[Gluster-users] Throughout over infiniband

[Stephan von Krawczynski]

On Mon, 10 Sep 2012 09:44:26 +0100
Brian Candler <B.Candler at pobox.com> wrote:

> On Mon, Sep 10, 2012 at 10:03:14AM +0200, Stephan von Krawczynski wrote:
> > > Yes - so in workloads where you have many concurrent clients, this isn't a
> > > problem.  It's only a problem if you have a single client doing a lot of
> > > sequential operations.
> > 
> > That is not correct for most cases. GlusterFS always has a problem on clients
> > with high workloads. This obviously derives from the fact that the FS is
> > userspace-based. If other userspace applications eat lots of cpu your FS comes
> > to a crawl.
> 
> It's only "obvious" if your application is CPU-bound, rather than I/O-bound.

I think one can drop the 5% market share that uses storage only for storing
_big_ files from client boxes with zero load. This is about the only case
where GlusterFS works ok if you don't mind the throughput problem of FUSE at
high rates.
If you have small files you are busted, if you have workload on the clients
you are busted and if you have lots of concurrent FS action on the client you
are busted. Which leaves you with test cases nowhere near real life.
I replaced nfs servers with glusterfs and I know what's going on in these
setups afterwards. If you're lucky you reach something like 1/3 of the NFS
performance.

-- 
Regards,
Stephan