Newsgroups: comp.parallel.pvm
From: adilger@enel.ucalgary.ca (Andreas Dilger)
Subject: Re: [Q] group server
Organization: ECE Department, U. of Calgary, Calgary, Alberta, Canada
Date: 9 Oct 1995 21:50:35 GMT
Message-ID: <45c5fb$1n7k@ds2.acs.ucalgary.ca>

In article <45b7bf$94q@prakinf2.PrakInf.TU-Ilmenau.DE>,
Gero Maeder <Gero.Maeder@e-technik.tu-ilmenau.de> wrote:
>I have some problems with finding a clever way to start up
>a group server on a specific machine.
>
>Inside a PVM-application different (in speed and memory) SPARC are included.
>However the group server is an additional load which should not run
>on the slowest machine, while the faster one are waiting idle in front
>of an barrier or something similar.
>Is there a way to start the group server on a specific machine??

This is similar to the situation that I am in.  We have SPARC 1+ on the
same network as SPARC 20s, so there is a large difference in speed.

If you set the speeds in the pvm.hosts file (ie sp=xxxx for each machine),
then you can use these values to determine which host is the fastest
(or at least one that is fast enough) via pvm_config().  Since the
default speed is 1000, you should set the speed on the "fast enough"
systems higher than this.

However, since these speeds are static, it may be that you want to do some
trivial calculation a number of times at startup to calibrate the speed
dynamically.  Depending on your application, and the relative speeds of
the systems, it may be that the static speed setting will be enough.

Cheers, Andreas.

-- 
Andreas Dilger   University of Calgary  \"If a man ate a pound of pasta and
(403) 220-8792   Micronet Research Group \ a pound of antipasto, would they
Dept of Electrical & Computer Engineering \   cancel out, leaving him still
http://www-mddsp.enel.ucalgary.ca/People/adilger/       hungry?" -- Dogbert

