AW: Still much more than 350 sockets needed!

[Arjan van de Ven]

> Please try to open that many tcp connections between two IPs and tell me
> if it works! Finding out in which way our software opens the sockets 
> would be enough work for two persons for at least two days. It's old
> software we try to get running on a new system. Very (very very) old
> sources! ;)
> 
> Some guy told me that maybe iptables is the cause of this problem. You 
> think he's right? We have to verify that. May take a few days since the 
> collegue responsible for this isn't in the office right now. Just that 
> much about "it's urgent" (my team leader's definition). *laugh*
> 
> Thanks for your interest in this problem. I'll keep you up to date.


the number 350 rings another bell: if your software uses one thread per
connection, and uses the default stack size (which is 8 to 10Mb on
modern linux/glibc) you'll run out of 32 bit virtual address space
around 350. If that's the case you probably really want to tell the
pthreads library that you know what you are doing and that you want a
smaller stack size please ;)