[Gluster-users] Gluster High CPU/Clients Hanging on Heavy Writes

Raghavendra Gowdappa rgowdapp at redhat.com
Sun Aug 5 07:38:48 UTC 2018

On Sun, Aug 5, 2018 at 12:44 PM, Yuhao Zhang <zzyzxd at gmail.com> wrote:

> Hi,
> I am running into a situation that heavy write causes Gluster server went
> into zombie with many high CPU processes and all clients hangs, it is
> almost 100% reproducible on my machine. Hope someone can help.

Can you give us the output of monitioring these processes with High cpu
usage captured in the duration when your tests are running?

- MON_INTERVAL=10 # can be increased for very long runs
- top -bd $MON_INTERVAL > /tmp/top_proc.${HOSTNAME}.txt # CPU utilization
by process
- top -bHd $MON_INTERVAL > /tmp/top_thr.${HOSTNAME}.txt # CPU utilization
by thread

> I started to observe this issue when running rsync to copy files from
> another server and I thought it might be because Gluster doesn't like
> rsync's delta transfer with a lot of small writes. However, I was able to
> reproduce this with "rsync --whole-file --inplace", or even with cp or scp.
> It usually appears after starting the transfer for a few hours, but
> sometimes can happen within several minutes.
> Since this is a single node Gluster distributed volume, I tried to
> transfer files directly onto the server bypassing Gluster clients, but it
> still caused the same issue.
> It is running on top of a ZFS RAIDZ2 dataset. Options are attached. Also,
> I attached the statedump generated when my clients hung, and volume options.
> - Ubuntu 16.04 x86_64 / 4.4.0-116-generic
> - GlusterFS 3.12.8
> Thank you,
> Yuhao
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> https://lists.gluster.org/mailman/listinfo/gluster-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gluster.org/pipermail/gluster-users/attachments/20180805/cb370904/attachment.html>

More information about the Gluster-users mailing list