Feedback-ID: i0fe9450f:Fastmail
Date: Mon, 24 Mar 2025 08:41:20 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Xuneng Zhou <xunengzhou@gmail.com>
Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>,
	Andres Freund <andres@anarazel.de>,
	pgsql-hackers@lists.postgresql.org
Subject: Re: Fwd: [BUG]: the walsender does not update its IO statistics
 until it exits
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On Wed, Mar 19, 2025 at 04:00:49PM +0800, Xuneng Zhou wrote:
> Hi,
> Moving the other two provides a more complete view of the settings. For
> newcomers(like me) to the codebase, seeing all three related values in one
> place helps avoid a narrow view of the settings.
>=20
> But I am not sure that I understand the cons of this well.

While I don't disagree with the use of a hardcoded interval of time to
control timing the flush of the WAL sender stats, do we really need to
rely on the timing defined by pgstat.c?  Wouldn't it be simpler to
assign one in walsender.c and pick up a different, perhaps higher,
value?

At the end the timestamp calculations are free because we can rely on
the existing call of GetCurrentTimestamp() for the physical WAL
senders to get an idea of the current time.  For the logical WAL
senders, perhaps we'd better do the reports in WalSndWaitForWal(),
actually.  There is also a call to GetCurrentTimestamp() that we can
rely on in this path.
--
Michael

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