pg.ddx.io  pgsql-hackers@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Alexander Lakhin <exclusion@gmail.com>
To: Noah Misch <noah@leadboat.com>
Cc: pgsql-hackers@postgresql.org
Subject: Re: race condition in pg_class
Date: Sat, 20 Jul 2024 11:00:00 +0300
Message-ID: <e3fa725b-474c-c155-6a0d-5c97cbfbdc4a@gmail.com> (raw)
In-Reply-To: <20240628051353.a0.nmisch@google.com>
References: <20231027214946.79.nmisch@google.com>
	<1617596.1698446455@sss.pgh.pa.us>
	<20231027232612.99.nmisch@google.com>
	<20231102030915.d3.nmisch@google.com>
	<20240512232923.aa.nmisch@google.com>
	<20240605181706.fe.nmisch@google.com>
	<CA+TgmobfMU5pdXP36D5iAwxV5WKE_vuDLtp_1QyH+H5jMMt21g@mail.gmail.com>
	<20240611024525.9f.nmisch@google.com>
	<20240614003549.c2.nmisch@google.com>
	<20240621212842.98.nmisch@google.com>
	<20240628051353.a0.nmisch@google.com>

Hello Noah,

28.06.2024 08:13, Noah Misch wrote:
> Pushed.

A recent buildfarm test failure [1] showed that the
intra-grant-inplace-db.spec test added with 0844b3968 may fail
on a slow machine (per my understanding):

test intra-grant-inplace-db       ... FAILED     4302 ms

@@ -21,8 +21,7 @@
      WHERE datname = current_catalog
          AND age(datfrozenxid) > (SELECT min(age(x)) FROM frozen_witness);

-?column?
-----------------------
-datfrozenxid retreated
-(1 row)
+?column?
+--------
+(0 rows)

whilst the previous (successful) run shows much shorter duration:
test intra-grant-inplace-db       ... ok          540 ms

I reproduced this failure on a VM slowed down so that the test duration
reached 4+ seconds, with 100 test: intra-grant-inplace-db in
isolation_schedule:
test intra-grant-inplace-db       ... ok         4324 ms
test intra-grant-inplace-db       ... FAILED     4633 ms
test intra-grant-inplace-db       ... ok         4649 ms

But as the test going to be modified by the inplace110-successors-v8.patch
and the modified test (with all three latest patches applied) passes
reliably in the same conditions, maybe this failure doesn't deserve a
deeper exploration.

What do you think?

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=habu&dt=2024-07-18%2003%3A08%3A08

Best regards,
Alexander





view thread (86+ messages)  latest in thread

Message-ID: <e3fa725b-474c-c155-6a0d-5c97cbfbdc4a@gmail.com>
Permalink:  ../e3fa725b-474c-c155-6a0d-5c97cbfbdc4a@gmail.com/
Also on:    postgresql.org/message-id/e3fa725b-474c-c155-6a0d-5c97cbfbdc4a@gmail.com

 · 

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: exclusion@gmail.com, noah@leadboat.com
  Subject: Re: race condition in pg_class
  In-Reply-To: <e3fa725b-474c-c155-6a0d-5c97cbfbdc4a@gmail.com>

* 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