On Wed, Nov 4, 2020 at 2:57 PM Tomas Vondra
<tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
> On Wed, Nov 04, 2020 at 02:49:24PM +1300, Thomas Munro wrote:
> >On Wed, Nov 4, 2020 at 2:32 PM Tomas Vondra
> ><tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
> >> After a while (~1h on my machine) the pg_multixact gets over 10GB, which
> >> triggers a more aggressive cleanup (per MultiXactMemberFreezeThreshold).
> >> My guess is that this discards some of the files, but checkpointer is
> >> not aware of that, or something like that. Not sure.
> >
> >Urgh. Thanks. Looks like perhaps the problem is that I have
> >RegisterSyncRequest(&tag, SYNC_FORGET_REQUEST, true) in one codepath
> >that unlinks files, but not another. Looking.
>
> Maybe. I didn't have time to investigate this more deeply, and it takes
> quite a bit of time to reproduce. I can try again with extra logging or
> test some proposed fixes, if you give me a patch.
I think this should be fixed by doing all unlinking through a common
code path. Does this pass your test?