From: ken@cs.cornell.edu (Ken Birman)
Newsgroups: comp.os.research
Subject: Re: A challenge
Date: 14 Apr 92 20:15:09 GMT
Article-I.D.: darkstar.32994
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Originator: osr@ftp

In article <32869@darkstar.ucsc.edu> johnm@cory.berkeley.edu (John D. Mitchell) writes:
>Well, not to necessarily defend J. Ousterhout, you aren't giving any
>context to his statements.  My (personal) understanding of his view (having
>taken an advanced OS class from him) is that there is a lot of room for
>improvement in the way that things are done *in the 'real' world* today.
>There most certainly needs to be the off-the-wall, wacko research to try to
>figure out where things will be going to in the distant future.  There's
>also a very strong need for solid (read boring to researchers :-)
>commercially usable OS's that people can use right now.  What I think
>Ousterhout is really getting at is that there is a big gray middle-ground
>where much research can be done to bridge the gap between now and the
>future.
>
>In this vast no-man's land, there is a great need for (for won't of a
>better term) incremental (evolutionary?) improvements to today's systems.
>I'm not just talking about the next version of BSD or SVR4 but of projects
>like Plan9 and Sprite that take what has been seen in the past and trys to
>clean house a bit.  Neither of these systems are so radically different
>from either a user, programmer, or design standpoint from (dare I say)
>currently accepted systems.
>
>As you say in your post, the real world is starting to expect an awful lot
>from it's computer system.  The thing is that nobody has a solution yet.
>That why is called research.  :-)

This is a fair criticism of my remarks concerning John's points.
In fact, though, I was also a Berkeley graduate student (never took
his class), and I was present when he made this remark at SOSP.

Now, I realize that John likes to play Devil's advocate.  So, it seems
far to assume that he presented his opinion in an exagerated way.
On the other hand, he has made this same point steadily now, many times
over the past 4 years, starting with the first WWOS.  So, it also seems
likely that he really believes that there haven't been any significant
advances in operating systems "abstractions" since files, pipes, virtual
memory and processes were introduced.  At SOSP he was particularly
critical of capabilities, transactions, and group computing models.
By implication, he seemed to be critical of nearly everything done since
1975, except for the work at Berkeley, CMU and U. Washington on fast
file systems, better memory management and fast communication.

As I understood him, his point was basically that: nobody wants these
new features, they don't work, they are too complex, and that they
fail to accept that operating systems have been largely successful
doing just what they did in 1970.  Along the lines of Plan 9, he
basically called for a retrenchment of the field into these areas
of success (and away from the various wierd abstractions cited
above) and better engineering of those things that "really work"
with far less focus on innovation and new abstractions.

I think I really do understand John.  I just disagree with him, and
at SOSP I said so.  His feelings, if I recall correctly, were that
he agrees that we disagree.  He also compared the recent OS research
advances to "trying to sell pink flamingo lawn ornaments to people who
would like to buy a new car".  (My own sense is that he is trying to
sell 1970 Fords to people who would like to take a train).

Anyhow, short of hearing from John, I don't see how either you or
I can summarize his views more acurately than has already been done.

Here's one possible way to resolve this: can we agree that what John
and Henry Spencer mean by "distributed system" and what I mean by
"distributed system" are actually very different?  After all, I wouldn't
dispute John's point, if we were talking about desktop distributed
computing.  I think his point is incorrect in relation to some of the
emerging large-scale distributed systems, though, and even with
respect to some types of LAN applications in areas like CAD-CAM,
multimedia, financial systems, etc.  In fact, I would argue that his
point is right, for the type of system that a place like Berkeley runs
in house... but that Berkeley may not be typical of the world.

-- 
Kenneth P. Birman                              E-mail:  ken@cs.cornell.edu
4105 Upson Hall, Dept. of Computer Science     TEL:     607 255-9199 (office)
Cornell University Ithaca, NY 14853 (USA)      FAX:     607 255-4428