what is the limit on number of concurrent Xvnc servers?

["Beerse, Corné"]

> -----Original Message-----
> From: Mike Miller [mailto:mbmiller@taxa.epi.umn.edu]
> 
> On Tue, 15 Apr 2003, Jeff Boerio wrote:
> 
> > What will your users be doing?
> 
> Lots of different things.  Probably running KDE or Gnome, doing SAS
> analyses, probably not a lot of graphics.  I wouldn't expect everyone to
> be on at the same time, so they should be swapped out much of the time (I
> assume that's how Xvnc works).

This is the best reason to use
http://www.sourcecodecorner.com/articles/vnc/linux.asp. 

> 
> 
> > From my experience, you'll run into hardware limitations before you'll
> > run out of available ports on the machine.
> 
> My eight users seem to be doing fine on 640 MB, so I'm thinking that with
> 8192 MB, I can support more than 100 Xvnc users.

I think the major limitation is also the network connection. Once you run
into problems with multiple concurent users, best to start looking at
network trafic and processor usage. If there is bandwidth left but no cpu
power, go for raw encoding. If there is no bandwidth left but there is still
cpu power, force some encoding.

To be usable, I'd say 600*800 with 8 bits colors is acceptable at all sides.

> 
> 
> > We have 2gb and 4gb machines available, but with heavy interactive usage
> > (and with large applications), it makes little sense to allow more than
> > 10 people to concurrently have active VNC sessions.
> 
> It may make more sense to stop them, but how do you stop them?  Maybe I
> don't understand what you mean by 'active'.  It seems to me that if the
> Xvnc processes are running, I don't have a way to stop users from making
> those processes active and using memory.  If, on the other hand, by
> 'active' you just mean that the Xvnc process is running, I guess there
> might be a way to stop people.  Still, I'd rather let them go at it and
> see what happens.

The 'stop them' is done by inetd (or xinetd) with the setup as on
http://www.sourcecodecorner.com/articles/vnc/linux.asp.

> 
> 
> > If you're expecting users to be able to use graphics-intensive or
> > CPU-intensive applications, web browsers, etc, then you'll not want to
> > use this approach.  If everyone's running nothing but xterms all day
> > long, maybe you can do it.
> 
> It isn't clear to me what they might do.  I don't expect much graphics and
> probably no web browsers.  Mostly xterms, plus overhead from KDE or Gnome.

This overhead of gnome and kde can ruin your day. Best to configure it to
move borders only, no fancy slow appearing and sliding windows and such.
Also don't accept background images and such, best to put it in one color.

> 
> I'm getting the impression that maybe 99 is my real limit on Xvnc servers
> running concurrently.  And that was my original question.  Is 99 the
> limit?

It's a limit but there is an other limit at :63



CBee