Path: utzoo!news-server.csri.toronto.edu!rutgers!usc!snorkelwacker.mit.edu!bloom-beacon!dont-send-mail-to-path-lines
From: mouse@lightning.mcrcim.mcgill.EDU (der Mouse)
Newsgroups: comp.windows.x
Subject: Re:  MAX_CLIENTS limit
Message-ID: <9103090405.AA24637@lightning.McRCIM.McGill.EDU>
Date: 9 Mar 91 04:05:53 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 34

> Can anyone tell me where the maximum number of clients allowed is
> defined?

As someone else already noted, it's the server that's doing this (as
would have to be the case); in the case of the MIT server, it does a
getdtablesize() when it starts up and starts refusing new clients when
it's within one or two of running out.

> I currently have 18 (on a Sun 3/50 - os4.1 12Mb X11R4 twm) and on
> trying to open number 19 this happens:

The *server* is running under 4.1?  Something weird is wrong then; 4.1
by default has the descriptor limit set to 64, I believe.  You should
be able to connect about 55 clients before it starts losing.  Your
symptom looks more like what I'd expect from a server running under
release 3.5.

As to what can be done about it, besides switching to an OS that allows
more file descriptors per process....

I hacked on the server so that it can fork a multiplexor subprocess to
alleviate this problem.  This raises the effective maximum to about 30.
I could make it do multiple multiplexors, but have never felt any need;
I've never run out of clients since.

I do not have these changes in the form of distributable diffs.  If you
want to take your chances with the raw code, they should be available
for ftp from 132.206.1.1, in X/myX/X11R4/server/os/4.2bsd/ (you want to
look at the MUX_CONN compile-time option.)

					der Mouse

			old: mcgill-vision!mouse
			new: mouse@larry.mcrcim.mcgill.edu