public inbox for [email protected]  

help / color / mirror / Atom feed

From: Bertrand Drouvot <[email protected]>
To: Nazir Bilal Yavuz <[email protected]>
Cc: Michael Paquier <[email protected]>
Cc: Alvaro Herrera <[email protected]>
Cc: Kyotaro Horiguchi <[email protected]>
Cc: [email protected]
Cc: Andres Freund <[email protected]>
Subject: Re: per backend I/O statistics
Date: Wed, 15 Jan 2025 16:00:12 +0000
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAN55FZ1uOq=FVJObp0bdj-Z8q1ZRNmA-RymPqbMD+p4QaHXP3A@mail.gmail.com>
References: <[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<CAN55FZ0ZQTf-D+5Rup4H6zp+n3E2EuonYuzTiPkp=1GhesZU_A@mail.gmail.com>
	<[email protected]>
	<[email protected]>
	<CAN55FZ1uOq=FVJObp0bdj-Z8q1ZRNmA-RymPqbMD+p4QaHXP3A@mail.gmail.com>

Hi,

On Wed, Jan 15, 2025 at 05:20:57PM +0300, Nazir Bilal Yavuz wrote:
> While doing the initdb, we are restoring stats with the
> pgstat_restore_stats() and we do not expect any pending stats. The
> problem goes like that:
> 
> I was a bit surprised that Bertrand did not encounter the same problem
> while working on the 'per backend WAL statistics' patch. Then I found
> the reason, it is because this problem happens only for WAL read and
> WAL init IOs which are starting to be tracked in my patch. By saying
> that, I could not decide which thread to write about this problem,
> migrating WAL stats thread or this thread. Since this thread is active
> and other stats may cause the same problem, I decided to write here.
> Please warn me if you think I need to write this to the migrating WAL
> stats thread.

Thanks for the report! As it looks like that you hit the issue for "WAL read and
WAL init IOs which are starting to be tracked in my patch", then I think it would
make more sense to mention the issue in the "migrating WAL stats thread" so that
one could try to reproduce it (with a patch producing the issue at hands).

So it seems to me that the "migrating WAL stats thread" is a better place to
discuss about it.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com

view thread (39+ messages)  latest in thread

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: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: per backend I/O statistics
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox