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

help / color / mirror / Atom feed
From: Justin Pryzby <pryzby@telsasoft.com>
To: Andres Freund <andres@anarazel.de>
Cc: Melanie Plageman <melanieplageman@gmail.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: tgl@sss.pgh.pa.us
Cc: vignesh21@gmail.com
Cc: lukas@fittl.com
Cc: alvherre@alvh.no-ip.org
Cc: magnus@hagander.net
Cc: pgsql-hackers@postgresql.org
Cc: thomas.munro@gmail.com
Cc: m.sakrejda@gmail.com
Subject: Re: pg_stat_bgwriter.buffers_backend is pretty meaningless (and more?)
Date: Thu, 9 Mar 2023 06:51:31 -0600
Message-ID: <ZAnWU8WbXEDjrfUE@telsasoft.com> (raw)
In-Reply-To: <20230307181844.hxnlfi3wa5lm7sm2@awork3.anarazel.de>
References: <20230211182437.ype5tk3awen2htvw@awork3.anarazel.de>
	<3039228.1677972069@sss.pgh.pa.us>
	<20230306.152425.316894602450485455.horikyota.ntt@gmail.com>
	<20230306.154843.178021884584228317.horikyota.ntt@gmail.com>
	<CAAKRu_ZRKp-zDCSVk9p8XE=ZKTn3WiJD6Mt=n=eSPQ7Kg-=HRw@mail.gmail.com>
	<20230306190919.ai6mxdq3sygyyths@awork3.anarazel.de>
	<20230306192409.daz5ivq4mbbr2ye7@liskov>
	<20230306193404.3btuacgc6um33mt2@awork3.anarazel.de>
	<CAAKRu_ZmAhCGzk2GkNeMHTu0Oh=rtNKU7Q+fkzLs-PZBp1sicg@mail.gmail.com>
	<20230307181844.hxnlfi3wa5lm7sm2@awork3.anarazel.de>

On Tue, Mar 07, 2023 at 10:18:44AM -0800, Andres Freund wrote:
> Hi,
> 
> On 2023-03-06 15:21:14 -0500, Melanie Plageman wrote:
> > Good point. Attached is what you suggested. I committed the transaction
> > before the drop table so that the statistics would be visible when we
> > queried pg_stat_io.
> 
> Pushed, thanks for the report, analysis and fix, Tom, Horiguchi-san, Melanie.

There's a 2nd portion of the test that's still flapping, at least on
cirrusci.

The issue that Tom mentioned is at:
 SELECT :io_sum_shared_after_writes > :io_sum_shared_before_writes;

But what I've seen on cirrusci is at:
 SELECT :io_sum_shared_after_writes > :io_sum_shared_before_writes;

https://api.cirrus-ci.com/v1/artifact/task/6701069548388352/log/src/test/recovery/tmp_check/regressi...
https://api.cirrus-ci.com/v1/artifact/task/5355168397524992/log/src/test/recovery/tmp_check/regressi...
https://api.cirrus-ci.com/v1/artifact/task/6142435751886848/testrun/build/testrun/recovery/027_strea...

It'd be neat if cfbot could show a histogram of test failures, although
I'm not entirely sure what granularity would be most useful: the test
that failed (027_regress) or the way it failed (:after_write >
:before_writes).  Maybe it's enough to show the test, with links to its
recent failures.

-- 
Justin





view thread (173+ messages)  latest in thread

Message-ID: <ZAnWU8WbXEDjrfUE@telsasoft.com>
Permalink:  ../ZAnWU8WbXEDjrfUE@telsasoft.com/
Also on:    postgresql.org/message-id/ZAnWU8WbXEDjrfUE@telsasoft.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: pryzby@telsasoft.com, andres@anarazel.de, melanieplageman@gmail.com, horikyota.ntt@gmail.com, tgl@sss.pgh.pa.us, vignesh21@gmail.com, lukas@fittl.com, alvherre@alvh.no-ip.org, magnus@hagander.net, thomas.munro@gmail.com, m.sakrejda@gmail.com
  Subject: Re: pg_stat_bgwriter.buffers_backend is pretty meaningless (and more?)
  In-Reply-To: <ZAnWU8WbXEDjrfUE@telsasoft.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