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On Fri, 7 Mar 2003 10:08:01 -0500, Rocco Caputo <[EMAIL PROTECTED]> wrote:

> On Thu, Mar 06, 2003 at 11:00:28AM -0600, [EMAIL PROTECTED] wrote:
> > Didn't see it in the docs, if it is please point me to it and I will
> > look harder next time :-)...
> > 
> > Is there a known and predictable limit to the number of sessions
> > that can be created/run?  Obviously there is the physical memory
> > boundaries for the hardware, and there are limits on Perl's scalar
> > size, etc. depending on architecture, but other than similar such
> > reasons, is there anything specific in the POE kernel/session
> > preventing it from having an arbitrary number of sessions?
> 
> No, POE will let you try to spawn as many sessions as you want.  The
> operating system will eventually get in your way with petty concerns
> like memory limits, open file limits, or process limits.
> 

Dang OSes always getting in the way. Luckily by the time we scale to that point I 
think the company would be ok with throwing more money at it to throw more hardware at 
it :-).

> > I am not terribly concerned, but am just curious about the system in
> > general as I think it rocks and I am enjoying developing a new app
> > in it.  The app watches directories and queues files to be processed
> > in multiple stages (each a queue), etc. As our app scales the number
> > of directories being watched (each as a session) and the threshold
> > of the process queues (number of simultaneous processes allowed for
> > each queue, each a session) can be set by the app admin, so I need
> > to know if I am going to hit a spill over point and would need to
> > restrict the threshold on the queues, etc.
> 
> If your ulimit for simultaneous processes is high (or unlimited), you
> may want to keep them within reasonable limits yourself.  POE will not
> hesitate to "forkbomb" your machine if you ask it to.
> 

Yeh, I figured on that, which hopefully the people (always the weak point ;-)) running 
the app will keep it from causing this, which is reasonable for us as this is really 
an inhouse only setup.

> If you'd like to experiment with POE's session limitations, take a
> look at the samples/forkbomb.perl that comes in POE's tarball.  It's
> not a real fork bomb because it doesn't call fork().  Instead it
> spawns sessions that spawn other sessions.  To see how far you can go,
> increase $max_sessions or remove the checks for it entirely.
> 

Thanks, if the concerns come up from anyone else I will have this tool in my back 
pocket for testing.

http://danconia.org

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