Re: A challenge

[yodaiken@chelm.cs.umass.edu (victor yodaiken)]

In article <32507@darkstar.ucsc.edu> ast@cs.vu.nl (Andy Tanenbaum) writes:
>
>Gee, reading this newsgroup is more fun than whacking a hornet's nest with
>a baseball bat.
>
>I am quite unconvinced.  While I could go after each of the comments posted
>here in the past couple of days, I will resist the temptation.  Instead,
>for the second act, I hereby challenge all the people who have commented
>on my list to do better.  List what YOU consider the five most important things
>we have learned about distributed operating systems in the past 20 years.

Here's four. Two are negative, but that's the breaks.

1. The "fast, clean, communication system" as a foundation for
constructing a distributed o.s. is a mythical object. Distributed o.s's
require different communication mechanisms for different purposes and there
is no single abstraction which can be used as a building block for all others
without a significant cost in performance and ease of use.

2. The UNIX "everything is a file" paradigm extends to networks pretty
well.

3. It is possible to perform significant, on line, "compilation" of
multi-layered o.s. code. The use of this method by Massalin, seems to me to
be one of the most significant advances in the state of the art in
recent years.

4. Current system design methodologies are serious impediments to advance.
Our inability to quickly prototype ideas, to concisely describe (in detail)
the workings of distributed algorithms, and to perform any kind of
verification of algorithms short of testing make o.s. research overly 
tedious. 
 

-- 


yodaiken@chelm.cs.umass.edu