Infrastructure » sepia

It turns out that each git fetch looks like it buries a CPU in usermode (snarf a bunch, alloc/alloc/alloc, write a bunch; probably consistency checking and compression), and we've recently doubled the number of kraken jobs, by duplicating them onto ovh at the exact same time of day. And it was a 6-cpu host, often 100% busy. So we've doubled the number of CPUs (virtual, of course) and we'll see if that helps out.

We could also think about getting smarter about the 'git clone' that all the workunit tests do, since they're all 1) now cloning the entire Ceph repo, and 2) doing it to multiple client hosts. I'm not certain of the easiest way there, but that's a lot of duplicate work that loads the server.

Greg Farnum suggested maybe a shallow clone might help, and indeed a --depth 1 clone goes MUCH faster than a full (7.6s vs 3m41s, ~5000 objects vs ~500000), so that's a good thing to pursue, I think.

Proposing https://github.com/ceph/ceph/pull/14214

https://github.com/ceph/ceph/pull/14214 is merged. It probably ought to be backported. Leaving this bug open to see if it makes the difference.