Re: [MooseFS-Users] Performance suggestions for millions of small files

[Remolina, D. J <dij...@ae...>]

Hi Steve,


I have by no means a similar amount of files and space, as I am just testing, but this is what I see with MooseFS 4.6.0 and goal=3 on a pretty new (in testing phase, no load) 3-way server setup:


time tar -xf linux-4.9-rc3.tar

real    4m0.332s
user    0m1.668s
sys     0m9.517s

python /tmp/smallfile/smallfile_cli.py --operation create --threads 8 --file-size 1 --files 2048 --top /nethome/dijuremo/test

total threads = 8
total files = 15948
total IOPS = 15948
total data =     0.015 GiB
97.34% of requested files processed, minimum is  90.00
elapsed time =    11.608
files/sec = 1373.870032
IOPS = 1373.870032
MiB/sec = 1.341670


python /tmp/smallfile/smallfile_cli.py --operation read --threads 8 --file-size 1 --files 2048 --top /nethome/dijuremo/test

total threads = 8
total files = 16384
total IOPS = 16384
total data =     0.016 GiB
100.00% of requested files processed, minimum is  90.00
elapsed time =     2.553
files/sec = 6416.909838
IOPS = 6416.909838
MiB/sec = 6.266514

python /tmp/smallfile/smallfile_cli.py --operation append --threads 8 --file-size 1 --files 2048 --top /nethome/dijuremo/test


total threads = 8
total files = 15348
total IOPS = 15348
total data =     0.015 GiB
93.68% of requested files processed, minimum is  90.00
elapsed time =     8.018
files/sec = 1914.272783
IOPS = 1914.272783
MiB/sec = 1.869407



[cid:d2ba5e5d-face-451f-84da-62b3e8282ebc]


I will be happy to adjust the smallfile test settings if any of my tests are useful to you and re-run them for comparison.


Diego

________________________________
From: Wilson, Steven M <st...@pu...>
Sent: Thursday, October 18, 2018 4:47:14 PM
To: MooseFS-Users
Subject: [MooseFS-Users] Performance suggestions for millions of small files


Hi,


We have ten different MooseFS installations in our research group and one, in particular, is struggling with poor I/O performance.  This installation currently has 315 million files occupying 170TB of disk space (goal = 2).  If anyone else has a similar installation, I would like to hear what you have done to maintain performance at a reasonable level.


Here are some metrics to give a basic idea of the performance characteristics.  I'll include in parentheses the range of measurements from other MFS installations with far fewer files for comparison.

    * tar xf linux-4.9-rc3.tar: 1185 secs (220 - 296 secs)

    * smallfile test, create MB/s: 0.8 (2.3 - 4.8)  <== Ouch!

    * smallfile test, read MB/s: 10.7 (12.8 - 15.4)

    * smallfile test, append MB/s: 6.1 (3.0 - 7.7)


It looks file creation is where I'm losing most of my performance compared to the other installations.  My master server has a Xeon E5-1630v3 3.7GHz CPU with 256GB of DDR4 2133MHz memory.


I tried several mfsmount options but the only one that showed any significant improvement was the mfsfsyncmintime option ("mfsfsyncmintime=5").  As to be expected, the improvement gained was during the write/append operation.  Here are the results using the same tests as above:

    * tar xf linux-4.9-rc3.tar: 683 secs
    * smallfile test, create MB/s: 1.2
    * smallfile test, read MB/s: 11.7
    * smallfile test, append MB/s: 11.4  <== Dramatic improvement over 6.1 MB/s


The smallfile benchmark test I used is ​from https://github.com/distributed-system-analysis/smallfile.


Thanks for any suggestions you might have!


Regards,

Steve