Newsgroups: comp.parallel.pvm
From: dwhite@mrj.com (David White)
Subject: Re: Connecting multiple users
Organization: MRJ, Inc./Oakton, Virginia, USA
Date: 7 Sep 1995 16:20:34 -0400
Message-ID: <42nk6i$61o@frog.mrj.com>

Vernard MArtin says:
> Basically, I don't see how users can use PVM to connect to a PVM virtual
> machine unless it is already running. Its the chicken-egg thingy all over
> again. Now you could write some socket level code that does the initial
> handshaking but that would defeat the purpose of using PVM to start with.

Well, I got around this problem in a rather sleazy way, I guess, but it
works.  When the program needing PVM starts, if PVM isn't there, it snoops
around the net to see if a daemon is up, and if so, spawns a process on
that computer which requests the original host be added to the parallel
virtual machine.  If no daemons are found, it starts PVM itself.

The only work-arouond for the single UID requirement PVM has is to create
all the executables used in the system with a common UID, and with the
sticky bit set.  Then, setuid inside the program to whatever the effective
UID is, and everything comes up as together.  Shouldn't this ba a FAQ by
now??

Dave White

