Maximum number established TCP connection

[Bill Moran]

In response to Matthew Seaman <m.seaman at infracaninophile.co.uk>:

> Bill Moran wrote:
> > In response to Patrick Dung <patrick_dkt at yahoo.com.hk>:
> > 
> >> Hello
> >>
> >> I would like if there is a (countable) limit for the max TCP connection
> >> of a Apache web server.
> >>
> >> Suppose:
> >> 1. An apache web server serves a very big iso file.
> >> 2. 5000 people tried to connect to the apache server to get the iso
> >> file.
> >> 3. They connect to the server gradually (not 5000 people starting at
> >> the same moment). So that there will not be a problem caused by the TCP
> >> backlog limit.
> >> 4. There will be 5000 established TCP connections.
> >>
> >> Is it true that FreeBSD could handle 'unlimited' established TCP
> >> connections as long as it has enough CPU power and memory?
> > 
> > The FreeBSD limit on the number of open TCP connections is significantly
> > higher than the Apache limit on the number of concurrent HTTP sessions.
> > I believe Apache has a hard limit of 256.
> 
> That's a compile-time option in apache-1.3.x -- you can set
> APACHE_HARD_SERVER_LIMIT in /etc/make.conf to override the default of
> 512 if required.
> 
> However in apache-2.2.x it seems the limits are imposed entirely by
> the MPM settings in httpd.conf -- at least, I cannot find any tunables
> in the port Makefiles.

Interesting.  I found this:
http://httpd.apache.org/docs/2.0/mod/mpm_common.html#serverlimit
Which claims the hard limit is 20,000.  So I guess my information is
a bit out of date.

-- 
Bill Moran
http://www.potentialtech.com