From: Taylor Blau <me@ttaylorr.com>
To: Gregory Szorc <gregory.szorc@gmail.com>
Cc: git@vger.kernel.org, stolee@gmail.com
Subject: Re: Race condition between repack and loose-objects maintenance task
Date: Wed, 29 Jun 2022 13:21:14 -0400 [thread overview]
Message-ID: <YryKCl5J1Em89d3e@nand.local> (raw)
In-Reply-To: <CAKQoGakSFaNm10ZeTKc8XtTcD0JW19CZP1OwA4j7W__iBQaJfg@mail.gmail.com>
On Wed, Jun 29, 2022 at 10:16:38AM -0700, Gregory Szorc wrote:
> > In either case, my recommendation would be to keep those unreachable
> > objects which haven't yet aged out of the repository around for longer,
> > which will decrease the likelihood of seeing the race.
>
> We had to lower gc.pruneExpire from its default of 1 hour because
> otherwise this would result in the creation of thousands of loose
> objects. This is normally acceptable. However, on NFS, the churn from
> lots of file creation and deletion resulted in acceptable performance
> degradation. We had to lower gc.pruneExpire to minimize the damage.
Makes sense. Having a shorter gc.pruneExpire makes the race much more
likely to occur in practice, so I'm glad that we have a plausible
confirmation that that's what's going on in your repository.
> > See Documentation/technical/cruft-packs.txt for more information about
> > cruft packs.
>
> Yes, I saw this new feature in the Git release this week and am hoping
> to roll it out to better mitigate this general problem! With cruft
> packs, I anticipate being able to restore a longer gc.pruneExpire
> value as they should mitigate the NFS performance badness we're
> working around. Thank you for confirming it should help with the
> problem.
That should definitely help. Let me know if you have any questions, and
thanks for trying it out!
Thanks,
Taylor
next prev parent reply other threads:[~2022-06-29 17:21 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-29 16:55 Race condition between repack and loose-objects maintenance task Gregory Szorc
2022-06-29 17:03 ` Taylor Blau
2022-06-29 17:10 ` Taylor Blau
2022-06-29 17:16 ` Gregory Szorc
2022-06-29 17:21 ` Taylor Blau [this message]
2022-06-30 0:44 ` Gregory Szorc
2022-06-30 3:19 ` Taylor Blau
2022-06-30 3:23 ` Taylor Blau
2022-06-30 20:12 ` Junio C Hamano
2022-07-05 18:43 ` Gregory Szorc
2022-07-06 8:50 ` Ævar Arnfjörð Bjarmason
2022-07-20 1:40 ` Gregory Szorc
2022-07-20 9:52 ` Ævar Arnfjörð Bjarmason
2022-07-26 16:22 ` Gregory Szorc
2022-07-26 18:11 ` Ævar Arnfjörð Bjarmason
2022-07-20 1:41 ` Gregory Szorc
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