[79] in installers
Re: Eudora 3.0.2 installer
daemon@ATHENA.MIT.EDU (Paul B. Hill)
Wed May 14 09:21:25 1997
Date: Tue, 13 May 1997 23:51:59 -0400
To: Alicia Allen <iggy@MIT.EDU>, installers@MIT.EDU
From: "Paul B. Hill" <pbh@MIT.EDU>
Cc: pgalt@MIT.EDU, iggy@MIT.EDU
In-Reply-To: <v0302090aaf9d80caea06@[18.162.0.49]>
>The only part I'm not understanding here, is that 7 people installing the
>software at once is too many?
I've tried to look into this a little bit further. If too many connections
are initiated at the same time the inted process will shut down, and wait a
while before it restarts. This is protection code because this looks the
same as an attack on the system.
Starting these only a few seconds apart should be enough to avoid this
problem.
Some thought has to be given to this. Remember the installer does not
initiate a connection to the server. This happens later during the
execution of the installer. Having a class start the installer at a
seperate time will not eliminate this problem. Having them click on the
button that actually starts the ftp process about 10 seconds apart should
help to avoid the problem.
It gets more complicated.
If you run the installer off a centralized file server, cache issues may
cause the clients to synchronize, again causing the problem. Additionally
some installers initiate multiple connections, various factors may also
cause installers started a few seconds apart to synchronize at a later
point during the installation process.
Try initiating the portion of the installer that initiates the connection
about 30 seconds apart.
>...However,
>when we tried to have just one person install the software, that wasn't
>possible either.
Was this just a short time after experiencing the problem with multiple
people running the installer at the same time? Note what I said about inetd
shutting down for a short time above.
>Since I have never had net-dist tell me that there were
>too many people doing anonymous ftp at once, I'm confused.
You're lucky :) We limit net-dist to 30 simultaneous anonymous MIT users at
one time and 30 simultaneous anonymous users fro outside the MIT domain.
There are times when the server gets too many connections. Usually because
of bad ftp clients that keep an idle connection open.
>Does net-dist
>have really that high of a load?
At the moment net-dist is doing multiple duty. This will be changed in the
future. The change may also help the classroom situation slightly.
>Or did we happen to run into a very busy
>time?
It's possible I don't have enough information to determine that.
>We had no problem with 7 people downloading the installer
>at the exact same time, and that was also anonymous ftp to net-dist.
>
Was it possible that the installer was in a browser cache?
Paul
