On Fri, Aug 2, 2019 at 6:57 PM Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote: > > On Fri, Jul 26, 2019 at 1:02 PM Peter Sabaini <peter@xxxxxxxxxx> wrote: >> >> On 26.07.19 15:03, Stefan Kooman wrote: >> > Quoting Peter Sabaini (peter@xxxxxxxxxx): >> >> What kind of commit/apply latency increases have you seen when adding a >> >> large numbers of OSDs? I'm nervous how sensitive workloads might react >> >> here, esp. with spinners. >> > >> > You mean when there is backfilling going on? Instead of doing "a big >> >> Yes exactly. I usually tune down max rebalance and max recovery active >> knobs to lessen impact but still I found the additional write load can >> substantially increase i/o latencies. Not all workloads like this. > > > We have been using: > > osd op queue = wpq > osd op queue cut off = high > > It virtually eliminates the impact of backfills on our clusters. Our backfill and recovery times have increased when the cluster has lots of client I/O, but the clients haven't noticed that huge backfills have been going on. > > ---------------- > Robert LeBlanc > PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com Would this be superior to setting: osd_recovery_sleep = 0.5 (or some high value) -- Alex Gorbachev Intelligent Systems Services Inc. _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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