Newsgroups: comp.parallel.pvm
From: bjo@fwi.uva.nl (Benno Overeinder)
Subject: Re: Load Balancing heuristic
Organization: FWI, University of Amsterdam
Date: 4 Jul 1995 14:12:24 +0200
Message-ID: <3tbb78$97k@word.fwi.uva.nl>

Matematicas Discretas <md17> writes:

>We're a Parallel Processing Research group and we're interested in Load
>Balancing Optimization with PVM.

>In PVM 3 USER'S GUIDE AND REFERENCE MANUAL, Appendix A, page 150 it was
>mentioned a heuristic used to distribute the ntask processes across the Virtual
>Machine.

>Could you please give us a reference about the criteria used in this heuristic?

As far as I know, the current heuristic is a round-robin scheduling 
strategy, thus tasks are evenly distributed over the avaibable hosts.
But, this simple scheme does not fully optimize the utilization of the 
pool of hosts.

There are some initiatives to elevate this problem.  For example, there 
is CARMI (PVM-Condor interface developed by Miron Livny et al.), that
uses the Condor resource management services.  The CARMI service is
not transparent to the user in the sense that a task can be suspended
and killed by the resource manager.   Tasks which have requested 
notification are notified.  See for more information: 
http://www.cs.wisc.edu/condor/

Another way to go are fully transparent (dynamic) load balancing services,
such as provided by MPVM and DynamicPVM.  These run-time support systems
are transparent to the PVM program, thus no changes are necessary to
exploit the dynamic load balancing services.  These run-time support
systems use checkpoint-restart mechanism to migrate tasks from one
host to another.  For more information on MPVM, see URL:
http://www.cse.ogi.edu/DISC/projects/mist/
and for DynamicPVM (own plug ;-), see URL:
http://www.fwi.uva.nl/research/pwrs/papers/group.html
and search for string "dynamic", cause publication list is quite long.


Benno
-- 
 Benno Overeinder			 Computer Systems Department	     
 voice: (+31) 20 525 7536		 University of Amsterdam	    
 fax:   (+31) 20 525 7490		 Kruislaan 403, 1098 SJ  Amsterdam
 e-mail: bjo@fwi.uva.nl		 	 The Netherlands

