Re: BUG #17974: Walsenders memory usage suddenly spike to 80G+ causing OOM and server reboot

Hi Michael, see below

On Wed., Jun. 14, 2023, 21:02 Michael Paquier, <michael(at)paquier(dot)xyz> wrote:

> On Wed, Jun 14, 2023 at 08:04:53PM -0400, Michael Guissine wrote:
> > On Wed, Jun 14, 2023 at 6:15 PM Andres Freund <andres(at)anarazel(dot)de>
> wrote:
> >>>> Any known issues in pg 14.8 that would trigger this behaviour?
> >>>
> >>> Yes, there are known issues with memory handling in logical
> >>> replication setups. See for example this thread:
> >>>
> >>>
> https://www.postgresql.org/message-id/CAMnUB3oYugXCBLSkih+qNsWQPciEwos6g_AMbnz_peNoxfHwyw@mail.gmail.com
> >>
> >> Why would 14.8 have made that problem worse?
>
> Hmm? I don't necessarily imply that 14.8 made it worse, but that
> there are known issues in this area as the other thread mention (which
> is mainly about v15, actually, where the situation could be a bit
> better).
>
> > This is an assumption obviously, based on the fact that we have been
> > running this database for several years already and haven't seen similar
> > memory issues until the recent upgrade to 14.8.
>
> Was that all the time with 14 as base? What are the minor versions
> you used in the past? Perhaps there is a correlation here that could
> help a bit. There have been a few things in this area lately, like
> 9f2cc1a, 4fbe609, 68dcce2, fd270b7 or 8b9cbd4 (this one made the
> decoding cheaper), so it could be possible that a defect has been
> introduced. Being able to know the contexts where the memory is
> piling up would help a lot, for sure.
>

We started with v 9 or 10 originally I think but the recent upgrade was
from v14.6 to v14.8

--
> Michael
>