[Gluster-devel] CPU usage in AFR

Vikas Gorur vikas at gluster.com
Mon Dec 28 09:48:35 UTC 2009

Gordan Bobic wrote:
> Hi,
> I'm noticing something that could be considered weird. I have a 3-node 
> rootfs-on-gluster cluster, and I'm doing a big yum update on one of 
> the nodes. On that node and one of the other nodes, glusterfsd is 
> using about 10-15% CPU. But on the 3rd node, glusterfs is using < 0.3% 
> CPU.
> I'm guessing this has something to do with the way locking backup and 
> fail-over is implemented (IIRC there is a master and a backup 
> lock/state server, rather than replicating this information to all the 
> servers). Can anyone hazard a guess and confirm or deny the possible 
> cause of this discrepancy?
Hm, this is indeed a little strange. The first subvolume is used as the lock
server, so that could possibly explain why one of the servers have 
higher CPU
usage. However, this doesn't explain why *two* of the servers have high 
CPU usage.

Are you sure it is not the case that the *client* on one node (I'm assuming
all your three nodes act as servers and clients) and the server on 
another node
are using CPU?


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