From 5c77690f6f419c504b7d8248db30c2280217e72e Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 26 Jun 2017 14:39:55 -0400 Subject: [PATCH] Improve wait logic in TAP tests for streaming replication. Remove hard-wired sleep(2) delays in 001_stream_rep.pl in favor of using poll_query_until to check for the desired state to appear. In addition, add such a wait before the last test in the script, as it's possible to demonstrate failures there after upcoming improvements in pg_ctl. (We might end up adding polling before each of the get_slot_xmins calls in this script, but I feel no great need to do that until shown necessary.) In passing, clarify the description strings for some of the test cases. Michael Paquier and Craig Ringer, pursuant to a complaint from me Discussion: https://postgr.es/m/8962.1498425057@sss.pgh.pa.us --- src/test/recovery/t/001_stream_rep.pl | 65 ++++++++++++++++++--------- 1 file changed, 45 insertions(+), 20 deletions(-) diff --git a/src/test/recovery/t/001_stream_rep.pl b/src/test/recovery/t/001_stream_rep.pl index 266d27c8a2..750e40c3da 100644 --- a/src/test/recovery/t/001_stream_rep.pl +++ b/src/test/recovery/t/001_stream_rep.pl @@ -146,6 +146,20 @@ $node_standby_2->append_conf('postgresql.conf', "wal_receiver_status_interval = 1"); $node_standby_2->restart; +# Wait for given condition on slot's pg_replication_slots row --- useful for +# ensuring we've reached a quiescent condition for reading slot xmins +sub wait_slot_xmins +{ + my ($node, $slot_name, $check_expr) = @_; + + $node->poll_query_until('postgres', qq[ + SELECT $check_expr + FROM pg_catalog.pg_replication_slots + WHERE slot_name = '$slot_name'; + ]); +} + +# Fetch xmin columns from slot's pg_replication_slots row sub get_slot_xmins { my ($node, $slotname) = @_; @@ -156,12 +170,12 @@ sub get_slot_xmins # There's no hot standby feedback and there are no logical slots on either peer # so xmin and catalog_xmin should be null on both slots. my ($xmin, $catalog_xmin) = get_slot_xmins($node_master, $slotname_1); -is($xmin, '', 'non-cascaded slot xmin null with no hs_feedback'); -is($catalog_xmin, '', 'non-cascaded slot xmin null with no hs_feedback'); +is($xmin, '', 'xmin of non-cascaded slot null with no hs_feedback'); +is($catalog_xmin, '', 'catalog xmin of non-cascaded slot null with no hs_feedback'); ($xmin, $catalog_xmin) = get_slot_xmins($node_standby_1, $slotname_2); -is($xmin, '', 'cascaded slot xmin null with no hs_feedback'); -is($catalog_xmin, '', 'cascaded slot xmin null with no hs_feedback'); +is($xmin, '', 'xmin of cascaded slot null with no hs_feedback'); +is($catalog_xmin, '', 'catalog xmin of cascaded slot null with no hs_feedback'); # Replication still works? $node_master->safe_psql('postgres', 'CREATE TABLE replayed(val integer);'); @@ -196,15 +210,18 @@ $node_standby_2->safe_psql('postgres', 'ALTER SYSTEM SET hot_standby_feedback = on;'); $node_standby_2->reload; replay_check(); -sleep(2); + +wait_slot_xmins($node_master, $slotname_1, + "xmin IS NOT NULL AND catalog_xmin IS NULL"); ($xmin, $catalog_xmin) = get_slot_xmins($node_master, $slotname_1); -isnt($xmin, '', 'non-cascaded slot xmin non-null with hs feedback'); -is($catalog_xmin, '', 'non-cascaded slot xmin still null with hs_feedback'); +isnt($xmin, '', 'xmin of non-cascaded slot non-null with hs feedback'); +is($catalog_xmin, '', + 'catalog xmin of non-cascaded slot still null with hs_feedback'); ($xmin, $catalog_xmin) = get_slot_xmins($node_standby_1, $slotname_2); -isnt($xmin, '', 'cascaded slot xmin non-null with hs feedback'); -is($catalog_xmin, '', 'cascaded slot xmin still null with hs_feedback'); +isnt($xmin, '', 'xmin of cascaded slot non-null with hs feedback'); +is($catalog_xmin, '', 'catalog xmin of cascaded slot still null with hs_feedback'); note "doing some work to advance xmin"; for my $i (10000 .. 11000) @@ -216,15 +233,15 @@ $node_master->safe_psql('postgres', 'CHECKPOINT;'); my ($xmin2, $catalog_xmin2) = get_slot_xmins($node_master, $slotname_1); note "new xmin $xmin2, old xmin $xmin"; -isnt($xmin2, $xmin, 'non-cascaded slot xmin with hs feedback has changed'); +isnt($xmin2, $xmin, 'xmin of non-cascaded slot with hs feedback has changed'); is($catalog_xmin2, '', - 'non-cascaded slot xmin still null with hs_feedback unchanged'); + 'catalog xmin of non-cascaded slot still null with hs_feedback unchanged'); ($xmin2, $catalog_xmin2) = get_slot_xmins($node_standby_1, $slotname_2); note "new xmin $xmin2, old xmin $xmin"; -isnt($xmin2, $xmin, 'cascaded slot xmin with hs feedback has changed'); +isnt($xmin2, $xmin, 'xmin of cascaded slot with hs feedback has changed'); is($catalog_xmin2, '', - 'cascaded slot xmin still null with hs_feedback unchanged'); + 'catalog xmin of cascaded slot still null with hs_feedback unchanged'); note "disabling hot_standby_feedback"; @@ -236,16 +253,22 @@ $node_standby_2->safe_psql('postgres', 'ALTER SYSTEM SET hot_standby_feedback = off;'); $node_standby_2->reload; replay_check(); -sleep(2); + +wait_slot_xmins($node_master, $slotname_1, + "xmin IS NULL AND catalog_xmin IS NULL"); ($xmin, $catalog_xmin) = get_slot_xmins($node_master, $slotname_1); -is($xmin, '', 'non-cascaded slot xmin null with hs feedback reset'); +is($xmin, '', 'xmin of non-cascaded slot null with hs feedback reset'); is($catalog_xmin, '', - 'non-cascaded slot xmin still null with hs_feedback reset'); + 'catalog xmin of non-cascaded slot still null with hs_feedback reset'); + +wait_slot_xmins($node_standby_1, $slotname_2, + "xmin IS NULL AND catalog_xmin IS NULL"); ($xmin, $catalog_xmin) = get_slot_xmins($node_standby_1, $slotname_2); -is($xmin, '', 'cascaded slot xmin null with hs feedback reset'); -is($catalog_xmin, '', 'cascaded slot xmin still null with hs_feedback reset'); +is($xmin, '', 'xmin of cascaded slot null with hs feedback reset'); +is($catalog_xmin, '', + 'catalog xmin of cascaded slot still null with hs_feedback reset'); note "re-enabling hot_standby_feedback and disabling while stopped"; $node_standby_2->safe_psql('postgres', @@ -260,11 +283,13 @@ $node_standby_2->safe_psql('postgres', $node_standby_2->stop; ($xmin, $catalog_xmin) = get_slot_xmins($node_standby_1, $slotname_2); -isnt($xmin, '', 'cascaded slot xmin non-null with postgres shut down'); +isnt($xmin, '', 'xmin of cascaded slot non-null with postgres shut down'); # Xmin from a previous run should be cleared on startup. $node_standby_2->start; +wait_slot_xmins($node_standby_1, $slotname_2, "xmin IS NULL"); + ($xmin, $catalog_xmin) = get_slot_xmins($node_standby_1, $slotname_2); is($xmin, '', - 'cascaded slot xmin reset after startup with hs feedback reset'); + 'xmin of cascaded slot reset after startup with hs feedback reset'); -- 2.40.0