If I create a new pool it is generally fast for a short amount of time. Not as fast as if I had a blank cluster, but close to. Bryn > On 8 Jul 2015, at 13:55, Gregory Farnum <greg@xxxxxxxxxxx> wrote: > > I think you're probably running into the internal PG/collection > splitting here; try searching for those terms and seeing what your OSD > folder structures look like. You could test by creating a new pool and > seeing if it's faster or slower than the one you've already filled up. > -Greg > > On Wed, Jul 8, 2015 at 1:25 PM, MATHIAS, Bryn (Bryn) > <bryn.mathias@xxxxxxxxxxxxxxxxxx> wrote: >> Hi All, >> >> >> I’m perf testing a cluster again, >> This time I have re-built the cluster and am filling it for testing. >> >> on a 10 min run I get the following results from 5 load generators, each writing though 7 iocontexts, with a queue depth of 50 async writes. >> >> >> Gen1 >> Percentile 100 = 0.729775905609 >> Max latencies = 0.729775905609, Min = 0.0320818424225, mean = 0.0750389684542 >> Total objects writen = 113088 in time 604.259738207s gives 187.151307376/s (748.605229503 MB/s) >> >> Gen2 >> Percentile 100 = 0.735981941223 >> Max latencies = 0.735981941223, Min = 0.0340068340302, mean = 0.0745198070711 >> Total objects writen = 113822 in time 604.437897921s gives 188.310495407/s (753.241981627 MB/s) >> >> Gen3 >> Percentile 100 = 0.828994989395 >> Max latencies = 0.828994989395, Min = 0.0349340438843, mean = 0.0745455575197 >> Total objects writen = 113670 in time 604.352181911s gives 188.085694736/s (752.342778944 MB/s) >> >> Gen4 >> Percentile 100 = 1.06834602356 >> Max latencies = 1.06834602356, Min = 0.0333499908447, mean = 0.0752239764659 >> Total objects writen = 112744 in time 604.408732891s gives 186.536020849/s (746.144083397 MB/s) >> >> Gen5 >> Percentile 100 = 0.609658002853 >> Max latencies = 0.609658002853, Min = 0.032968044281, mean = 0.0744482759499 >> Total objects writen = 113918 in time 604.671534061s gives 188.396498897/s (753.585995589 MB/s) >> >> example ceph -w output: >> 2015-07-07 15:50:16.507084 mon.0 [INF] pgmap v1077: 2880 pgs: 2880 active+clean; 1996 GB data, 2515 GB used, 346 TB / 348 TB avail; 2185 MB/s wr, 572 op/s >> >> >> However when the cluster gets over 20% full I see the following results, this gets worse as the cluster fills up: >> >> Gen1 >> Percentile 100 = 6.71176099777 >> Max latencies = 6.71176099777, Min = 0.0358741283417, mean = 0.161760483485 >> Total objects writen = 52196 in time 604.488474131s gives 86.347386648/s (345.389546592 MB/s) >> >> Gen2 >> Max latencies = 4.09169006348, Min = 0.0357890129089, mean = 0.163243938477 >> Total objects writen = 51702 in time 604.036739111s gives 85.5941313704/s (342.376525482 MB/s) >> >> Gen3 >> Percentile 100 = 7.32526683807 >> Max latencies = 7.32526683807, Min = 0.0366668701172, mean = 0.163992217926 >> Total objects writen = 51476 in time 604.684302092s gives 85.1287189397/s (340.514875759 MB/s) >> >> Gen4 >> Percentile 100 = 7.56094503403 >> Max latencies = 7.56094503403, Min = 0.0355761051178, mean = 0.162109421231 >> Total objects writen = 52092 in time 604.769910812s gives 86.1352376642/s (344.540950657 MB/s) >> >> >> Gen5 >> Percentile 100 = 6.99595499039 >> Max latencies = 6.99595499039, Min = 0.0364680290222, mean = 0.163651215426 >> Total objects writen = 51566 in time 604.061977148s gives 85.3654127404/s (341.461650961 MB/s) >> >> >> >> >> >> >> Cluster details: >> 5*HPDL380’s with 13*6Tb OSD’s >> 128Gb Ram >> 2*intel 2620v3 >> 10 Gbit Ceph public network >> 10 Gbit Ceph private network >> >> Load generators connected via a 20Gbit bond to the ceph public network. >> >> >> Is this likely to be something happening to the journals? >> >> Or is there something else going on. >> >> I have run FIO and iperf tests and the disk and network performance is very high. >> >> >> Kind Regards, >> Bryn Mathias >> >> >> >> >> >> >> _______________________________________________ >> 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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