re: > 15K simultaneous connections EXAMPLE program/OS config needed,

Dan Kegel (dank@alumni.caltech.edu)
Thu, 16 Sep 1999 22:54:45 -0700


"Stephen D. Williams" <sdw@lig.net> asked:
> Stephen, or anyone else, are you aware of a test program that illustrates the
> use of existing (2.2.12+) mechanisms to efficiently handle many sockets?

There are a couple programs like that listed at
http://www.kegel.com/c10k.html

> Is there a limit to the number of connections per IP address, assuming many
> different client IP's? (In other words, is there any problem with running out
> of local sockets? There shouldn't be really since a client program that
> doesn't specify a certain local socket doesn't care if it has that same socket
> number used with N different remote IP's.)
>
> I really want to handle 100,000 TCP connections simultaneously per system,
> eventually.

Guess I should rename my page c100k.html :-)

Alan recently said that each handle takes up 20k in kernel space.
so 100,000 connections could take up 100k*20k = 2GB of RAM,
which might cause some trouble except on very recent kernels
(and maybe you still need a patch for this).

I'd be interested in hearing whether anyone has gone past
64k handles opened; who knows, maybe some bad code somewhere is
using a short to hold an fd.

- Dan

-- 
(The above is my opinion alone, and not that of my employer)

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/