On Thu, Jun 4, 2015 at 3:57 AM, Межов Игорь Александрович <me...@yuterra.ru> wrote: > Hi! > >> My deployments have seen many different versions of ceph. Pre 0.80.7, I've >> seen those numbers being pretty high. After upgrading to 0.80.7, all of a >> sudden, commit latency of all OSDs drop to 0-1ms, and apply latency >> remains >> pretty low most of the time. > > We use now Ceph 0.80.7-1~bpo70+1 on Debian Wheezy + 3.16.4 kernel, > backported > from Jessie. And I can't see commit latency in perf dumps, only > "commitcycle_latency". > Is it the right perf parameters you discuss here? Our values are too high - > on the nodes > with RAID0-per-disk it is between 20 and 120 ms, on the nodes with straight > HBA > passtrough is worser - 200-600ms.
This particular value is basically how long the syncfs call takes to complete. It's not the direct time for a particular operation to commit. > > But apply latency is between 3 and 19ms with avg=7.2 ms, journal latencies > are > also good = 0.49-1.84 ms. Yeah, those seem reasonable. -Greg _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
