[Gluster-users] Increased performance for small files with debug/trace translator?

Jeff Darcy
Tue, 03 Aug 2010 19:49:27 -0000

On 08/03/2010 10:24 AM, Major Hayden wrote:
> Initial test with my normal client volfile:
>   Client volfile: http://pastie.org/1072935
>   untar: 32.999s
>   removal: 4.540s
>
> Second test with debug/trace translator enabled:
>   Client volfile: http://pastie.org/1072951
>   untar: 6.077s
>   removal: 1.806s
>
> ...
>
> If anyone has any ideas, I'm all ears.

Major, Ed Wyse, and I figured this one out on IRC.  It turns out that
when the trace translator is enabled in the client volfile, it becomes
the lowest and thus the one that's mounted . . . but it goes straight to
server01 bypassing (among other things) mirror-0.  In most cases this
would result in a "dangling volume" error, but there's a bit of a
bug in
that the only real dangling volume is iocache and that particular
translator - unlike most - doesn't produce a warning.