[Gluster-devel] uss.t in master doing bad things to our regression test VM's

[Justin Clift]

Hi Vijaikumar,

As part of investigating what is going wrong with our VM's in Rackspace,
I created several new VM's (11 of them) and started a full regression
test run on them.

They're all hitting a major problem with uss.t.  Part of it does a "cat"
on /dev/urandom... which is taking several hours at 100% of a cpu. :(

Here is output from "ps -ef f" on one of them:

root  12094  1287  0 13:23 ? S   0:00  \_ /bin/bash /opt/qa/regression.sh
root  12101 12094  0 13:23 ? S   0:00      \_ /bin/bash ./run-tests.sh
root  12116 12101  0 13:23 ? S   0:01          \_ /usr/bin/perl /usr/bin/prove -rf --timer ./tests
root    382 12116  0 14:13 ? S   0:00              \_ /bin/bash ./tests/basic/uss.t
root   1713   382  0 14:14 ? S   0:00                  \_ /bin/bash ./tests/basic/uss.t
root   1714  1713 96 14:14 ? R 166:31                      \_ cat /dev/urandom
root   1715  1713  2 14:14 ? S   5:04                      \_ tr -dc a-zA-Z
root   1716  1713  9 14:14 ? S  16:31                      \_ fold -w 8

And from top:

top - 17:09:19 up  3:50,  1 user,  load average: 1.04, 1.03, 1.00
Tasks: 240 total,   3 running, 237 sleeping,   0 stopped,   0 zombie
Cpu0  :  4.3%us, 95.7%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  :  8.1%us, 15.9%sy,  0.0%ni, 76.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   1916672k total,  1119544k used,   797128k free,   114976k buffers
Swap:        0k total,        0k used,        0k free,   427032k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 1714 root      20   0 98.6m  620  504 R 96.0  0.0 169:00.94 cat
  137 root      20   0 36100 1396 1140 S 15.9  0.1  37:01.55 plymouthd
 1716 root      20   0 98.6m  712  616 S 10.0  0.0  16:46.55 fold
 1715 root      20   0 98.6m  636  540 S  2.7  0.0   5:08.95 tr
    9 root      20   0     0    0    0 S  0.3  0.0   0:00.59 ksoftirqd/1
    1 root      20   0 19232 1128  860 S  0.0  0.1   0:00.93 init
    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd

Your name is on the commit which added the code, but that was months ago.

No idea why it's suddenly being a problem.  Do you have any idea?

I am going to shut down all of these new test VM's except one, which I can
give you (or anyone) access to, if that would help find and fix the problem.

Btw, this is pretty important. ;)

+ Justin

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GlusterFS - http://www.gluster.org

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