[torqueusers] random node selection using maui?

[Lennart Karlsson]

wyckoff at yahoo-inc.com said:
> I have a largish cluster (~3K nodes) and I want the ability to
> allocate  a random N nodes on the cluster.  The maui documentation
> says that  FASTEST allocation with no attributes is random, but it
> isn't.  Is there  another way to do this? 

Peter,

As far as I know, you have to do the randomization yourself. The first
three ways that comes to my mind is:

1/ Change the Maui code to add a randomization parameter. The hard way.

2/ Stop Maui, stop Torque, randomize the node ordering in the Torque
configuration file "nodes", start Torque, and start Maui, in that
sequence. A lot of restarts of the applications so it is not at all
practical if you need to do it more than a few times. But you have not
told us why you want the randomization: If you actually just want to
schedule the nodes in a different order, you can reorder the "nodes"
file once in whatever way you want and be happy ever after. :-)

3/ Choose a number of random node names from your cluster and give
those node names as qsub parameters, e.g.

	qsub -l nodes=n125+n2836+n1583 scriptfile


Best wishes,
-- Lennart Karlsson <Lennart.Karlsson at nsc.liu.se>
   National Supercomputer Centre in Linkoping, Sweden
   http://www.nsc.liu.se