Fwd: [BUG]: the walsender does not update its IO statistics until it exits

Sorry, forgot to cc this one too.

---------- Forwarded message ---------
发件人： Xuneng Zhou <xunengzhou(at)gmail(dot)com>
Date: 2025年3月13日周四 19:29
Subject: Re: [BUG]: the walsender does not update its IO statistics until
it exits
To: Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com>

Hi,
Given that PGSTAT_MIN_INTERVAL is the go-to setting for stats flushes
* Unless called with 'force', pending stats updates are flushed happen once
* per PGSTAT_MIN_INTERVAL (1000ms). When not forced, stats flushes do not
* block on lock acquisition, except if stats updates have been pending for
* longer than PGSTAT_MAX_INTERVAL (60000ms).
*
* Whenever pending stats updates remain at the end of pgstat_report_stat()
a
* suggested idle timeout is returned. Currently this is always
* PGSTAT_IDLE_INTERVAL (10000ms). Callers can use the returned time to set
up
* a timeout after which to call pgstat_report_stat(true), but are not
* required to do so.

I am curious about the reason for this:

> 1. maybe relying on PGSTAT_IDLE_INTERVAL would make more sense? In both
> case
> PGSTAT_MIN_INTERVAL or PGSTAT_MIN_INTERVAL, I'm not sure there is a need to
> update the related doc.
>
>
PGSTAT_IDLE_INTERVAL seems to reduce the frequency even more.

>
> With the attached in place, the number of times the stats are being flushed
> reduce drastically but still seems enough to get an accurate idea of the
> walsender
> IO activity. Thoughts?
>
>
>