[Bioclusters] Clueless about Mosix

[Ivo Grosse]

Chris Dagdigian <dag@sonsorol.org> wrote on Mon, 13 May 2002:

> It would be counter productive if they were not aware of each other -- 
> if they played nicely together then there is certainly a place for batch 
> scheduling in a MOSIX-type environment.

I have a few naive (and losely coupled) questions:

1. even if Mosix and the scheduler were aware of each other, but would 
operate on the same time scale, then that could (theoretically) lead to 
terrible confusion (oscillations, resonance, even chaos ... in the 
sense of nonlinear dynamics and chaos theory), correct?  Do those 
phenomena occur in reality?  What are the time scales of Mosix and 
typical schedulers, say, SGE?  I mean:

- how often does Mosix check the state of the nodes?  (Once every 
second?)

- how often does SGE check the state of the nodes?

- how long does it take a process to be migrated, or to be started?

2. can Mosix be used without a scheduler?  I mean: assume we start 
100,000 jobs on a 100-nodes cluster.  Is Mosix smart enough to start 
only 100 jobs and keep the others in a queue?

3. if Mosix is not smart enough to do job queuing, then I think there 
*must* be schedulers that work together with Mosix.  Hi Mosix users, 
which schedulers do you use?  Did you encounter any confusion phenomena 
(see question 1.) where the scheduler and Mosix trick each other?

A Mosix-unrelated question:

4. SGE is capable of rearranging jobs in the queue according to 
priority.  But is SGE capable of stopping already running jobs if 
higher-priority jobs are in the queue?  If not, which schedulers can do 
that?

Best regards, Ivo