[Gluster-users] glusterfs performance issues

[Dennis Jacobfeuerborn]

Hi,
I'm running into performance trouble when using a simple replicated
glusterfs volume for a webserver. Specifically I set up two webservers with
an additional partition each for glusterfs 3.3.1. I formated the partitions
with xfs, created a simple replicated volume and mounted it on /mnt/data.

The issue is that the CMS running on the webserver creates resized versions
for images for the pages using GraphicsMagick and I see lots of "gm
convert" processes piling up and the gluster daemons show high cpu usage.
When I cd into one of the image directories and then type e.g.
"image1234.jp" <tab> the shell freezes for a minute before finally
completing the filename with the expected "g" at the end.

The "gm convert" processes make almost no progress even though on a regular
filesystem each call takes only a fraction of a second.

I looks like some sort of locking issue or something else that prevents
these processes or the bash completion from finishing in a reasonable
amount of time.

I've also written a small script that uses 50 parallel dd write processes
but cannot replicate the behavior with that. Here all the processes seem to
behave normally.

Any ideas what the problem could be and what I could do to make glusterfs
behave in a less erratic manner?

Regards,
  Dennis