Socket problem in Fedora Core 2

[Bob Chiodini]

On Thu, 2005-09-08 at 10:10 -0400, Bob Chiodini wrote:
> On Thu, 2005-09-08 at 14:58 +0200, Andreas Storm wrote:
> > Hi,
> > 
> > My setup: Fedora Core 2 with 2.6.10-1.771_FC2smp kernel.
> > 
> > I'm currently developing a simulator for load testing
> > which needs to handle around 40-50K connections. A mixture of TCP and UDP.
> > 
> > I changed the amount of file descriptors to 64000
> > with ulimit -n 64000 as root.
> > 
> > But when I run and reach around 27000 TCP connections
> > my application stops and dmesg writes the following:
> > 
> > "out of socket memory" several times.
> > 
> > I wonder what is the problem and how it can be fixed. Didn't have any luck at the mail archive or google.
> > 
> > Any help appreciated.
> > 
> > Br,
> > /Andreas
> > 
> > 
> > 
> 
> Andreas,
> 
> I found the "out of socket memory" in tcp_timer.c.  The implication that
> the sysctl variable net.ipv4.tcp_max_orphans controls the limit (among
> other things).  On FC3 this is set to 65536.  What is it in FC2?
> 
> Bob...
> 

Andreas,

I found an FC2 machine:

/sbin/sysctl net.ipv4.tcp_max_orphans
net.ipv4.tcp_max_orphans = 16384

You might try bumping that number up.

Bob...