completed before
the CIC looked for lock conflicts.  Otherwise, things still broke.  As
before, in a cluster having used CIC while having enabled prepared
transactions, queries that use the resulting index can silently fail to
find rows.  It may be necessary to reindex to recover from past
occurrences; REINDEX CONCURRENTLY suffices.  Fix this for future index
builds by making CIC wait for arbitrarily-recent prepared transactions
and for ordinary transactions that may yet PREPARE TRANSACTION.  As part
of that, have PREPARE TRANSACTION transfer locks to its dummy PGPROC
before it calls ProcArrayClearTransaction().  Back-patch to 9.6 (all
supported versions).

Andrey Borodin, reviewed (in earlier versions) by Andres Freund.

Discussion: https://postgr.es/m/01824242-AA92-4FE9-9BA7-AEBAFFEA3D0C@yandex-team.ru
2021-10-23 18:36:42 -07:00

189 lines
4.3 KiB
Perl

# Copyright (c) 2021, PostgreSQL Global Development Group
# Test CREATE INDEX CONCURRENTLY with concurrent prepared-xact modifications
use strict;
use warnings;
use Config;
use PostgresNode;
use TestLib;
use Test::More tests => 6;
my ($node, $result);
#
# Test set-up
#
$node = get_new_node('CIC_2PC_test');
$node->init;
$node->append_conf('postgresql.conf', 'max_prepared_transactions = 10');
$node->append_conf('postgresql.conf', 'lock_timeout = 180000');
$node->start;
$node->safe_psql('postgres', q(CREATE EXTENSION amcheck));
$node->safe_psql('postgres', q(CREATE TABLE tbl(i int)));
#
# Run 3 overlapping 2PC transactions with CIC
#
# We have two concurrent background psql processes: $main_h for INSERTs and
# $cic_h for CIC. Also, we use non-background psql for some COMMIT PREPARED
# statements.
#
my $main_in = '';
my $main_out = '';
my $main_timer = IPC::Run::timeout(180);
my $main_h =
$node->background_psql('postgres', \$main_in, \$main_out,
$main_timer, on_error_stop => 1);
$main_in .= q(
BEGIN;
INSERT INTO tbl VALUES(0);
\echo syncpoint1
);
pump $main_h until $main_out =~ /syncpoint1/ || $main_timer->is_expired;
my $cic_in = '';
my $cic_out = '';
my $cic_timer = IPC::Run::timeout(180);
my $cic_h =
$node->background_psql('postgres', \$cic_in, \$cic_out,
$cic_timer, on_error_stop => 1);
$cic_in .= q(
\echo start
CREATE INDEX CONCURRENTLY idx ON tbl(i);
);
pump $cic_h until $cic_out =~ /start/ || $cic_timer->is_expired;
$main_in .= q(
PREPARE TRANSACTION 'a';
);
$main_in .= q(
BEGIN;
INSERT INTO tbl VALUES(0);
\echo syncpoint2
);
pump $main_h until $main_out =~ /syncpoint2/ || $main_timer->is_expired;
$node->safe_psql('postgres', q(COMMIT PREPARED 'a';));
$main_in .= q(
PREPARE TRANSACTION 'b';
BEGIN;
INSERT INTO tbl VALUES(0);
\echo syncpoint3
);
pump $main_h until $main_out =~ /syncpoint3/ || $main_timer->is_expired;
$node->safe_psql('postgres', q(COMMIT PREPARED 'b';));
$main_in .= q(
PREPARE TRANSACTION 'c';
COMMIT PREPARED 'c';
);
$main_h->pump_nb;
$main_h->finish;
$cic_h->finish;
$result = $node->psql('postgres', q(SELECT bt_index_check('idx',true)));
is($result, '0', 'bt_index_check after overlapping 2PC');
#
# Server restart shall not change whether prepared xact blocks CIC
#
$node->safe_psql(
'postgres', q(
BEGIN;
INSERT INTO tbl VALUES(0);
PREPARE TRANSACTION 'spans_restart';
BEGIN;
CREATE TABLE unused ();
PREPARE TRANSACTION 'persists_forever';
));
$node->restart;
my $reindex_in = '';
my $reindex_out = '';
my $reindex_timer = IPC::Run::timeout(180);
my $reindex_h =
$node->background_psql('postgres', \$reindex_in, \$reindex_out,
$reindex_timer, on_error_stop => 1);
$reindex_in .= q(
\echo start
DROP INDEX CONCURRENTLY idx;
CREATE INDEX CONCURRENTLY idx ON tbl(i);
);
pump $reindex_h until $reindex_out =~ /start/ || $reindex_timer->is_expired;
$node->safe_psql('postgres', "COMMIT PREPARED 'spans_restart'");
$reindex_h->finish;
$result = $node->psql('postgres', q(SELECT bt_index_check('idx',true)));
is($result, '0', 'bt_index_check after 2PC and restart');
#
# Stress CIC+2PC with pgbench
#
# Fix broken index first
$node->safe_psql('postgres', q(REINDEX TABLE tbl;));
# Run background pgbench with CIC. We cannot mix-in this script into single
# pgbench: CIC will deadlock with itself occasionally.
my $pgbench_out = '';
my $pgbench_timer = IPC::Run::timeout(180);
my $pgbench_h = $node->background_pgbench(
'--no-vacuum --client=1 --transactions=100',
{
'002_pgbench_concurrent_cic' => q(
DROP INDEX CONCURRENTLY idx;
CREATE INDEX CONCURRENTLY idx ON tbl(i);
SELECT bt_index_check('idx',true);
)
},
\$pgbench_out,
$pgbench_timer);
# Run pgbench.
$node->pgbench(
'--no-vacuum --client=5 --transactions=100',
0,
[qr{actually processed}],
[qr{^$}],
'concurrent INSERTs w/ 2PC',
{
'002_pgbench_concurrent_2pc' => q(
BEGIN;
INSERT INTO tbl VALUES(0);
PREPARE TRANSACTION 'c:client_id';
COMMIT PREPARED 'c:client_id';
),
'002_pgbench_concurrent_2pc_savepoint' => q(
BEGIN;
SAVEPOINT s1;
INSERT INTO tbl VALUES(0);
PREPARE TRANSACTION 'c:client_id';
COMMIT PREPARED 'c:client_id';
)
});
$pgbench_h->pump_nb;
$pgbench_h->finish();
$result =
($Config{osname} eq "MSWin32")
? ($pgbench_h->full_results)[0]
: $pgbench_h->result(0);
is($result, 0, "pgbench with CIC works");
# done
$node->stop;
done_testing();