[JDEV] Stress testing and connection limits

[Chuck Bohling]

I've been stress testing Jabber to get a feel for how many concurrent users
it can handle. I've hit some limit on the number of connections that Jabber
will accept. Hopefully, it's a soft limit in Linux or Jabber, or maybe a
mistake in my test. (Could it be a problem with Windows 2000?) Here's what
I've done. The test is in C++ on Windows 2000. The program spawns some
number of threads, emulating Jabber clients. Each "client" starts a stream,
registers, authenticates, does an online presence, and then, in a somewhat
random fashion, sends messages to other "clients". The receiving client
prints the message. This works great up to about 1000 (1024?) clients
(threads). Above that number, I start seeing all kinds of failures. I think
it may be caused by pth_accept rejecting the connection, but I'm not sure.
Anyone have any ideas? I did disable the connection rate check in tlisten.c.
Hopefully, it's something like a 1024 limit on the number of connections
from the same IP.

Thanks
Chuck Bohling