[Gluster-devel] FOP ratelimit?

[Venky Shankar]

On Wed, Sep 2, 2015 at 1:59 PM, Emmanuel Dreyfus <manu at netbsd.org> wrote:
> Hi
>
> Yesterday I experienced the problem of a single user bringing down
> a glusterfs cluster to its knees because of a high amount of rename
> operations.
>
> I understand rename on DHT can be very costly because data really have
> to be moved from a brick to another one just for a file name change.
> Is there a workaround for this behavior?

Not really. DHT uses pointer files (so called link-to) to work around
moving file contents on rename().

>
> And more generally, do we have a way to ratelimit FOPs per client, so
> that one client cannot make the cluster unusable for the others?

There is some form of limiting based on priority (w/ client-pids) in
io-threads. For bit-rot, I had used token bucket
based throttling[1] during hash calculation. But that resides on the
client side for bitrot xlator. It may be beneficial
to have that on the server side.

>
> --
> Emmanuel Dreyfus
> manu at netbsd.org
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