On Mon, Mar 19, 2018 at 11:45 PM, Nicolas Huillard <nhuillard@xxxxxxxxxxx> wrote: > Le lundi 19 mars 2018 à 15:30 +0300, Sergey Malinin a écrit : >> Default for mds_log_events_per_segment is 1024, in my set up I ended >> up with 8192. >> I calculated that value like IOPS / log segments * 5 seconds (afaik >> MDS performs journal maintenance once in 5 seconds by default). > > I tried 4096 from the initial 1024, then 8192 at the time of your > answer, then 16384, with not much improvements... > > Then I tried to reduce the number of MDS, from 4 to 1, which definitely > works (sorry if my initial mail didn't make it very clear that I was > using many MDSs, even though it mentioned mds.2). > I now have low rate of metadata write (40-50kBps), and the inter-DC > link load reflects the size and direction of the actual data. > > I'll now try to reduce mds_log_events_per_segment back to its original > value (1024), because performance is not optimal, and stutters a bit > too much. > > Thanks for your advice! > This seems like load balancer bug. Improving load balancer is on the top of our todo list. Regards Yan, Zheng > -- > Nicolas Huillard > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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