On Mon, Aug 5, 2019 at 12:21 AM Janek Bevendorff <janek.bevendo...@uni-weimar.de> wrote: > > Hi, > > > You can also try increasing the aggressiveness of the MDS recall but > > I'm surprised it's still a problem with the settings I gave you: > > > > ceph config set mds mds_recall_max_caps 15000 > > ceph config set mds mds_recall_max_decay_rate 0.75 > > I finally had the chance to try the more aggressive recall settings, but > they did not change anything. As soon as the client starts copying files > again, the numbers go up an I get a health message that the client is > failing to respond to cache pressure. > > After this week of idle time, the dns/inos numbers (what does dns stand > for anyway?) settled at around 8000k. That's basically that "idle" > number that it goes back to when the client stops copying files. Though, > for some weird reason, this number gets (quite) a bit higher every time > (last time it was around 960k). Of course, I wouldn't expect it to go > back all the way to zero, because that would mean dropping the entire > cache for no reason, but it's still quite high and the same after > restarting the MDS and all clients, which doesn't make a lot of sense to > me. After resuming the copy job, the number went up to 20M in just the > time it takes to write this email. There must be a bug somewhere. > > > Can you share two captures of `ceph daemon mds.X perf dump` about 1 > > second apart. > > I attached the requested perf dumps.
Thanks that helps. Looks like the problem is that the MDS is not automatically trimming its cache fast enough. Please try bumping mds_cache_trim_threshold: bin/ceph config set mds mds_cache_trim_threshold 512K Increase it further if it's not aggressive enough. Please let us know if that helps. It shouldn't be necessary to do this so I'll make a tracker ticket once we confirm that's the issue. -- Patrick Donnelly, Ph.D. He / Him / His Senior Software Engineer Red Hat Sunnyvale, CA GPG: 19F28A586F808C2402351B93C3301A3E258DD79D _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
