Greq, for example for our cluster ~1000 osd: size osdmap.1357881__0_F7FE779D__none = 363KB (crush_version 9860, modified 2018-12-12 04:00:17.661731) size osdmap.1357882__0_F7FE772D__none = 363KB size osdmap.1357883__0_F7FE74FD__none = 363KB (crush_version 9861, modified 2018-12-12 04:00:27.385702) size inc_osdmap.1357882__0_B783A4EA__none = 1.2MB
difference between epoch 1357881 and 1357883: crush weight one osd was increased by 0.01 so we get 5 new pg_temp in osdmap.1357883 but size inc_osdmap so huge чт, 6 дек. 2018 г. в 06:20, Gregory Farnum <gfar...@redhat.com>: > > On Wed, Dec 5, 2018 at 3:32 PM Sergey Dolgov <palz...@gmail.com> wrote: >> >> Hi guys >> >> I faced strange behavior of crushmap change. When I change crush >> weight osd I sometimes get increment osdmap(1.2MB) which size is >> significantly bigger than size of osdmap(0.4MB) > > > This is probably because when CRUSH changes, the new primary OSDs for a PG > will tend to set a "pg temp" value (in the OSDMap) that temporarily reassigns > it to the old acting set, so the data can be accessed while the new OSDs get > backfilled. Depending on the size of your cluster, the number of PGs on it, > and the size of the CRUSH change, this can easily be larger than the rest of > the map because it is data with size linear in the number of PGs affected, > instead of being more normally proportional to the number of OSDs. > -Greg > >> >> I use luminois 12.2.8. Cluster was installed a long ago, I suppose >> that initially it was firefly >> How can I view content of increment osdmap or can you give me opinion >> on this problem. I think that spikes of traffic tight after change of >> crushmap relates to this crushmap behavior >> _______________________________________________ >> ceph-users mailing list >> ceph-users@lists.ceph.com >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Best regards, Sergey Dolgov _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
