Large Un*x Applications ?

[william.clare.stewart]

In article <35490001 at hpcmsrb.HP.COM> coletta at hpcmsrb.HP.COM (Mary Coletta) writes:
} I was curious to the usage of Un*x in the realm of Business Applications.
} There appears to be consensus that Un*x does not support Business 
} Applications primarily because it can not handle a large number of
} simultaneous users.  A large number of users would be greater than 100
} people at a time.  Response time that is expected, would be less than
} 5 seconds for normal transactions (database update, addition, etc).

The basic problems aren't UNIX itself:
	- UNIX used to only run on smaller machines
	- people who built software for the mainframe environment
		wrote code that only ran on  IBMish systems, so when
		UNIX started to become available on big machines,
		they already had billions and billions of lines of
		non-portable COBOL that they liked.
	- The terminal handling environment on  traditional IBM
		mainframes was very unfriendly, but it moved a lot
		of work off the CPU into terminals and cluster
		controllers, making CPU use efficient.
		Most UNIX applications are designed for friendly,
		CPU-intensive interaction,  which doesn't always
		scale well (like vi or emacs), or are based on the
		older paper-TTY terminals (ed is very efficient, if
		not "user-friendly".)  Neither are required.

I've been on Amdahl mainframes with  several  hundred people doing
generic software development, mail-reading, troff, etc.  performance
is fine.  The  largest number of users on *any* machine that I've heard 
of is  >1000 people on the AT&T 3B4000 machines used for the  French
Teletex applications (these are exceptional - all the users have
their little 300-baud terminals typing in  cooked-mode, so almost
everything is done by the I/O boards without  even  bothering the CPU,
and the work fits very well into the  3B4000's non-shared-memory
multiprocessing model.)

You can do realistic traditional business applications just fine on
UNIX on  mainframes, or even  on  your HP 850's :-).   You have to
look  at  the amount and complexity of terminal I/O,
the number and complexity of DBMS transactions, etc. - a mainframe
is fine for  fill-in-the-blamks on 3270s, but if you want instant
verification  and response to every keystroke it just won't cut it.

} 8)  Where do you work, and what's your position?
AT&T Bell Labs, Government Systems Integration  Department, or some
title about like that.  We look at a lot of government bids on large
messy jobs.

-- 
# Bill Stewart, AT&T Bell Labs 2G218 Holmdel NJ 201-949-0705 ho95c.att.com!wcs
# "If it weren't for us, American troops would be invading exotic places like
# Lebanon and Grenada, and the Air Force would do stuff like bombing Libya"
#		Abbie Hoffman, R.I.P