Re: Intermittent buildfarm failures on wrasse

From: Andres Freund <andres(at)anarazel(dot)de>
To: Peter Geoghegan <pg(at)bowt(dot)ie>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Noah Misch <noah(at)leadboat(dot)com>, David Rowley <dgrowleyml(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: Intermittent buildfarm failures on wrasse
Date: 2022-04-15 17:43:22
Message-ID: 20220415174322.cjandijzmxhx5fuv@alap3.anarazel.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Hi,

On 2022-04-15 10:23:56 -0700, Peter Geoghegan wrote:
> On Fri, Apr 15, 2022 at 10:15 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > > As well as the age of OldestXmin at the start of VACUUM.
> >
> > Is it worth capturing and logging both of those numbers? Why is
> > the age at the end more interesting than the age at the start?
>
> As Andres said, that's often more interesting because most of the time
> OldestXmin is not held back by much (not enough to matter).

I think it'd be interesting - particularly for large relations or when
looking to adjust autovac cost limits. It's not rare for autovac to take
long enough that another autovac is necessary immediately again. Also
helps to interpret the "dead but not yet removable" counts.

Something like:
removable cutoff: %u, age at start: %u, age at end: %u...

Greetings,

Andres Freund

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Peter Geoghegan 2022-04-15 18:12:34 Re: Intermittent buildfarm failures on wrasse
Previous Message Tom Lane 2022-04-15 17:28:35 Crash in new pgstats code