[Gluster-devel] One client can effectively hang entire gluster array

[Jeff Darcy]

> > * We might be able to tweak io-threads (which already runs on the
> > bricks and already has a global queue) to schedule requests in a
> > fairer way across clients. Right now it executes them in the
> > same order that they were read from the network.
> 
> This sounds to be an easier fix. We can make io-threads to factor in another
> input i.e., the client through which request came in (essentially
> frame->root->client) before scheduling. That should make the problem
> bearable at-least if not crippling. As to what algorithm to use, I think we
> can consider leaky bucket of bit-rot implementation or dmclock. I've not
> really thought deeper about the algorithm part. If the approach sounds ok,
> we can discuss more about algos.

I've created a patch to address the most basic part of this, in the simplest
way I could think of.

http://review.gluster.org/#/c/14904/

It's still running through basic tests, so I don't even know if it's really
correct yet, but it should give an idea of the conceptual direction.