Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!gatech!ncar!tank!uxc.cso.uiuc.edu!uxc.cso.uiuc.edu!m.cs.uiuc.edu!gillies
From: gillies@m.cs.uiuc.edu
Newsgroups: comp.sys.next
Subject: Re: What's coming?
Message-ID: <61300008@m.cs.uiuc.edu>
Date: 27 Jun 89 02:13:00 GMT
References: <65100001@tippy>
Lines: 27
Nf-ID: #R:tippy:65100001:m.cs.uiuc.edu:61300008:000:1182
Nf-From: m.cs.uiuc.edu!gillies    Jun 26 21:13:00 1989


/* Written  5:41 am  Jun 20, 1989 by owen@eedsp.gatech.edu in m.cs.uiuc.edu:comp.sys.next */
> What happens when you try to distribute a very successful package that
> sells many thousand copies? I can just see the 30 or 40 thousand people 
> that got TurboC upgrades when 2.0 came out try and download it at the
> same time.

Actually, this is a problem that can be attacked with queueing
theoretic-assumptions, and a system of PCs configured to handle the
predicted loads.  Remember, we've solved this old problem rather well:

"How can we give everyone a telephone?  Won't they all want to make a
phone call at once?"

There are many games you can play, such as mailing out the upgrade
invitations gradually, and making some gaussian-distribution
assumptions about when people will call during the day and night.  You
can also redirect people to call back at a scheduled time, if they
call during an overloaded period.

Overload is only a problem if you let it scare you, or if you don't
plan ahead.....


Don Gillies, Dept. of Computer Science, University of Illinois
1304 W. Springfield, Urbana, Ill 61801      
ARPA: gillies@cs.uiuc.edu   UUCP: {uunet,harvard}!uiucdcs!gillies