Killer Micro Question

[Eugene N. Miya]

In article <16364 at s.ms.uky.edu> randy at ms.uky.edu (Randy Appleton) writes:
TOO MANY NEWS GROUPS....
>I have been wondering how hard it would be to set up several 
>of the new fast workstations as one big Mainframe.

Physically: not very hard, these days.  Software will be your problem.
You must be an aspiring hardware type 8^).  You would have to totally
rewrite many existing applications, a few from scratch.  You are
making the assumption that the sum of workstations == a mainframe.
This may not be the case.  [Gestalt: the whole is great than the sum of
the parts.]  Perhaps adding computation late in the
game will only make the computation slower (later).  This will depend
very much on the nature of the application: language, algorithm,
communication cost, etc.  Seek and yea shall find some hypercubes.

>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.

>some such thing), so as to presurve the illusion that this is one big
					 ^^^^^^^^ sometimes a dangerous word.

>What would be nice ....
>The idea is that as each person logs into the Login Server, their login 
>shell is acually a process that looks for the least loaded Server, and 
>rlogin's them to there.  This should distribute the load evenly 
>(well, semi-evenly) on all the servers.
.....
>you got (which ought to be invisible) you saw the same files.
			    ^^^^^^^^^ [aka transparent]
This is a dream which as existed since the 1960s with the ARPAnet.
It has seen limited implementation.  There are many subtle problems,
but it interests a lot of people: load oscillation effects,
reliability, error handling, etc.  Performance gains are needed to
solve future problems.

>So my questions is, do you think this would work?  How well do you
>think this would work?  Do you think the network delays would be excessive?

Network delays are probably the least of your problems.  Again, it will
for for limited applications.  The problem is basically a software
problem.  If you don't have it, it won't work.  Depends on your basic
building blocks (some of OUR applications require 128-bit
floating-point).  I have an officemate who is absolutely fed up
debugging distributed applications (graphics).

  Neil W. Rickert writes:

| Suppose you wanted a system to manage huge databases.
|You just might find the mainframes a better solution than the workstations.
|
| IBM didn't get that big by ignoring its customers' needs and forcing them to
|buy an excessively expensive and underperforming system.  Instead they
|carefully
|monitored those needs, and evolved their hardware and software to meet them.

Sure, for some DBMS applications (and systems), but you must be posting
from an IBM system 8^).  Many workstations are not excessively
expensive, and quite a few are very fast, even faster than mainframes.
But, please, if you wish, stick with dinodaurs.

--e. nobuo miya, NASA Ames Research Center, eugene at orville.nas.nasa.gov
  The Other Eugene.
  {uunet,mailrus,other gateways}!ames!eugene