[Swift-user] Re: swift on jazz

[Michael Wilde]

Hi Marcin,

I took the liberty of moving this thread to swift-user for others to 
help me answer you, and for other users to benefit.

On Jazz, are you observing that Swift only puts at most 2 jobs in the 
Jazz PBS queue (where you can see them with "qstat") or that Swift puts 
many jobs in the queue but only 2 run at a time?

Assuming its the latter, you must be bumping in Jazz's scheduler policy 
which is favoring multi-CPU jobs. If thats the case, then lets try 
running the "coaster" provider which is specified in the sites.xml file. 
(tc.data doesnt change).

First, change your "jazz" entry in sites.xml from the PBS execution 
provider:

   <execution provider="pbs" url="none" />

to the Coaster provider:

   <execution provider="coaster" url="none" jobmanager="pbs:local" />

This should work, although we may need to add additional XML 
specifications for timilimits, accounts, and maybe queues.

Then we expect to be applying a fix to the coaster rpovider tonight, so 
we'll need to do a custom Swift build from the source repository after 
that, and test the latest fix. The fix improves the throughput, but even 
without it, you should see Swift requesting more CPUs from PBS in a 
single job.

I suggest getting started with this simple change, and we'll enhance it 
  in stages to give you better performance and more parallelism.

- Mike


On 8/26/09 3:20 PM, Marcin Hitczenko wrote:

> ... I am running jobs on jazz and I noticed that jazz will only run
> at most two jobs at once for me (I have about 30), even though there are
> more nodes free and I am requiring only one node per job. Is there
> something I can do to change this? Would I have to change the tc.data or
> sites.xml file?
> 
> Thanks,
> 
> Marcin