pg.ddx.io pgsql-hackers@postgresql.org mailing list archive
help / color / mirror / Atom feed From: Tom Lane <tgl@sss.pgh.pa.us>
To: Michael Paquier <michael@paquier.xyz>
Cc: Andrew Dunstan <andrew@dunslane.net>
Cc: Mark Dilger <mark.dilger@enterprisedb.com>
Cc: Noah Misch <noah@leadboat.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Fixing WAL instability in various TAP tests
Date: Tue, 28 Sep 2021 14:11:04 -0400
Message-ID: <2854602.1632852664@sss.pgh.pa.us> (raw )
In-Reply-To: <2852500.1632850031@sss.pgh.pa.us >
References: <32A1FDD1-9C7B-43B1-B3EE-49198DD3F887@enterprisedb.com >
<20210925052151.GA4082552@rfd.leadboat.com >
<2E9D28A3-1B54-446B-AC12-3BF86A2B522A@enterprisedb.com >
<2502590.1632579467@sss.pgh.pa.us >
<2B4C64CF-EE3F-474B-9685-6A927E5E49AE@enterprisedb.com >
<20210925160039.GA4134968@rfd.leadboat.com >
<193AC968-C348-4D81-88BC-384560F87500@enterprisedb.com >
<C1D227C2-C271-4310-8C85-C5368C298622@enterprisedb.com >
<2769443.1632773967@sss.pgh.pa.us >
<YVJXEf119KrJDFdq@paquier.xyz >
<2801531.1632795612@sss.pgh.pa.us >
<2852500.1632850031@sss.pgh.pa.us >
I wrote:
> So there's more than one symptom, but in any case it seems like
> we have an issue in WAL replay. I wonder whether it's bloom's fault
> or a core bug.
Actually ... I bet it's just the test script's fault. It waits for the
standby to catch up like this:
my $caughtup_query =
"SELECT pg_current_wal_lsn() <= write_lsn FROM pg_stat_replication WHERE application_name = '$applname';";
$node_primary->poll_query_until('postgres', $caughtup_query)
or die "Timed out while waiting for standby 1 to catch up";
which seems like completely the wrong condition. Don't we need the
standby to have *replayed* the WAL, not merely written it to disk?
I'm also wondering why this doesn't use wait_for_catchup, instead
of reinventing the query to use.
regards, tom lane
view thread (25+ messages) latest in thread
Message-ID: <2854602.1632852664@sss.pgh.pa.us>
Permalink: ../2854602.1632852664@sss.pgh.pa.us/
Also on: postgresql.org/message-id/2854602.1632852664@sss.pgh.pa.us
copy link · copy postgr.es
reply Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, michael@paquier.xyz, andrew@dunslane.net, mark.dilger@enterprisedb.com, noah@leadboat.com
Subject: Re: Fixing WAL instability in various TAP tests
In-Reply-To: <2854602.1632852664@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox