Your switches maybe have limits of frames per second. Your journals may be limited by iops. Can you fully describe the system?
On Jan 20, 2017 12:25 AM, "许雪寒" <xuxue...@360.cn> wrote: > The network is only about 10% full, and we tested the performance with > different number of clients, and it turned out that no matter how we > increase the number of clients, the result is the same. > > -----邮件原件----- > 发件人: John Spray [mailto:jsp...@redhat.com] > 发送时间: 2017年1月19日 16:11 > 收件人: 许雪寒 > 抄送: ceph-users@lists.ceph.com > 主题: Re: [ceph-users] Does this indicate a "CPU bottleneck"? > > On Thu, Jan 19, 2017 at 8:51 AM, 许雪寒 <xuxue...@360.cn> wrote: > > Hi, everyone. > > > > > > > > Recently, we did some stress test on ceph using three machines. We > > tested the IOPS of the whole small cluster when there are 1~8 OSDs per > > machines separately and the result is as follows: > > > > > > > > OSD num per machine fio iops > > > > 1 > > 10k > > > > 2 > > 16.5k > > > > 3 > > 22k > > > > 4 > > 23.5k > > > > 5 > > 26k > > > > 6 > > 27k > > > > 7 > > 27k > > > > 8 > > 28k > > > > > > > > As shown above, it seems that there is some kind of bottleneck when > > there are more than 4 OSDs per machine. Meanwhile, we observed that > > the CPU %idle during the test, shown below, has also some kind of > > correlation with the number of OSDs per machine. > > > > > > > > OSD num per machine CPU idle > > > > 1 > > 74% > > > > 2 > > 52% > > > > 3 > > 30% > > > > 4 > > 25% > > > > 5 > > 24% > > > > 6 > > 17% > > > > 7 > > 14% > > > > 8 > > 11% > > > > > > > > It seems that with the number of OSDs per machine increasing, the CPU > > idle time is reducing and the reduce rate Is also decreasing, can we > > come to the conclusion that CPU is the performance bottleneck in this > test? > > Impossible to say without looking at what else was bottlenecked, such as > the network or the client. > > John > > > > > > > Thank youJ > > > > > > _______________________________________________ > > ceph-users mailing list > > ceph-users@lists.ceph.com > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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