[OpenAFS] client tuning using the -daemons option

[Jason Edgecombe]

David,

It wasn't any formal benchmarking, it was the informal "pages takes 10 
seconds to load, gotta fix that". I tweaked things until I wasn't 
drumming my fingers waiting on pages to load.

Our production solaris web server runs with 6 daemons and 1000 stat 
entries just fine. The problem server was a vmware guest under vmware 
server 1.x running RHEL5.0 i386 with openafs 1.4.7. I haven't ruled out 
VMware as a performance killer, but I made things tolerable with the 
following options to afsd: "-daemons 16 -stat 50000 -volumes 1000". The 
most significant change was the daemons option, followed by the stat 
option. Increasing the cache from 100M to 1.3GB didn't help much without 
the other options.

I hope that helps.

Jason

David R Boldt wrote:
> Jason,
>
> We are running Web servers on top of AFS, and I am
> curious what you've discovered in your benchmarking.
>
> Our systems are Sparc Solaris, but it seems that these
> tuning issues would not be architecture specific.
>
>
>                                          -- David Boldt
>                                              <dboldt@usgs.gov>
>
>
>    "Charm is the quality in others that makes us more satisfied with 
> ourselves."
>     --Henri-Frédéric Amiel
>
>
>
>
>
> "Derrick Brashear" <shadow@gmail.com> 
> Sent by: openafs-info-admin@openafs.org
> 11/11/2008 04:44 PM
>
> To
> OpenAFS-info@openafs.org
> cc
>
> Subject
> Re: [OpenAFS] client tuning using the -daemons option
>
>
>
>
>
>
> More daemons means more background fetching and storing, which means
> more in-flight requests at any given time. Any one authentication
> context can have only 4 calls per server at a time, but for a web
> server you probably can use more than just 2 sets of extra calls worth
> of daemons.
>
>
> On Tue, Nov 11, 2008 at 12:00 PM, Jason Edgecombe
> <jason@rampaginggeek.com> wrote:
>   
>> hi everyone,
>>
>> I'm tuning some afs client settings for our Linux 64bit workstations
>> (v1.4.7) and for a test Linux web server (v1.4.6). I noticed that
>> bumping the -daemons option for afsd from 6 to 16 on the web server
>> seems to improve performance along with increasing the stat and volume
>> cache. Increasing the daemons option gave the most improvement.
>>
>> The afsd man pages says that more than 6 daemons should not be needed,
>> but my experiment seems to prove otherwise. What are the pros and cons
>> of running with more alfsd daemons configured? Should the man page be
>> updated to recommend running more daemons?
>>
>> What metrics can I use besides my applications run time to see that the
>> client is optimized properly? xstat_fs_cache gives me so much data that
>> it's confusing. How do I tell when increasing stat, volume, and daemons
>> options would improve performance?
>>     
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