[OpenAFS] Re: Investigating 'calls waiting' from rxdebug

drosih@rpi.edu drosih@rpi.edu
Sun, 18 Aug 2013 21:11:41 -0400

On Sun, 18 Aug 2013, Andrew Deason wrote:
> On Sat, 17 Aug 2013, drosih@rpi.edu wrote:
> > Can I just edit /usr/afs/local/BosConfig with 'vi' and add the '-p'
> > value to the 'parm' line for the fileserver?  And then do
> >       bos shutdown <server> -wait -localauth
> >       bos startup <server> -localauth
> > to make it actually happen?
> No, don't do that.

I tried it.  It didn't work.  I undid the change to the file.  I wasn't
too surprised that it didn't work.  I ended up not trying to increase
the value this weekend, for a variety of reasons (including a killer
headache as I was staring at the monitor).

What I intended to do, once I get good timeframe to do it in:

  bos status $HNAME -long -localauth
  bos stop   $HNAME -wait -localauth
  bos delete $HNAME fs    -localauth
  bos create $HNAME fs fs "/usr/afs/bin/fileserver -L -p 192" ...etc...
  bos status $HNAME -long -localauth

> You should probably set at least '-L -p 128' if you have no other
> options set. -L sets a few other options besides -p.

Well.  Interesting!  We have been running with '-L' set.  I looked
at an AFS Admin guide which said the threads value for '-L' *was*
128, so I was going to increase it to 192.  Obviously the Admin
guide that I'm looking at is much newer than the version of OpenAFS
that I'm running!

If I'm reading the source code for 1.4.6 correctly, '-L' is giving me
12 threads.  That doesn't seem possible!!  Looking closer at the
output of 'rxdebug -rxstats' on the recently-restarted server, I see:

    0 calls waiting for a thread
   14 threads are idle
    3 calls have waited for a thread

So that sounds like the limit really is somewhere around 12.  Ouch!

I could go with adding '-p 96' and it'd be a huge improvement!

Garance Alistair Drosehn
Senior Systems Programmer
Rensselaer Polytechnic Institute;  Troy NY