On Wed, 18 Jan 2023 at 10:10, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> Alex,
> Do we see this problem with small tuples as well? I see from your
> earlier email that tuple size is ~800 bytes in the production
> environment. It is possible that after commit 1b0d9aa4 such kind of
> problems are not there with small tuple sizes but that commit happened
> in PG15 whereas your production environment might be on a prior
> release.
>
Hi Amit,
Our prod environment is also on 15.1, which is where we first saw the
issue, so I'm afraid the issue still seems to be present here.
Looping back on the earlier discussion, we applied the malloc patch from
[1] ([2]) to a prod server, which also fixes the issue there. Attached is
a graph of the last 48 hours of memory usage, the ~200GB spikes are
instances of the LR walsender memory issue.
After patch is applied (blue mark), baseline memory drops and we no longer
see the spikes. Per-process memory stats corroborate that the LR walsender
memory is now never more than a few MB RSS per process.
Thanks,
- Alex.
[1]
https://www.postgresql.org/message-id/CAMnUB3pwknqoe5s-bGuRD8nX1bWkZRbFF%3DjWNLTWbm_etFigkA%40mail.gmail.com
[2]
https://gist.github.com/alex-richman-onesignal/4ad147b37eaab99f41a150b51899a564
