Re: Report checkpoint progress in server logs - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Report checkpoint progress in server logs
Date
Msg-id YdYs4G8WlD2Op5tJ@momjian.us
Whole thread Raw
In response to Re: Report checkpoint progress in server logs  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Report checkpoint progress in server logs
List pgsql-hackers
On Wed, Dec 29, 2021 at 10:40:59AM -0500, Tom Lane wrote:
> Magnus Hagander <magnus@hagander.net> writes:
> >> Therefore, reporting the checkpoint progress in the server logs, much
> >> like [1], seems to be the best way IMO.
> 
> > I find progress reporting in the logfile to generally be a terrible
> > way of doing things, and the fact that we do it for the startup
> > process is/should be only because we have no other choice, not because
> > it's the right choice.
> 
> I'm already pretty seriously unhappy about the log-spamming effects of
> 64da07c41 (default to log_checkpoints=on), and am willing to lay a side
> bet that that gets reverted after we have some field experience with it.
> This proposal seems far worse from that standpoint.  Keep in mind that
> our out-of-the-box logging configuration still doesn't have any log
> rotation ability, which means that the noisier the server is in normal
> operation, the sooner you fill your disk.

I think we are looking at three potential observable behaviors people
might care about:

*  the current activity/progress of checkpoints
*  the historical reporting of checkpoint completion, mixed in with other
   log messages for later analysis
*  the aggregate behavior of checkpoint operation

I think it is clear that checkpoint progress activity isn't useful for
the server logs because that information has little historical value,
but does fit for a progress view.  As Tom already expressed, we will
have to wait to see if non-progress checkpoint information in the logs
has sufficient historical value.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.




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