Killer Micro Question

[Ian Dall]

In article <16364 at s.ms.uky.edu> randy at ms.uky.edu (Randy Appleton) writes:
>But how does each user, who is about to log in, know which machine to
>log into?  He ought to log into the one with the lowest load average, yet
>without logging on cannot determine which one that is.

I do just that! I have a little shell script called "least-loaded"
which grunges through the output of ruptime. So when X starts up it
does "rsh `least-loaded <list of servers>` ...." to start my clients.
I also do this when I have a compute bound job to run.

The only catch is that all servers need to be capable of running your
job. We have several servers set up with NFS cross mounting so they
are *almost* identical. You can get caught out sometimes though.
Also, NFS imposes an additional overhead. Running a compute bound
process this way is fine, running an IO bound process this way might
be a bad idea if the disk it accesses is physically on another server.

In short, I think it is a good idea, but it needs a more efficient
distributed file system before I would want to release it on Joe User.
It would be really nice to have a distributed OS which was able to
migrate IO bound processes to minimise network traffic and migrate
cpu bound processes to the least loaded machine. Dream on!

-- 
Ian Dall     life (n). A sexually transmitted disease which afflicts
                       some people more severely than others.