Re: Race between KeepFileRestoredFromArchive() and restartpoint

At Wed, 3 Aug 2022 23:24:56 -0700, Noah Misch <noah(at)leadboat(dot)com> wrote in
> > > I think in this case a HINT might be sufficient to at least keep people from
> > > wasting time tracking down a problem that has already been fixed.
>
> Here's a patch to add that HINT. I figure it's better to do this before next
> week's minor releases. In the absence of objections, I'll push this around
> 2022-08-05 14:00 UTC.

+1

> > > However, there is another issue [1] that might argue for a back patch if
> > > this patch (as I believe) would fix the issue.
> >
> > > [1] https://www.postgresql.org/message-id/CAHJZqBDxWfcd53jm0bFttuqpK3jV2YKWx%3D4W7KxNB4zzt%2B%2BqFg%40mail.gmail.com
> >
> > That makes sense. Each iteration of the restartpoint recycle loop has a 1/N
> > chance of failing. Recovery adds >N files between restartpoints. Hence, the
> > WAL directory grows without bound. Is that roughly the theory in mind?
>
> On further reflection, I don't expect it to happen that way. Each failure
> message is LOG-level, so the remaining recycles still happen. (The race
> condition can yield an ERROR under PreallocXlogFiles(), but recycling is
> already done at that point.)

I agree to this.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center