From 0453e17be4e04c108f8989455ba069ab14242a17 Mon Sep 17 00:00:00 2001 From: Kyotaro Horiguchi Date: Thu, 21 Dec 2017 17:33:53 +0900 Subject: [PATCH 3/4] TAP test for the slot limit feature --- src/test/recovery/t/016_replslot_limit.pl | 174 ++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 src/test/recovery/t/016_replslot_limit.pl diff --git a/src/test/recovery/t/016_replslot_limit.pl b/src/test/recovery/t/016_replslot_limit.pl new file mode 100644 index 0000000000..f5a87b6617 --- /dev/null +++ b/src/test/recovery/t/016_replslot_limit.pl @@ -0,0 +1,174 @@ +# Test for replication slot limit +# Ensure that max_slot_wal_keep_size limits the number of WAL files to +# be kept by replication slot. + +use strict; +use warnings; +use File::Path qw(rmtree); +use PostgresNode; +use TestLib; +use Test::More tests => 9; +use Time::HiRes qw(usleep); + +$ENV{PGDATABASE} = 'postgres'; + +# Initialize master node +my $node_master = get_new_node('master'); +$node_master->init(allows_streaming => 1); +$node_master->append_conf('postgresql.conf', qq( +min_wal_size = 32MB +max_wal_size = 48MB +)); +$node_master->start; +$node_master->safe_psql('postgres', "SELECT pg_create_physical_replication_slot('rep1')"); + + +# Take backup +my $backup_name = 'my_backup'; +$node_master->backup($backup_name); + +# Create a standby linking to it using a replication slot +my $node_standby = get_new_node('standby_1'); +$node_standby->init_from_backup($node_master, $backup_name, has_streaming => 1, primary_slot_name => 'rep1'); +$node_standby->append_conf('recovery.conf', qq( +primary_slot_name = 'rep1' +)); +$node_standby->start; + +# Wait until standby has replayed enough data on the standby +my $start_lsn = $node_master->lsn('write'); +$node_master->wait_for_catchup($node_standby, 'replay', $start_lsn); + +# Stop standby +$node_standby->stop; + + +# Preparation done, currently the slot must be secured. +my $result = $node_master->safe_psql('postgres', "SELECT restart_lsn, wal_status, remain FROM pg_replication_slots WHERE slot_name = 'rep1'"); +is($result, "$start_lsn|streaming|0", 'check initial state of standby'); + +# Advance WAL by ten segments (= 160MB) on master +advance_wal($node_master, 10); +$node_master->safe_psql('postgres', "CHECKPOINT;"); + +# The slot is unconditionally "safe" with the default setting. +$result = $node_master->safe_psql('postgres', "SELECT restart_lsn, wal_status, remain FROM pg_replication_slots WHERE slot_name = 'rep1'"); +is($result, "$start_lsn|streaming|0", 'check that slot is keeping all segments'); + +# The stanby can connect to master +$node_standby->start; + +$start_lsn = $node_master->lsn('write'); +$node_master->wait_for_catchup($node_standby, 'replay', $start_lsn); + +$node_standby->stop; + + +# Set max_slot_wal_keep_size on master +my $max_slot_wal_keep_size_mb = 48; +$node_master->append_conf('postgresql.conf', qq( +max_slot_wal_keep_size = ${max_slot_wal_keep_size_mb}MB +)); +$node_master->reload; + +# The slot is in safe state. +$result = $node_master->safe_psql('postgres', "SELECT restart_lsn, wal_status, pg_size_pretty(remain) as remain FROM pg_replication_slots WHERE slot_name = 'rep1'"); +is($result, "$start_lsn|streaming|64 MB", 'check that remaining byte is calculated'); + +# Advance WAL again then checkpoint +advance_wal($node_master, 2); +$node_master->safe_psql('postgres', "CHECKPOINT;"); + +# The slot is still working. +$result = $node_master->safe_psql('postgres', "SELECT restart_lsn, wal_status, pg_size_pretty(remain) as remain FROM pg_replication_slots WHERE slot_name = 'rep1'"); +is($result, "$start_lsn|streaming|32 MB", 'remaining byte should be reduced by 32MB'); + +# Advance WAL again without checkpoint +advance_wal($node_master, 2); + +# Slot gets to 'keeping' state +$result = $node_master->safe_psql('postgres', "SELECT restart_lsn, wal_status, pg_size_pretty(remain) as remain FROM pg_replication_slots WHERE slot_name = 'rep1'"); +is($result, "$start_lsn|keeping|0 bytes", 'check that some segments are about to removed'); + +# The stanby still can connect to master +$node_standby->start; + +$start_lsn = $node_master->lsn('write'); +$node_master->wait_for_catchup($node_standby, 'replay', $start_lsn); + +$node_standby->stop; + +ok(!find_in_log($node_standby, + "requested WAL segment [0-9A-F]+ has already been removed"), + 'check that no replication failure is caused by insecure state'); + +# Advance WAL again, the slot loses some segments. +my $logstart = get_log_size($node_master); +advance_wal($node_master, 10); +$node_master->safe_psql('postgres', "CHECKPOINT;"); + +# WARNING should be issued +ok(find_in_log($node_master, + "some replication slots have lost required WAL segments\n". + ".*The mostly affected slot has lost 5 segments.", + $logstart), + 'check that warning is correctly logged'); + +# This slot should be broken +$result = $node_master->safe_psql('postgres', "SELECT restart_lsn, wal_status, pg_size_pretty(remain) as remain FROM pg_replication_slots WHERE slot_name = 'rep1'"); +is($result, "$start_lsn|lost|0 bytes", 'check that overflown segments have been removed'); + +# The stanby no longer can connect to the master +$logstart = get_log_size($node_standby); +$node_standby->start; + +my $failed = 0; +for (my $i = 0 ; $i < 10000 ; $i++) +{ + if (find_in_log($node_standby, + "requested WAL segment [0-9A-F]+ has already been removed", + $logstart)) + { + $failed = 1; + last; + } + usleep(100_000); +} +ok($failed, 'check that replication has been broken'); + +$node_standby->stop; + +##################################### +# Advance WAL of $node by $n segments +sub advance_wal +{ + my ($node, $n) = @_; + + # Advance by $n segments (= (16 * $n) MB) on master + for (my $i = 0 ; $i < $n ; $i++) + { + $node->safe_psql('postgres', "CREATE TABLE t (a int); DROP TABLE t; SELECT pg_switch_wal();"); + } +} + +# return the size of logfile of $node in bytes +sub get_log_size +{ + my ($node) = @_; + + return (stat $node->logfile)[7]; +} + +# find $pat in logfile of $node after $off-th byte +sub find_in_log +{ + my ($node, $pat, $off) = @_; + + $off = 0 unless defined $off; + my $log = TestLib::slurp_file($node->logfile); + return 0 if (length($log) <= $off); + + $log = substr($log, $off); + + return $log =~ m/$pat/; +} -- 2.16.3