Re: poor performance

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 11/04/2012 07:18 AM, Aleksey Samarin wrote:
Well, i create ceph cluster with 2 osd ( 1 osd per node),  2 mon, 2 mds.
here is what I did:
  ceph osd pool create bench
  ceph osd tell \* bench
  rados -p bench bench 30 write --no-cleanup
output:

  Maintaining 16 concurrent writes of 4194304 bytes for at least 30 seconds.
  Object prefix: benchmark_data_host01_11635
    sec Cur ops   started  finished  avg MB/s  cur MB/s  last lat   avg lat
      0       0         0         0         0         0         -         0
      1      16        16         0         0         0         -         0
      2      16        37        21   41.9911        42  0.139005   1.08941
      3      16        53        37   49.3243        64  0.754114   1.09392
      4      16        75        59   58.9893        88  0.284647  0.914221
      5      16        89        73   58.3896        56  0.072228  0.881008
      6      16        95        79   52.6575        24   1.56959  0.961477
      7      16       111        95   54.2764        64  0.046105   1.08791
      8      16       128       112   55.9906        68  0.035714   1.04594
      9      16       150       134   59.5457        88  0.046298   1.04415
     10      16       166       150   59.9901        64  0.048635  0.986384
     11      16       176       160   58.1723        40  0.727784  0.988408
     12      16       206       190   63.3231       120   0.28869  0.946624
     13      16       225       209   64.2976        76   1.34472  0.919464
     14      16       263       247   70.5605       152  0.070926   0.90046
     15      16       295       279   74.3887       128  0.041517  0.830466
     16      16       315       299   74.7388        80  0.296037  0.841527
     17      16       333       317   74.5772        72  0.286097  0.849558
     18      16       340       324   71.9891        28  0.295084   0.83922
     19      16       343       327   68.8317        12   1.46948  0.845797
2012-11-04 17:14:52.090941min lat: 0.035714 max lat: 2.64841 avg lat: 0.861539
    sec Cur ops   started  finished  avg MB/s  cur MB/s  last lat   avg lat
     20      16       378       362    72.389       140  0.566232  0.861539
     21      16       400       384   73.1313        88  0.038835  0.857785
     22      16       404       388   70.5344        16  0.801216  0.857002
     23      16       413       397   69.0327        36  0.062256   0.86376
     24      16       428       412   68.6543        60  0.042583   0.89389
     25      16       450       434   69.4277        88  0.383877  0.905833
     26      16       472       456   70.1415        88  0.269878  0.898023
     27      16       472       456   67.5437         0         -  0.898023
     28      16       512       496   70.8448        80  0.056798  0.891163
     29      16       530       514   70.8843        72   1.20653  0.898112
     30      16       542       526   70.1212        48  0.744383  0.890733
  Total time run:         30.174151
Total writes made:      543
Write size:             4194304
Bandwidth (MB/sec):     71.982

Stddev Bandwidth:       38.318
Max bandwidth (MB/sec): 152
Min bandwidth (MB/sec): 0
Average Latency:        0.889026
Stddev Latency:         0.677425
Max latency:            2.94467
Min latency:            0.035714


Much better for 1 disk per node! I suspect that lack of syncfs is hurting you, or perhaps some other issue with writes to lots of disks at the same time.



2012/11/4 Aleksey Samarin <nrg3tik@xxxxxxxxx>:
Ok!
Well, I'll take these tests and write about the results.

btw,
disks are the same, as some may be faster than others?

2012/11/4 Gregory Farnum <greg@xxxxxxxxxxx>:
That's only nine — where are the other three? If you have three slow
disks that could definitely cause the troubles you're seeing.

Also, what Mark said about sync versus syncfs.

On Sun, Nov 4, 2012 at 1:26 PM, Aleksey Samarin <nrg3tik@xxxxxxxxx> wrote:
It`s ok!

Output:

2012-11-04 16:19:23.195891 osd.0 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 11.441035 sec at 91650 KB/sec
2012-11-04 16:19:24.981631 osd.1 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 13.225048 sec at 79287 KB/sec
2012-11-04 16:19:25.672896 osd.2 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 13.917157 sec at 75344 KB/sec
2012-11-04 16:19:28.058517 osd.21 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 16.453375 sec at 63730 KB/sec
2012-11-04 16:19:28.715552 osd.22 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 17.108887 sec at 61288 KB/sec
2012-11-04 16:19:23.440054 osd.23 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 11.834639 sec at 88602 KB/sec
2012-11-04 16:19:24.023650 osd.24 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 12.418276 sec at 84438 KB/sec
2012-11-04 16:19:24.617514 osd.25 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 13.011955 sec at 80585 KB/sec
2012-11-04 16:19:25.148613 osd.26 [INF] bench: wrote 1024 MB in blocks
of 4096 KB in 13.541710 sec at 77433 KB/sec

All the best.

2012/11/4 Gregory Farnum <greg@xxxxxxxxxxx>:
[Sorry for the blank email; I missed!]
On Sun, Nov 4, 2012 at 1:04 PM, Aleksey Samarin <nrg3tik@xxxxxxxxx> wrote:
Hi!
This command? ceph tell osd \* bench
Output:  tell target 'osd' not a valid entity name

I guess it's "ceph osd tell \* bench". Try that one. :)

Well, i did pool by command ceph osd pool create bench2 120
This output of rados -p bench2 bench 30 write --no-cleanup

rados -p bench2 bench 30 write --no-cleanup

  Maintaining 16 concurrent writes of 4194304 bytes for at least 30 seconds.
  Object prefix: benchmark_data_host01_5827
    sec Cur ops   started  finished  avg MB/s  cur MB/s  last lat   avg lat
      0       0         0         0         0         0         -         0
      1      16        29        13   51.9885        52  0.489268  0.186749
      2      16        52        36   71.9866        92   1.87226  0.711888
      3      16        57        41    54.657        20  0.089697  0.697821
      4      16        60        44   43.9923        12   1.61868  0.765361
      5      16        60        44   35.1941         0         -  0.765361
      6      16        60        44   29.3285         0         -  0.765361
      7      16        60        44   25.1388         0         -  0.765361
      8      16        61        45   22.4964         1   5.89643  0.879384
      9      16        62        46   20.4412         4    6.0234  0.991211
     10      16        62        46   18.3971         0         -  0.991211
     11      16        63        47   17.0883         2   8.79749    1.1573
     12      16        63        47   15.6643         0         -    1.1573
     13      16        63        47   14.4593         0         -    1.1573
     14      16        63        47   13.4266         0         -    1.1573
     15      16        63        47   12.5315         0         -    1.1573
     16      16        63        47   11.7483         0         -    1.1573
     17      16        63        47   11.0572         0         -    1.1573
     18      16        63        47   10.4429         0         -    1.1573
     19      16        63        47   9.89331         0         -    1.1573
2012-11-04 15:58:15.473733min lat: 0.036475 max lat: 8.79749 avg lat: 1.1573
    sec Cur ops   started  finished  avg MB/s  cur MB/s  last lat   avg lat
     20      16        63        47   9.39865         0         -    1.1573
     21      16        63        47   8.95105         0         -    1.1573
     22      16        63        47   8.54419         0         -    1.1573
     23      16        63        47   8.17271         0         -    1.1573
     24      16        63        47   7.83218         0         -    1.1573
     25      16        63        47    7.5189         0         -    1.1573
     26      16        63        47   7.22972         0         -    1.1573
     27      16        81        65   9.62824       4.5  0.076456    4.9428
     28      16       118       102   14.5693       148  0.427273   4.34095
     29      16       119       103   14.2049         4   1.57897   4.31414
     30      16       132       116   15.4645        52   2.25424   4.01492
     31      16       133       117   15.0946         4  0.974652   3.98893
     32      16       133       117   14.6229         0         -   3.98893
  Total time run:         32.575351
Total writes made:      133
Write size:             4194304
Bandwidth (MB/sec):     16.331

Stddev Bandwidth:       31.8794
Max bandwidth (MB/sec): 148
Min bandwidth (MB/sec): 0
Average Latency:        3.91583
Stddev Latency:         7.42821
Max latency:            25.24
Min latency:            0.036475

Im think problem not in pg. This output of ceph pg dump  >
http://pastebin.com/BqLsyMBC

Well, that did improve it a bit; but yes, I think there's something
else going on. Just wanted to verify. :)


I have still no idea.

All the best. Alex



2012/11/4 Gregory Farnum <greg@xxxxxxxxxxx>:
On Sun, Nov 4, 2012 at 10:58 AM, Aleksey Samarin <nrg3tik@xxxxxxxxx> wrote:
Hi all

Im planning use ceph for cloud storage.
My test setup is 2 servers connected via infiniband 40Gb, 6x2Tb disks per node.
Centos 6.2
Ceph 0.52 from http://ceph.com/rpms/el6/x86_64
This is my config http://pastebin.com/Pzxafnsm
journal on tmpfs
well, im create bench pool and test it:
ceph osd pool create bench
rados -p bench bench 30 write

  Total time run:         43.258228
  Total writes made:      151
  Write size:             4194304
  Bandwidth (MB/sec):     13.963
  Stddev Bandwidth:       26.307
  Max bandwidth (MB/sec): 128
  Min bandwidth (MB/sec): 0
  Average Latency:        4.48605
  Stddev Latency:         8.17709
  Max latency:            29.7957
  Min latency:            0.039435

when i do rados -p bench bench 30 seq
  Total time run:        20.626935
  Total reads made:     275
  Read size:            4194304
  Bandwidth (MB/sec):    53.328
  Average Latency:       1.19754
  Max latency:           7.0215
  Min latency:           0.011647

I tested the single drive via dd if=/dev/zero of=/mnt/hdd2/testfile
bs=1024k count=20000
result:  158 MB/sec

Anyone can tell me why such a weak performance? Maybe I missed something?

Can you run "ceph tell osd \* bench" and report the results? (It'll go
to the "central log" which you can keep an eye on if you run "ceph -w"
in another terminal.)
I think you also didn't create your bench pool correctly; it probably
only has 8 PGs which is not going to perform very well with your disk
count. Try "ceph pool create bench2 120" and run the benchmark against
that pool. The extra number at the end tells it to create 120
placement groups.
-Greg
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [CEPH Users]     [Ceph Large]     [Information on CEPH]     [Linux BTRFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux