diff options
Diffstat (limited to 'src/test/recovery/t/010_logical_decoding_timelines.pl')
| -rw-r--r-- | src/test/recovery/t/010_logical_decoding_timelines.pl | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/src/test/recovery/t/010_logical_decoding_timelines.pl b/src/test/recovery/t/010_logical_decoding_timelines.pl new file mode 100644 index 00000000000..09830dc39ce --- /dev/null +++ b/src/test/recovery/t/010_logical_decoding_timelines.pl @@ -0,0 +1,130 @@ +# Demonstrate that logical can follow timeline switches. +# +# Logical replication slots can follow timeline switches but it's +# normally not possible to have a logical slot on a replica where +# promotion and a timeline switch can occur. The only ways +# we can create that circumstance are: +# +# * By doing a filesystem-level copy of the DB, since pg_basebackup +# excludes pg_replslot but we can copy it directly; or +# +# * by creating a slot directly at the C level on the replica and +# advancing it as we go using the low level APIs. It can't be done +# from SQL since logical decoding isn't allowed on replicas. +# +# This module uses the first approach to show that timeline following +# on a logical slot works. +# +use strict; +use warnings; + +use PostgresNode; +use TestLib; +use Test::More tests => 7; +use RecursiveCopy; +use File::Copy; +use IPC::Run (); +use Scalar::Util qw(blessed); + +my ($stdout, $stderr, $ret); + +# Initialize master node +my $node_master = get_new_node('master'); +$node_master->init(allows_streaming => 1, has_archiving => 1); +$node_master->append_conf('postgresql.conf', "wal_level = 'logical'\n"); +$node_master->append_conf('postgresql.conf', "max_replication_slots = 2\n"); +$node_master->append_conf('postgresql.conf', "max_wal_senders = 2\n"); +$node_master->append_conf('postgresql.conf', "log_min_messages = 'debug2'\n"); +$node_master->dump_info; +$node_master->start; + +diag "Testing logical timeline following with a filesystem-level copy"; + +$node_master->safe_psql('postgres', +"SELECT pg_create_logical_replication_slot('before_basebackup', 'test_decoding');" +); +$node_master->safe_psql('postgres', "CREATE TABLE decoding(blah text);"); +$node_master->safe_psql('postgres', + "INSERT INTO decoding(blah) VALUES ('beforebb');"); +$node_master->safe_psql('postgres', 'CHECKPOINT;'); + +my $backup_name = 'b1'; +$node_master->backup_fs_hot($backup_name); + +my $node_replica = get_new_node('replica'); +$node_replica->init_from_backup( + $node_master, $backup_name, + has_streaming => 1, + has_restoring => 1); +$node_replica->start; + +$node_master->safe_psql('postgres', +"SELECT pg_create_logical_replication_slot('after_basebackup', 'test_decoding');" +); +$node_master->safe_psql('postgres', + "INSERT INTO decoding(blah) VALUES ('afterbb');"); +$node_master->safe_psql('postgres', 'CHECKPOINT;'); + +# Verify that only the before base_backup slot is on the replica +$stdout = $node_replica->safe_psql('postgres', + 'SELECT slot_name FROM pg_replication_slots ORDER BY slot_name'); +is($stdout, 'before_basebackup', + 'Expected to find only slot before_basebackup on replica'); + +# Boom, crash +$node_master->stop('immediate'); + +$node_replica->promote; +$node_replica->poll_query_until('postgres', + "SELECT NOT pg_is_in_recovery();"); + +$node_replica->safe_psql('postgres', + "INSERT INTO decoding(blah) VALUES ('after failover');"); + +# Shouldn't be able to read from slot created after base backup +($ret, $stdout, $stderr) = $node_replica->psql('postgres', +"SELECT data FROM pg_logical_slot_peek_changes('after_basebackup', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');" +); +is($ret, 3, 'replaying from after_basebackup slot fails'); +like( + $stderr, + qr/replication slot "after_basebackup" does not exist/, + 'after_basebackup slot missing'); + +# Should be able to read from slot created before base backup +($ret, $stdout, $stderr) = $node_replica->psql( + 'postgres', +"SELECT data FROM pg_logical_slot_peek_changes('before_basebackup', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');", + timeout => 30); +is($ret, 0, 'replay from slot before_basebackup succeeds'); + +my $final_expected_output_bb = q(BEGIN +table public.decoding: INSERT: blah[text]:'beforebb' +COMMIT +BEGIN +table public.decoding: INSERT: blah[text]:'afterbb' +COMMIT +BEGIN +table public.decoding: INSERT: blah[text]:'after failover' +COMMIT); +is($stdout, $final_expected_output_bb, 'decoded expected data from slot before_basebackup'); +is($stderr, '', 'replay from slot before_basebackup produces no stderr'); + +# So far we've peeked the slots, so when we fetch the same info over +# pg_recvlogical we should get complete results. First, find out the commit lsn +# of the last transaction. There's no max(pg_lsn), so: + +my $endpos = $node_replica->safe_psql('postgres', "SELECT location FROM pg_logical_slot_peek_changes('before_basebackup', NULL, NULL) ORDER BY location DESC LIMIT 1;"); + +# now use the walsender protocol to peek the slot changes and make sure we see +# the same results. + +$stdout = $node_replica->pg_recvlogical_upto('postgres', 'before_basebackup', + $endpos, 30, 'include-xids' => '0', 'skip-empty-xacts' => '1'); + +# walsender likes to add a newline +chomp($stdout); +is($stdout, $final_expected_output_bb, 'got same output from walsender via pg_recvlogical on before_basebackup'); + +# We don't need the standby anymore +$node_replica->teardown_node(); |