From: Martin Langhoff Date: Thu, 21 Nov 2013 15:35:39 GMT Subject: Re: Can a git push over ssh trigger a gc/repack? Diagnosing pack explosion Message-ID: In-Reply-To: On Thu, Nov 21, 2013 at 10:21 AM, Martin Langhoff wrote: > Do client pushes over git+ssh ever trigger a repack on the server? man git-config [snip] receive.autogc By default, git-receive-pack will run "git-gc --auto" after receiving data from git-push and updating refs. You can stop it by setting this variable to false. Oooooops! Ok, couple problems here: - if it's receiving from many pushers, it races with itself; needs some lock or back-off mechanism - alternatively, an splay mechanism. We have a "hard" threshold... given many "pushers" acting in parallel, they'll all hit the threshold at the same time. There is no need for this, we could randomize the threshold by 20%; that would radically reduce the racy-ness - auto repack in this scenario has a reasonable likelihood if being visited by the OOM killer -- therefore it needs to fail more gracefully, for example with tmpfile cleanup. Perhaps by having the tmpfiles places in a tmpdir named with the pid of the child would make this easier... Naturally, I'll move quickly to disable this evil-spawn-automagic setting and setup a cronjob. But I think it is possible to have defaults that work more reliably and with lower risk of explosion. thoughts? m -- martin.langhoff@gmail.com - ask interesting questions - don't get distracted with shiny stuff - working code first ~ http://docs.moodle.org/en/User:Martin_Langhoff