[Gluster-users] Giving up [ was: Re: read-subvolume]

[Joe Landman]

On 07/10/2013 02:36 PM, Joe Julian wrote:

> 1) http://www.solarflare.com makes sub microsecond latency adapters that
> can utilize a userspace driver pinned to the cpu doing the request
> eliminating a context switch

We've used open-onload in the past on Solarflare hardware.  And with 
GlusterFS.

Just say no.  Seriously.  You don't want to go there.

> 2) http://www.aristanetworks.com/en/products/7100t is a 2.5 microsecond
> switch

Neither choice will impact overall performance much for GlusterFS, even 
in heavily loaded situations.

What impacts performance more than anything else is node/brick design, 
implementation, and specific choices in that mix.  Storage latency, 
bandwidth, and overall design will be more impactful than low latency 
networking.  Distribution, kernel and filesystem choices (including 
layout, lower level features, etc.) will matter significantly more than 
low latency networking.  You can completely remove the networking impact 
by trying your changes out on localhost, and seeing what the impact your 
design changes have.

If you don't start out with a fast box, you are not going to have fast 
aggregated storage.  This observation has not changed since the pre 2.0 
GlusterFS days (its as true today as it was years ago).

-- 
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics, Inc.
email: landman at scalableinformatics.com
web  : http://scalableinformatics.com
        http://scalableinformatics.com/siflash
phone: +1 734 786 8423 x121
fax  : +1 866 888 3112
cell : +1 734 612 4615