On 12/27/2013 12:19 PM, German Anders wrote:
Hi Cephers,
I've run a rados bench to measure the throughput of the cluster,
and found that the performance is really poor:
The setup is the following:
OS: Ubuntu 12.10 Server 64 bits
ceph-node01(mon) 10.77.0.101 ProLiant BL460c G7 32GB 8 x 2 Ghz
10.1.1.151 D2200sb Storage Blade
(Firmware: 2.30)
ceph-node02(mon) 10.77.0.102 ProLiant BL460c G7 64GB 8 x 2 Ghz
10.1.1.152 D2200sb Storage Blade
(Firmware: 2.30)
ceph-node03(mon) 10.77.0.103 ProLiant BL460c G6 32GB 8 x 2 Ghz
10.1.1.153 D2200sb Storage Blade
(Firmware: 2.30)
ceph-node04 10.77.0.104 ProLiant BL460c G7 32GB 8 x
2 Ghz
10.1.1.154 D2200sb Storage Blade
(Firmware: 2.30)
ceph-node05(deploy) 10.77.0.105 ProLiant BL460c G6 32GB 8 x
2 Ghz
10.1.1.155 D2200sb Storage
Blade (Firmware: 2.30)
If your servers have controllers with writeback cache, please make sure
it is enabled as that will likely help.
ceph-node01:
/dev/sda 73G (OSD)
/dev/sdb 73G (OSD)
/dev/sdc 73G (OSD)
/dev/sdd 73G (OSD)
/dev/sde 73G (OSD)
/dev/sdf 73G (OSD)
/dev/sdg 73G (OSD)
/dev/sdh 73G (OSD)
/dev/sdi 73G (OSD)
/dev/sdj 73G (Journal)
/dev/sdk 500G (OSD)
/dev/sdl 500G (OSD)
/dev/sdn 146G (Journal)
ceph-node02:
/dev/sda 73G (OSD)
/dev/sdb 73G (OSD)
/dev/sdc 73G (OSD)
/dev/sdd 73G (OSD)
/dev/sde 73G (OSD)
/dev/sdf 73G (OSD)
/dev/sdg 73G (OSD)
/dev/sdh 73G (OSD)
/dev/sdi 73G (OSD)
/dev/sdj 73G (Journal)
/dev/sdk 500G (OSD)
/dev/sdl 500G (OSD)
/dev/sdn 146G (Journal)
ceph-node03:
/dev/sda 73G (OSD)
/dev/sdb 73G (OSD)
/dev/sdc 73G (OSD)
/dev/sdd 73G (OSD)
/dev/sde 73G (OSD)
/dev/sdf 73G (OSD)
/dev/sdg 73G (OSD)
/dev/sdh 73G (OSD)
/dev/sdi 73G (OSD)
/dev/sdj 73G (Journal)
/dev/sdk 500G (OSD)
/dev/sdl 500G (OSD)
/dev/sdn 73G (Journal)
ceph-node04:
/dev/sda 73G (OSD)
/dev/sdb 73G (OSD)
/dev/sdc 73G (OSD)
/dev/sdd 73G (OSD)
/dev/sde 73G (OSD)
/dev/sdf 73G (OSD)
/dev/sdg 73G (OSD)
/dev/sdh 73G (OSD)
/dev/sdi 73G (OSD)
/dev/sdj 73G (Journal)
/dev/sdk 500G (OSD)
/dev/sdl 500G (OSD)
/dev/sdn 146G (Journal)
ceph-node05:
/dev/sda 73G (OSD)
/dev/sdb 73G (OSD)
/dev/sdc 73G (OSD)
/dev/sdd 73G (OSD)
/dev/sde 73G (OSD)
/dev/sdf 73G (OSD)
/dev/sdg 73G (OSD)
/dev/sdh 73G (OSD)
/dev/sdi 73G (OSD)
/dev/sdj 73G (Journal)
/dev/sdk 500G (OSD)
/dev/sdl 500G (OSD)
/dev/sdn 73G (Journal)
Am I correct in assuming that you've put all of your journals for every
disk in each node on two spinning disks? This is going to be quite
slow, because Ceph does a full write of the data the journal for every
real write. The general solution is to either use SSDs for journals
(preferably multiple fast SSDs with high write endurance and only 3-6
OSD journals each), or put the journals on a partition on the data disk.
And the OSD tree is:
root@ceph-node03:/home/ceph# ceph osd tree
# id weight type name up/down reweight
-1 7.27 root default
-2 1.15 host ceph-node01
12 0.06999 osd.12 up 1
13 0.06999 osd.13 up 1
14 0.06999 osd.14 up 1
15 0.06999 osd.15 up 1
16 0.06999 osd.16 up 1
17 0.06999 osd.17 up 1
18 0.06999 osd.18 up 1
19 0.06999 osd.19 up 1
20 0.06999 osd.20 up 1
21 0.45 osd.21 up 1
22 0.06999 osd.22 up 1
-3 1.53 host ceph-node02
23 0.06999 osd.23 up 1
24 0.06999 osd.24 up 1
25 0.06999 osd.25 up 1
26 0.06999 osd.26 up 1
27 0.06999 osd.27 up 1
28 0.06999 osd.28 up 1
29 0.06999 osd.29 up 1
30 0.06999 osd.30 up 1
31 0.06999 osd.31 up 1
32 0.45 osd.32 up 1
33 0.45 osd.33 up 1
-4 1.53 host ceph-node03
34 0.06999 osd.34 up 1
35 0.06999 osd.35 up 1
36 0.06999 osd.36 up 1
37 0.06999 osd.37 up 1
38 0.06999 osd.38 up 1
39 0.06999 osd.39 up 1
40 0.06999 osd.40 up 1
41 0.06999 osd.41 up 1
42 0.06999 osd.42 up 1
43 0.45 osd.43 up 1
44 0.45 osd.44 up 1
-5 1.53 host ceph-node04
0 0.06999 osd.0 up 1
1 0.06999 osd.1 up 1
2 0.06999 osd.2 up 1
3 0.06999 osd.3 up 1
4 0.06999 osd.4 up 1
5 0.06999 osd.5 up 1
6 0.06999 osd.6 up 1
7 0.06999 osd.7 up 1
8 0.06999 osd.8 up 1
9 0.45 osd.9 up 1
10 0.45 osd.10 up 1
-6 1.53 host ceph-node05
11 0.06999 osd.11 up 1
45 0.06999 osd.45 up 1
46 0.06999 osd.46 up 1
47 0.06999 osd.47 up 1
48 0.06999 osd.48 up 1
49 0.06999 osd.49 up 1
50 0.06999 osd.50 up 1
51 0.06999 osd.51 up 1
52 0.06999 osd.52 up 1
53 0.45 osd.53 up 1
54 0.45 osd.54 up 1
Based on this, it appears your 500GB drives are weighted much higher
than the 73GB drives. This will help even data distribution out, but
unfortunately will cause the system to be slower if all of the OSDs are
in the same pool. What this does is cause the 500GB drives to get a
higher proportion of the writes than the other drives, but those drives
are almost certainly no faster than the other ones. Because there is a
limited number of outstanding IOs you can have (due to memory
constraints), eventually all outstanding IOs will be waiting on the
500GB disks while the 73GB disks mostly sit around waiting for work.
What I'd suggest doing is putting all of your 73 disks in the same pool
and your 500GB disks in another pool. I suspect that if you do that and
put your journals on the first partition of each disk, you'll see some
improvement in your benchmark results.
And the result:
root@ceph-node03:/home/ceph# rados bench -p ceph-cloud 20 write -t 10
Maintaining 10 concurrent writes of 4194304 bytes for up to 20 seconds
or 0 objects
Object prefix: benchmark_data_ceph-node03_29727
sec Cur ops started finished avg MB/s cur MB/s last lat avg lat
0 0 0 0 0 0 - 0
1 10 30 20 79.9465 80 0.159295 0.378849
2 10 52 42 83.9604 88 0.719616 0.430293
3 10 74 64 85.2991 88 0.487685 0.412956
4 10 97 87 86.9676 92 0.351122 0.418814
5 10 123 113 90.3679 104 0.317011 0.418876
6 10 147 137 91.3012 96 0.562112 0.418178
7 10 172 162 92.5398 100 0.691045 0.413416
8 10 197 187 93.469 100 0.459424 0.415459
9 10 222 212 94.1915 100 0.798889 0.416093
10 10 248 238 95.1697 104 0.440002 0.415609
11 10 267 257 93.4252 76 0.48959 0.41531
12 10 289 279 92.9707 88 0.524622 0.420145
13 10 313 303 93.2016 96 1.02104 0.423955
14 10 336 326 93.1136 92 0.477328 0.420684
15 10 359 349 93.037 92 0.591118 0.418589
16 10 383 373 93.2204 96 0.600392 0.421916
17 10 407 397 93.3812 96 0.240166 0.419829
18 10 431 421 93.526 96 0.746706 0.420971
19 10 457 447 94.0757 104 0.237565 0.419025
2013-12-27 13:13:21.817874min lat: 0.101352 max lat: 1.81426 avg lat:
0.418242
sec Cur ops started finished avg MB/s cur MB/s last lat avg lat
20 10 480 470 93.9709 92 0.489254 0.418242
Total time run: 20.258064
Total writes made: 481
Write size: 4194304
Bandwidth (MB/sec): 94.975
Stddev Bandwidth: 21.7799
Max bandwidth (MB/sec): 104
Min bandwidth (MB/sec): 0
Average Latency: 0.420573
Stddev Latency: 0.226378
Max latency: 1.81426
Min latency: 0.101352
root@ceph-node03:/home/ceph#
Thanks in advance,
Best regards,
*German Anders*
_______________________________________________
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
