+++ /dev/null
-use strict;
-use warnings;
-use PostgreSQL::Test::Cluster;
-use Test::More;
-
-# Test that vacuum prunes away all dead tuples killed before OldestXmin
-#
-# This test creates a table on a primary, updates the table to generate dead
-# tuples for vacuum, and then, during the vacuum, uses the replica to force
-# GlobalVisState->maybe_needed on the primary to move backwards and precede
-# the value of OldestXmin set at the beginning of vacuuming the table.
-
-# Set up nodes
-my $node_primary = PostgreSQL::Test::Cluster->new('primary');
-$node_primary->init(allows_streaming => 'physical');
-
-$node_primary->append_conf(
- 'postgresql.conf', qq[
-hot_standby_feedback = on
-log_recovery_conflict_waits = true
-autovacuum = off
-log_min_messages = INFO
-maintenance_work_mem = 1024
-]);
-$node_primary->start;
-
-my $node_replica = PostgreSQL::Test::Cluster->new('standby');
-
-$node_primary->backup('my_backup');
-$node_replica->init_from_backup($node_primary, 'my_backup',
- has_streaming => 1);
-
-$node_replica->start;
-
-my $test_db = "test_db";
-$node_primary->safe_psql('postgres', "CREATE DATABASE $test_db");
-
-# Save the original connection info for later use
-my $orig_conninfo = $node_primary->connstr();
-
-my $table1 = "vac_horizon_floor_table";
-
-# Long-running Primary Session A
-my $psql_primaryA =
- $node_primary->background_psql($test_db, on_error_stop => 1);
-
-# Long-running Primary Session B
-my $psql_primaryB =
- $node_primary->background_psql($test_db, on_error_stop => 1);
-
-# The TIDStore vacuum uses to store dead items is optimized for its target
-# system. On a 32-bit system, our example requires twice as many pages with
-# the same number of dead items per page to fill the TIDStore and trigger a
-# second round of index vacuuming.
-my $is_64bit = $node_primary->safe_psql($test_db,
- qq[SELECT typbyval FROM pg_type WHERE typname = 'int8';]);
-
-my $nrows = $is_64bit eq 't' ? 400000 : 800000;
-
-# Because vacuum's first pass, pruning, is where we use the GlobalVisState to
-# check tuple visibility, GlobalVisState->maybe_needed must move backwards
-# during pruning before checking the visibility for a tuple which would have
-# been considered HEAPTUPLE_DEAD prior to maybe_needed moving backwards but
-# HEAPTUPLE_RECENTLY_DEAD compared to the new, older value of maybe_needed.
-#
-# We must not only force the horizon on the primary to move backwards but also
-# force the vacuuming backend's GlobalVisState to be updated. GlobalVisState
-# is forced to update during index vacuuming.
-#
-# _bt_pendingfsm_finalize() calls GetOldestNonRemovableTransactionId() at the
-# end of a round of index vacuuming, updating the backend's GlobalVisState
-# and, in our case, moving maybe_needed backwards.
-#
-# Then vacuum's first (pruning) pass will continue and pruning will find our
-# later inserted and updated tuple HEAPTUPLE_RECENTLY_DEAD when compared to
-# maybe_needed but HEAPTUPLE_DEAD when compared to OldestXmin.
-#
-# Thus, we must force at least two rounds of index vacuuming to ensure that
-# some tuple visibility checks will happen after a round of index vacuuming.
-# To accomplish this, we set maintenance_work_mem to its minimum value and
-# insert and update enough rows that we force at least one round of index
-# vacuuming before getting to a dead tuple which was killed after the standby
-# is disconnected.
-$node_primary->safe_psql($test_db, qq[
- CREATE TABLE ${table1}(col1 int)
- WITH (autovacuum_enabled=false, fillfactor=10);
- INSERT INTO $table1 VALUES(7);
- INSERT INTO $table1 SELECT generate_series(1, $nrows) % 3;
- CREATE INDEX on ${table1}(col1);
- UPDATE $table1 SET col1 = 3 WHERE col1 = 0;
- INSERT INTO $table1 VALUES(7);
-]);
-
-# We will later move the primary forward while the standby is disconnected.
-# For now, however, there is no reason not to wait for the standby to catch
-# up.
-my $primary_lsn = $node_primary->lsn('flush');
-$node_primary->wait_for_catchup($node_replica, 'replay', $primary_lsn);
-
-# Test that the WAL receiver is up and running.
-$node_replica->poll_query_until($test_db, qq[
- select exists (select * from pg_stat_wal_receiver);] , 't');
-
-# Set primary_conninfo to something invalid on the replica and reload the
-# config. Once the config is reloaded, the startup process will force the WAL
-# receiver to restart and it will be unable to reconnect because of the
-# invalid connection information.
-$node_replica->safe_psql($test_db, qq[
- ALTER SYSTEM SET primary_conninfo = '';
- SELECT pg_reload_conf();
- ]);
-
-# Wait until the WAL receiver has shut down and been unable to start up again.
-$node_replica->poll_query_until($test_db, qq[
- select exists (select * from pg_stat_wal_receiver);] , 'f');
-
-# Now insert and update a tuple which will be visible to the vacuum on the
-# primary but which will have xmax newer than the oldest xmin on the standby
-# that was recently disconnected.
-my $res = $psql_primaryA->query_safe(
- qq[
- INSERT INTO $table1 VALUES (99);
- UPDATE $table1 SET col1 = 100 WHERE col1 = 99;
- SELECT 'after_update';
- ]
- );
-
-# Make sure the UPDATE finished
-like($res, qr/^after_update$/m, "UPDATE occurred on primary session A");
-
-# Open a cursor on the primary whose pin will keep VACUUM from getting a
-# cleanup lock on the first page of the relation. We want VACUUM to be able to
-# start, calculate initial values for OldestXmin and GlobalVisState and then
-# be unable to proceed with pruning our dead tuples. This will allow us to
-# reconnect the standby and push the horizon back before we start actual
-# pruning and vacuuming.
-my $primary_cursor1 = "vac_horizon_floor_cursor1";
-
-# The first value inserted into the table was a 7, so FETCH FORWARD should
-# return a 7. That's how we know the cursor has a pin.
-$res = $psql_primaryB->query_safe(
- qq[
- BEGIN;
- DECLARE $primary_cursor1 CURSOR FOR SELECT * FROM $table1 WHERE col1 = 7;
- FETCH $primary_cursor1;
- ]
- );
-
-is($res, 7, qq[Cursor query returned $res. Expected value 7.]);
-
-# Get the PID of the session which will run the VACUUM FREEZE so that we can
-# use it to filter pg_stat_activity later.
-my $vacuum_pid = $psql_primaryA->query_safe("SELECT pg_backend_pid();");
-
-# Now start a VACUUM FREEZE on the primary. It will call vacuum_get_cutoffs()
-# and establish values of OldestXmin and GlobalVisState which are newer than
-# all of our dead tuples. Then it will be unable to get a cleanup lock to
-# start pruning, so it will hang.
-#
-# We use VACUUM FREEZE because it will wait for a cleanup lock instead of
-# skipping the page pinned by the cursor. Note that works because the target
-# tuple's xmax precedes OldestXmin which ensures that lazy_scan_noprune() will
-# return false and we will wait for the cleanup lock.
-$psql_primaryA->{stdin} .= qq[
- VACUUM (VERBOSE, FREEZE) $table1;
- \\echo VACUUM
- ];
-
-# Make sure the VACUUM command makes it to the server.
-$psql_primaryA->{run}->pump_nb();
-
-# Make sure that the VACUUM has already called vacuum_get_cutoffs() and is
-# just waiting on the lock to start vacuuming. We don't want the standby to
-# re-establish a connection to the primary and push the horizon back until
-# we've saved initial values in GlobalVisState and calculated OldestXmin.
-$node_primary->poll_query_until($test_db,
- qq[
- SELECT count(*) >= 1 FROM pg_stat_activity
- WHERE pid = $vacuum_pid
- AND wait_event = 'BufferPin';
- ],
- 't');
-
-# Ensure the WAL receiver is still not active on the replica.
-$node_replica->poll_query_until($test_db, qq[
- SELECT EXISTS (SELECT * FROM pg_stat_wal_receiver);] , 'f');
-
-# Allow the WAL receiver connection to re-establish.
-$node_replica->safe_psql(
- $test_db, qq[
- ALTER SYSTEM SET primary_conninfo = '$orig_conninfo';
- SELECT pg_reload_conf();
- ]);
-
-# Ensure the new WAL receiver has connected.
-$node_replica->poll_query_until($test_db, qq[
- SELECT EXISTS (SELECT * FROM pg_stat_wal_receiver);] , 't');
-
-# Once the WAL sender is shown on the primary, the replica should have
-# connected with the primary and pushed the horizon backward. Primary Session
-# A won't see that until the VACUUM FREEZE proceeds and does its first round
-# of index vacuuming.
-$node_primary->poll_query_until($test_db, qq[
- SELECT EXISTS (SELECT * FROm pg_stat_replication);] , 't');
-
-# Move the cursor forward to the next 7. We inserted the 7 much later, so
-# advancing the cursor should allow vacuum to proceed vacuuming most pages of
-# the relation. Because we set maintanence_work_mem sufficiently low, we
-# expect that a round of index vacuuming has happened and that the vacuum is
-# now waiting for the cursor to release its pin on the last page of the
-# relation.
-$res = $psql_primaryB->query_safe("FETCH $primary_cursor1");
-is($res, 7,
- qq[Cursor query returned $res from second fetch. Expected value 7.]);
-
-# Prevent the test from incorrectly passing by confirming that we did indeed
-# do a pass of index vacuuming.
-$node_primary->poll_query_until($test_db, qq[
- SELECT index_vacuum_count > 0
- FROM pg_stat_progress_vacuum
- WHERE datname='$test_db' AND relid::regclass = '$table1'::regclass;
- ] , 't');
-
-# Commit the transaction with the open cursor so that the VACUUM can finish.
-$psql_primaryB->query_until(
- qr/^commit$/m,
- qq[
- COMMIT;
- \\echo commit
- ]
- );
-
-# VACUUM proceeds with pruning and does a visibility check on each tuple. In
-# older versions of Postgres, pruning found our final dead tuple
-# non-removable (HEAPTUPLE_RECENTLY_DEAD) since its xmax is after the new
-# value of maybe_needed. Then heap_prepare_freeze_tuple() would decide the
-# tuple xmax should be frozen because it precedes OldestXmin. Vacuum would
-# then error out in heap_pre_freeze_checks() with "cannot freeze committed
-# xmax". This was fixed by changing pruning to find all
-# HEAPTUPLE_RECENTLY_DEAD tuples with xmaxes preceding OldestXmin
-# HEAPTUPLE_DEAD and removing them.
-
-# With the fix, VACUUM should finish successfully, incrementing the table
-# vacuum_count.
-$node_primary->poll_query_until($test_db,
- qq[
- SELECT vacuum_count > 0
- FROM pg_stat_all_tables WHERE relname = '${table1}';
- ]
- , 't');
-
-$primary_lsn = $node_primary->lsn('flush');
-
-# Make sure something causes us to flush
-$node_primary->safe_psql($test_db, "INSERT INTO $table1 VALUES (1);");
-
-# Nothing on the replica should cause a recovery conflict, so this should
-# finish successfully.
-$node_primary->wait_for_catchup($node_replica, 'replay', $primary_lsn);
-
-## Shut down psqls
-$psql_primaryA->quit;
-$psql_primaryB->quit;
-
-$node_replica->stop();
-$node_primary->stop();
-
-done_testing();
projects / postgresql.git / commitdiff