From 4576a69354fa2efc1bafa50df1c104c1a80c64e5 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 8 Aug 2017 18:03:30 -0400 Subject: [PATCH] Fix yet another race condition in recovery/t/001_stream_rep.pl. In commit 5c77690f6, we added polling in front of most of the get_slot_xmins calls in 001_stream_rep.pl, but today's results from buildfarm member nightjar show that at least one more poll loop is needed. Proactively add a poll loop before the next-to-last get_slot_xmins call as well. It may be that there is no race condition there because the standby_2 server is shut down at that point, but I'm quite tired of fighting with this test script. The empirical evidence that it's safe, from the buildfarm, is no stronger than the evidence for the other call that nightjar just proved unsafe. The only remaining get_slot_xmins calls without wait_slot_xmins protection are the first two, which should be OK since nothing has happened at that point. It's tempting to ignore that special case and merge get_slot_xmins and wait_slot_xmins into a single function. I didn't go that far though. Discussion: https://postgr.es/m/18436.1502228036@sss.pgh.pa.us --- src/test/recovery/t/001_stream_rep.pl | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/test/recovery/t/001_stream_rep.pl b/src/test/recovery/t/001_stream_rep.pl index 3590516425..840af66f75 100644 --- a/src/test/recovery/t/001_stream_rep.pl +++ b/src/test/recovery/t/001_stream_rep.pl @@ -220,9 +220,13 @@ 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'); +wait_slot_xmins($node_standby_1, $slotname_2, + "xmin IS NOT NULL AND catalog_xmin IS NULL"); + my ($xmin1, $catalog_xmin1) = get_slot_xmins($node_standby_1, $slotname_2); isnt($xmin1, '', 'xmin of cascaded slot non-null with hs feedback'); -is($catalog_xmin1, '', 'catalog xmin of cascaded slot still null with hs_feedback'); +is($catalog_xmin1, '', + 'catalog xmin of cascaded slot still null with hs_feedback'); note "doing some work to advance xmin"; $node_master->safe_psql('postgres', q{ @@ -297,6 +301,8 @@ $node_standby_2->safe_psql('postgres', 'ALTER SYSTEM SET hot_standby_feedback = off;'); $node_standby_2->stop; +wait_slot_xmins($node_standby_1, $slotname_2, "xmin IS NOT NULL"); + ($xmin, $catalog_xmin) = get_slot_xmins($node_standby_1, $slotname_2); isnt($xmin, '', 'xmin of cascaded slot non-null with postgres shut down'); -- 2.40.0