[Gluster-users] High latency on FSYNC, INODELK, FINODELK

[Paul E Stallworth]

Hello,

I ran a gluster volume profile while doing a dd to read from /dev/zero and write to a file and noticed unusually high latency on the FSYNC, INODELK, and FINODELK operations.  This latency seems to correspond with very slow page loads of our website.  I'm looking for any help in finding where this latency might be coming from and how we might mitigate it. 

Here are the values from the profile

%-latency Avg-latency Min-Latency Max-Latency No. of calls Fop
--------- ----------- ----------- ----------- ------------ ----
0.00 0.00 us 0.00 us 0.00 us 110601 FORGET
0.00 0.00 us 0.00 us 0.00 us 104872 RELEASE
0.00 0.00 us 0.00 us 0.00 us 269678 RELEASEDIR
0.00 50.00 us 45.00 us 55.00 us 2 OPEN
0.00 73.50 us 32.00 us 115.00 us 2 FLUSH
0.00 47.00 us 33.00 us 57.00 us 4 ENTRYLK
0.00 226.00 us 226.00 us 226.00 us 1 CREATE
0.00 83.75 us 42.00 us 136.00 us 4 STATFS
0.00 72.80 us 23.00 us 175.00 us 5 READDIR
0.00 54.90 us 15.00 us 97.00 us 10 GETXATTR
0.00 79.19 us 26.00 us 193.00 us 32 FXATTROP
0.00 45.36 us 14.00 us 271.00 us 206 STAT
0.01 66.26 us 2.00 us 586.00 us 352 OPENDIR
0.09 252262.00 us 252262.00 us 252262.00 us 1 UNLINK
1.02 139.54 us 29.00 us 10777.00 us 20263 WRITE
7.98 1843032.83 us 22261.00 us 16023044.00 us 12 FSYNC
8.19 1620932.64 us 27.00 us 17171453.00 us 14 INODELK
9.03 94.52 us 22.00 us 9533.00 us 264526 LOOKUP
73.67 563743.05 us 14.00 us 17173239.00 us 362 FINODELK

Thanks,
Paul

Paul Stallworth
Housing Information Technology
University of Colorado Boulder
Boulder, Colorado 80309
T 303.735.6623
M 303.735.6623