[Gluster-users] NFS availability

[Stephan von Krawczynski]

On Thu, 31 Jan 2013 16:00:38 -0500
Jeff Darcy <jdarcy at redhat.com> wrote:

> > Most common network errors are not a matter of design, but of dead
> > iron.
> 
> It's usually both - a design that is insufficiently tolerant of
> component failure, plus a combination of component failures that exceeds
> that tolerance.  You seem to have a very high standard for filesystems
> continuing to maintain 100% functionality - and I suppose 100%
> performance as well - if there's any possibility whatsoever that they
> could do so.  Why don't you apply that same standard to the part of the
> system that you're responsible for designing?  Running any distributed
> system on top of a deficient network infrastructure will lead only to
> disappointment.

I am sorry that glusterfs is part of the design and your critics. 
Everyone working sufficiently long with networks of all kinds of sizes and
components can tell you that in the end you want a design for a file service
that works as long as possible. This means it should survive even if there is
only one client and server and network path left.
At least that is what is expected from glusterfs. Unfortunately sometimes you
get disappointed. We saw just about everything happening when switching off
all but one reliable network path including network hangs and server hangs
(the last one) (read the list for examples by others).
On the other end of the story clients see servers go offline if you increase
the non-gluster traffic on the network. Main (but not only) reason is the very
low default ping time (read the list for examples by others).
All these seen effects show clearly that noone ever tested this to an extent I
would have done writing this kind of software. After all this is a piece of
software whose merely only purpose is surviving dead servers and networks.
It is no question of design, because on paper everything looks promising.

Sometimes your arguments let me believe you want glusterfs working like a ford
car. A lot of technical gameplay built in but the idea that a car should be a
good car in the first place got lost on the way somewhere. Quite a lot of the
features built in lately have the quality of an mp3-player in your ford. Nice
to have but does not help you a lot driving 200 and a rabbit crossing.
And this is why I am requesting the equivalent of a BMW.

-- 
Regards,
Stephan