[Gluster-users] Slow read performance

Thomas Wakefield twake at cola.iges.org
Thu Mar 7 20:08:13 UTC 2013


Everything is built as ext4, no options other than lazy_itable_init=1 when I built the filesystems.  

Server mount example:
LABEL=disk2a 	/storage/disk2a 	ext4	defaults 0 0

Client mount:
fs-disk2:/shared /shared glusterfs defaults 0 0

Remember, the slow reads are only from gluster clients, the disks are really fast when I am local on the server testing the disks.


-Tom




On Mar 7, 2013, at 1:09 PM, Bryan Whitehead <driver at megahappy.net> wrote:

> Was just thinking, what is your mount options for your bricks (using inode64?)? Also, you are using xfs... right?
> 
> When you created the filesystems did you allocate more inode space? -i size=512 ?
> 
> 
> On Thu, Mar 7, 2013 at 5:49 AM, Thomas Wakefield <twake at cola.iges.org> wrote:
> Still looking for help.
> 
> 
> On Mar 4, 2013, at 7:43 AM, Thomas Wakefield <twake at iges.org> wrote:
> 
>> Also, I tested an NFS mount over the same 10GB link, and was able to pull almost 200MB/s.  But Gluster is still much slower.  Also I tested running it for a longer test, 105GB of data, and still showed that writing is MUCH faster.  Which makes no sense when the disks can read 2x as fast as they can write.
>> 
>> Any other thoughts?
>> 
>> [root at cpu_crew1 ~]# dd if=/dev/zero of=/shared/working/benchmark/test.cpucrew1 bs=512k count=200000 ; dd if=/shared/working/benchmark/test.cpucrew1 of=/dev/null bs=512k
>> 200000+0 records in
>> 200000+0 records out
>> 104857600000 bytes (105 GB) copied, 159.135 seconds, 659 MB/s
>> 200000+0 records in
>> 200000+0 records out
>> 104857600000 bytes (105 GB) copied, 1916.87 seconds, 54.7 MB/s
>> 
>> 
>> On Mar 1, 2013, at 9:58 AM, Thomas Wakefield <twake at iges.org> wrote:
>> 
>>> The max setting for performance.read-ahead-page-count is 16, which I did just try.  No significant change. 
>>> 
>>> Any other setting options?
>>> 
>>> 
>>> 
>>> On Feb 28, 2013, at 10:18 PM, Anand Avati <anand.avati at gmail.com> wrote:
>>> 
>>>> Can you try "gluster volume set <volname> performance.read-ahead-page-count 64" or some value higher or lower?
>>>> 
>>>> Avati
>>>> 
>>>> On Thu, Feb 28, 2013 at 7:15 PM, Thomas Wakefield <twake at iges.org> wrote:
>>>> Good point, forgot to set a blcoksize, here are the redone dd tests:
>>>> 
>>>> [root at cpu_crew1 ~]# dd if=/shared/working/benchmark/test.cpucrew1 of=/dev/null bs=128k
>>>> 40000+0 records in
>>>> 40000+0 records out
>>>> 5242880000 bytes (5.2 GB) copied, 65.4928 seconds, 80.1 MB/s
>>>> [root at cpu_crew1 ~]# dd if=/shared/working/benchmark/test.cpucrew1 of=/dev/null bs=1M
>>>> 5000+0 records in
>>>> 5000+0 records out
>>>> 5242880000 bytes (5.2 GB) copied, 49.0907 seconds, 107 MB/s
>>>> [root at cpu_crew1 ~]# dd if=/shared/working/benchmark/test.cpucrew1 of=/dev/null bs=4M
>>>> 1250+0 records in
>>>> 1250+0 records out
>>>> 5242880000 bytes (5.2 GB) copied, 44.5724 seconds, 118 MB/s
>>>> 
>>>> Still not impressive.
>>>> 
>>>> -Tom
>>>> 
>>>> 
>>>> On Feb 28, 2013, at 8:42 PM, Jeff Anderson-Lee <jonah at eecs.berkeley.edu> wrote:
>>>> 
>>>>> Thomas,
>>>>> 
>>>>> You have not specified a block size, so you are doing a huge number of small(ish) reads with associated round trips. What happens with dd bs=128k ..?
>>>>> 
>>>>> Jeff Anderson-Lee
>>>>> 
>>>>> On 2/28/2013 5:30 PM, Thomas Wakefield wrote:
>>>>>> Did a fresh dd test just to confirm, same results:
>>>>>> 
>>>>>> [root at cpu_crew1 benchmark]# dd if=/dev/zero of=/shared/working/benchmark/test.cpucrew1 bs=512k count=10000
>>>>>> 10000+0 records in
>>>>>> 10000+0 records out
>>>>>> 5242880000 bytes (5.2 GB) copied, 7.43695 seconds, 705 MB/s
>>>>>> [root at cpu_crew1 benchmark]# dd if=/shared/working/benchmark/test.cpucrew1 of=/dev/null
>>>>>> 552126+0 records in
>>>>>> 552125+0 records out
>>>>>> 282688000 bytes (283 MB) copied, 37.8514 seconds, 7.5 MB/s
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> On Feb 28, 2013, at 8:14 PM, Bryan Whitehead <driver at megahappy.net> wrote:
>>>>>> 
>>>>>>> How are you doing the reading? Is this still an iozone benchmark?
>>>>>>> 
>>>>>>> if you simply dd if=/glustermount/bigfile of=/dev/null, is the speed better?
>>>>>>> 
>>>>>>> 
>>>>>>> On Thu, Feb 28, 2013 at 5:05 PM, Thomas Wakefield <twake at iges.org> wrote:
>>>>>>> I get great speed locally, it's only when I add gluster in that it slows down.  I get 2GB/s locally to the exact same brick.  It's gluster that is having the read issue (80MB/s).  But Gluster can write just fine, 800MB/s.
>>>>>>> 
>>>>>>> The blockdev idea is a good one, and I have already done it.  Thanks though.
>>>>>>> 
>>>>>>> -Tom
>>>>>>> 
>>>>>>> On Feb 28, 2013, at 7:53 PM, Ling Ho <ling at slac.stanford.edu> wrote:
>>>>>>> 
>>>>>>>> Tom,
>>>>>>>> 
>>>>>>>> What type of disks do you have? If they are raid 5 or 6, have you try setting the read-ahead size to 8192 or 16384 (blockdev --setra 8192 /dev/<sd?>   ?
>>>>>>>> 
>>>>>>>> ...
>>>>>>>> ling
>>>>>>>> 
>>>>>>>> On 02/28/2013 04:23 PM, Thomas Wakefield wrote:
>>>>>>>>> 
>>>>>>>>> Did anyone else have any ideas on performance tuning for reads?
>>>>>>>>> 
>>>>>>>>> On Feb 27, 2013, at 9:29 PM, Thomas Wakefield <twake at iges.org> wrote:
>>>>>>>>> 
>>>>>>>>>> Bryan-
>>>>>>>>>> 
>>>>>>>>>> Yes I can write at 700-800MBytes/sec, but i can only read at 70-80 MBytes/sec.  I would be very happy if I could get it to read at the same speed it can write at.  And the 70-80 is sequential, not random for reads, same exact test commands on the disk server are in the 2+GB/s range, so I know the disk server can do it.
>>>>>>>>>> 
>>>>>>>>>> -Tom
>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>>> On Feb 27, 2013, at 7:41 PM, Bryan Whitehead <driver at megahappy.net> wrote:
>>>>>>>>>> 
>>>>>>>>>>> Are your figures 700-800MByte/sec? Because that is probably as fast as your 10G nic cards are able to do. You can test that by trying to push a large amount of data over nc or ftp.
>>>>>>>>>>> 
>>>>>>>>>>> Might want to try Infiniband. 40G cards are pretty routine.
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> On Wed, Feb 27, 2013 at 3:45 PM, Thomas Wakefield <twake at iges.org> wrote:
>>>>>>>>>>> I also get the same performance running iozone for large file sizes, iozone -u 1 -r 512k -s 2G -I -F.
>>>>>>>>>>> 
>>>>>>>>>>> Large file IO is what I need the system to do.  I am just shocked at the huge difference between local IO and gluster client IO.  I know there should be some difference, but 10x is unacceptable.
>>>>>>>>>>> 
>>>>>>>>>>> -Tom
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> On Feb 27, 2013, at 5:31 PM, Bryan Whitehead <driver at megahappy.net> wrote:
>>>>>>>>>>> 
>>>>>>>>>>>> Every time you open/close a file or a directory you will have to wait for locks which take time. This is totally expected.
>>>>>>>>>>>> 
>>>>>>>>>>>> Why don't you share what you want to do? iozone benchmarks look like crap but serving qcow2 files to qemu works fantastic for me. What are you doing? Make a benchmark that does that. If you are going to have many files with a wide variety of sizes glusterfs/fuse might not be what you are looking for.
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> On Wed, Feb 27, 2013 at 12:56 PM, Thomas Wakefield <twake at cola.iges.org> wrote:
>>>>>>>>>>>> I have tested everything, small and large files.  I have used file sizes ranging from 128k up to multiple GB files.  All the reads are bad.
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> Here is a fairly exhaustive iozone auto test:
>>>>>>>>>>>> 
>>>>>>>>>>>>                                                             random  random    bkwd   record   stride                                   
>>>>>>>>>>>>               KB  reclen   write rewrite    read    reread    read   write    read  rewrite     read   fwrite frewrite   fread  freread
>>>>>>>>>>>>               64       4   40222   63492    26868    30060    1620   71037    1572    70570    31294    77096    72475   14736    13928
>>>>>>>>>>>>               64       8   99207  116366    13591    13513    3214   97690    3155   109978    28920   152018   158480   18936    17625
>>>>>>>>>>>>               64      16  230257  253766    25156    28713   10867  223732    8873   244297    54796   303383   312204   15062    13545
>>>>>>>>>>>>               64      32  255943  234481  5735102  7100397   11897  318502   13681   347801    24214   695778   528618   25838    28094
>>>>>>>>>>>>               64      64  214096  681644  6421025  7100397   27453  292156   28117   621657    27338   376062   512471   28569    32534
>>>>>>>>>>>>              128       4   74329   75468    26428    41089    1131   72857    1118    66976     1597    73778    78343   13351    13026
>>>>>>>>>>>>              128       8  100862  135170    24966    16734    2617  118966    2560   120406    39156   125121   146613   16177    16180
>>>>>>>>>>>>              128      16  115114  253983    28212    17854    5307  246180    5431   229843    47335   255920   271173   27256    24445
>>>>>>>>>>>>              128      32  256042  391360    39848    64258   11329  290230    9905   429563    38176   490380   463696   20917    19219
>>>>>>>>>>>>              128      64  248573  592699  4557257  6812590   19583  452366   29263   603357    42967   814915   692017   76327    37604
>>>>>>>>>>>>              128     128  921183  526444  5603747  5379161   45614  390222   65441   826202    41384   662962  1040839   78526    39023
>>>>>>>>>>>>              256       4   76212   77337    40295    32125    1289   71866    1261    64645     1436    57309    53048   23073    29550
>>>>>>>>>>>>              256       8  126922  141976    26237    25130    2566  128058    2565   138981     2985   125060   133603   22840    24955
>>>>>>>>>>>>              256      16  242883  263636    41850    24371    4902  250009    5290   248792    89353   243821   247303   26965    26199
>>>>>>>>>>>>              256      32  409074  439732    40101    39335   11953  436870   11209   430218    83743   409542   479390   30821    27750
>>>>>>>>>>>>              256      64  259935  571502    64840    71847   22537  617161   23383   392047    91852   672010   802614   41673    53111
>>>>>>>>>>>>              256     128  847597  812329   185517    83198   49383  708831   44668   794889    74267  1180188  1662639   54303    41018
>>>>>>>>>>>>              256     256  481324  709299  5217259  5320671   44668  719277   40954   808050    41302   790209   771473   62224    35754
>>>>>>>>>>>>              512       4   77667   75226    35102    29696    1337   66262    1451    67680     1413    69265    69142   42084    27897
>>>>>>>>>>>>              512       8  134311  144341    30144    24646    2102  134143    2209   134699     2296   108110   128616   25104    29123
>>>>>>>>>>>>              512      16  200085  248787    30235    25697    4196  247240    4179   256116     4768   250003   226436   32351    28455
>>>>>>>>>>>>              512      32  330341  439805    26440    39284    8744  457611    8006   424168   125953   425935   448813   27660    26951
>>>>>>>>>>>>              512      64  483906  733729    48747    41121   16032  555938   17424   587256   187343   366977   735740   41700    41548
>>>>>>>>>>>>              512     128  836636  907717    69359    94921   42443  761031   36828   964378   123165   651383   695697   58368    44459
>>>>>>>>>>>>              512     256  520879  860437   145534   135523   40267  847532   31585   663252    69696  1270846  1492545   48822    48092
>>>>>>>>>>>>              512     512  782951  973118  3099691  2942541   42328  871966   46218   911184    49791   953248  1036527   52723    48347
>>>>>>>>>>>>             1024       4   76218   69362    36431    28711    1137   66171    1174    68938     1125    70566    70845   34942    28914
>>>>>>>>>>>>             1024       8  126045  140524    37836    15664    2698  126000    2557   125566     2567   110858   127255   26764    27945
>>>>>>>>>>>>             1024      16  243398  261429    40238    23263    3987  246400    3882   260746     4093   236652   236874   31429    25076
>>>>>>>>>>>>             1024      32  383109  422076    41731    41605    8277  473441    7775   415261     8588   394765   407306   40089    28537
>>>>>>>>>>>>             1024      64  590145  619156    39623    53267   15051  722717   14624   753000   257294   597784   620946   38619    44073
>>>>>>>>>>>>             1024     128 1077836 1124099    56192    64916   36851 1102176   37198  1082454   281548   829175   792604   47975    51913
>>>>>>>>>>>>             1024     256  941918 1074331    72783    81450   26778 1099636   32395  1060013   183218  1024121   995171   44371    45448
>>>>>>>>>>>>             1024     512  697483 1130312   100324   114682   48215 1041758   41480  1058967    90156   994020  1563622   56328    46370
>>>>>>>>>>>>             1024    1024  931702 1087111  4609294  4199201   44191  949834   45594   970656    56674   933525  1075676   44876    46115
>>>>>>>>>>>>             2048       4   71438   67066    58319    38913    1147   44147    1043    42916      967    66416    67205   45953    96750
>>>>>>>>>>>>             2048       8  141926  134567    61101    55445    2596   77528    2564    80402     4258   124211   120747   53888   100337
>>>>>>>>>>>>             2048      16  254344  255585    71550    74500    5410  139365    5201   141484     5171   205521   213113   67048    57304
>>>>>>>>>>>>             2048      32  397833  411261    56676    80027   10440  260034   10126   230238    10814   391665   383379   79333    60877
>>>>>>>>>>>>             2048      64  595167  687205    64262    87327   20772  456430   19960   477064    23190   540220   563096   86812    92565
>>>>>>>>>>>>             2048     128  833585  933403   121926   118621   37700  690020   37575   733254   567449   712337   734006   92011   104934
>>>>>>>>>>>>             2048     256  799003  949499   143688   125659   40871  892757   37977   880494   458281   836263   901375  131332   110237
>>>>>>>>>>>>             2048     512  979936 1040724   120896   138013   54381  859783   48721   780491   279203  1068824  1087085   97886    98078
>>>>>>>>>>>>             2048    1024  901754  987938    53352    53043   72727 1054522   68269   992275   181253  1309480  1524983  121600    95585
>>>>>>>>>>>>             2048    2048  831890 1021540  4257067  3302797   75672  984203   80181   826209    94278   966920  1027159  111832   105921
>>>>>>>>>>>>             4096       4   66195   67316    62171    74785    1328   28963    1329    26397     1223    71470    69317   55903    84915
>>>>>>>>>>>>             4096       8  122221  120057    90537    60958    2598   47312    2468    59783     2640   128674   127872   41285    40422
>>>>>>>>>>>>             4096      16  238321  239251    29336    32121    4153   89262    3986    96930     4608   229970   237108   55039    56983
>>>>>>>>>>>>             4096      32  417110  421356    30974    50000    8382  156676    7886   153841     7900   359585   367288   26611    25952
>>>>>>>>>>>>             4096      64  648008  668066    32193    29389   14830  273265   14822   282211    19653   581898   620798   51281    50218
>>>>>>>>>>>>             4096     128  779422  848564    55594    60253   37108  451296   35908   491361    37567   738163   728059   67681    66440
>>>>>>>>>>>>             4096     256  865623  886986    71368    63947   44255  645961   42689   719491   736707   819696   837641   57059    60347
>>>>>>>>>>>>             4096     512  852099  889650    68870    73891   31185  845224   30259   830153   392334   910442   961983   60083    55558
>>>>>>>>>>>>             4096    1024  710357  867810    29377    29522   49954  846640   43665   926298   213677   986226  1115445   55130    59205
>>>>>>>>>>>>             4096    2048  826479  908420    43191    42075   59684  904022   58601   855664   115105  1418322  1524415   60548    66066
>>>>>>>>>>>>             4096    4096  793351  855111  3232454  3673419   66018  861413   48833   847852    45914   852268   842075   42980    48374
>>>>>>>>>>>>             8192       4   67340   69421    42198    31740     994   23251    1166    16813      837    73827    73126   25169    29610
>>>>>>>>>>>>             8192       8  137150  125622    29131    36439    2051   44342    1988    48930     2315   134183   135367   31080    33573
>>>>>>>>>>>>             8192      16  237366  220826    24810    26584    3576   88004    3769    78717     4289   233751   235355   23302    28742
>>>>>>>>>>>>             8192      32  457447  454404    31594    27750    8141  142022    7846   143984     9322   353147   396188   34203    33265
>>>>>>>>>>>>             8192      64  670645  655259    28630    23255   16669  237476   16965   244968    15607   590365   575320   49998    43305
>>>>>>>>>>>>             8192     128  658676  760982    44197    47802   28693  379523   26614   378328    27184   720997   702038   51707    49733
>>>>>>>>>>>>             8192     256  643370  698683    56233    63165   28846  543952   27745   576739    44014   701007   725534   59611    58985
>>>>>>>>>>>>             8192     512  696884  776793    67258    52705   18711  698854   21004   694124   621695   784812   773331   43101    47659
>>>>>>>>>>>>             8192    1024  729664  810451   15470    15875   31318  801490   38123   812944   301222   804323   832765   54308    53376
>>>>>>>>>>>>             8192    2048  749217   68757    21914    22667   48971  783309   48132   782738   172848   907408   929324   51156    50565
>>>>>>>>>>>>             8192    4096  707677  763960    32063    31928   47809  751692   49560   786339    93445  1046761  1297876   48037    51680
>>>>>>>>>>>>             8192    8192  623817  746288  2815955  3137358   48722  741633   35428   753787    49626   803683   823800   48977    52895
>>>>>>>>>>>>            16384       4   72372   73651    34471    30788     960   23610     903    22316      891    71445    71138   56451    55129
>>>>>>>>>>>>            16384       8  137920  141704    50830    33857    1935   41934    2275    35588     3608   130757   137801   51621    48525
>>>>>>>>>>>>            16384      16  245369  242460    41808    29770    3605   75682    4355    75315     4767   241100   239693   53263    30785
>>>>>>>>>>>>            16384      32  448877  433956    31846    35010    7973  118181    8819   112703     8177   381734   391651   57749    63417
>>>>>>>>>>>>            16384      64  710831  700712    66792    68864   20176  209806   19034   207852    21255   589503   601379  104567   105162
>>>>>>>>>>>>            16384     128  836901  860867   104226   100373   40899  358865   40946   360562    39415   675968   691538   96086   105695
>>>>>>>>>>>>            16384     256  798081  828146   107103   120433   39084  595325   39050   593110    56925   763466   797859  109645   113414
>>>>>>>>>>>>            16384     512  810851  843931   113564   106202   35111  714831   46244   745947    53636   802902   760172  110492   100879
>>>>>>>>>>>>            16384    1024  726399  820219    22106    22987   53087  749053   54781   777705  1075341   772686   809723  100349    96619
>>>>>>>>>>>>            16384    2048  807772  856458    23920    23617   66320  829576   72105   740848   656379   864539   835446   93499   101714
>>>>>>>>>>>>            16384    4096  797470  840596    27270    28132   88784  834938   83428   836809   342898   953274   969699   96499   100657
>>>>>>>>>>>>            16384    8192  760063  812942    41022    40014  102020  812135  104063   820346   229870  1252409  1398306  100959   103793
> ...
> 
> [Message clipped]  
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