Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!dianne.usc.edu!blarson
From: blarson@dianne.usc.edu (bob larson)
Newsgroups: comp.os.misc
Subject: Re: Test for distributedness
Keywords: distributed system sprite process migration
Message-ID: <23698@usc.edu>
Date: 26 Mar 90 05:39:55 GMT
References: <6117@star.cs.vu.nl> <6067@star.cs.vu.nl> <2604@quiche.cs.mcgill.ca> <6106@star.cs.vu.nl> <6548@becker.UUCP> <9003260052.AA262747@sprite.Berkeley.EDU>
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In article <9003260052.AA262747@sprite.Berkeley.EDU> douglis@ALLSPICE.BERKELEY.EDU (Fred Douglis) writes:
>Sprite would not pass Andy's test for distributedness, though it, too,
>would come close.
[...]
>For example, what if someone from sprite
>wanted to rlogin to a unix machine?  If rlogin just claimed to be from
>a single internet address "sprite.Berkeley.EDU", then all packets
>would have to be routed via that machine, even though my own
>workstation is capable of running IP/TCP and communicating directly.

Couldn't the sprite network be configured to look like a single machine
with multiple network interfaces on the same network?  Although unusual,
I think this would be legal.  Would redirects be sufficient to allow
packets to be sent to the host that (currently) wants them?

>With respect to load sharing, we provide transparent remote execution
>(users on one host can run "pmake" and other programs to use multiple
>hosts in parallel) but we also provide performance guarantees to the
>owner of a workstation.

Tops-20 also had a way to guarentee performance to users, so a minimum
guarentee of performance realy isn't a way to distinguish a distributed
system from a single processor one.  (I think this was normally used
for groups, but a group could consist of a single users.)  What's the
difference between a guarantee of 10% of a 10 mip machine to that of
100% of a 1 mip machine?
Bob Larson (blars)	blarson@usc.edu			usc!blarson
I do enjoy receiving money.  -- Richard Stallman
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