John Neffenger wrote:
> I removed that page since I think it's obsolete. Fortunately, I haven't
> had to go recompile the Kernel or the Glibc library in years.

Yeah, it was getting old, and having it around was confusing.

Now that machines are getting so fast, maybe it's worth
running Volanomark up beyond 6000 clients
( that's where http://www.volano.com/report/network.txt stops
at the moment ). To do so, you might well need to recompile
the Linux kernel to pick CONFIG_3GB. So maybe an updated
version of that page is called for after all.

Looking at the Volanomark page, I see that Blackdown wasn't
tested with native threads. Maybe it's time to try that,
since the world seems to be moving in that direction.

Has anyone gotten Volanomark results for the just-released
Blackdown JVM yet?

> Using the following options with Blackdown 1.3.1-02b-FCS on Red Hat
> Linux 8.0, I got 10,000 active socket connections (with 20,000 threads)
> on a 500-MHz Intel Pentium III with 384 megabytes of RAM:
>
> /usr/local/j2sdk1.3.1/bin/java -green -Xmx256m -Xss64k ...

Note to readers: he's using a smaller thread stack than the
previous poster (64k vs. 100k). At 1GB address space limit
(or 2^30 bytes), that's an upper limit of 2^(30-16 = 14) = 16000
or so threads.

> All I had to do was increase the per-process file descriptor limits for
> all the socket connections, by doing the following.
>
> Add to /etc/pam.d/login:
>
> session required /lib/security/pam_limits.so
>
> Add to /etc/security/limits.conf:
>
> * soft nofile 1024
> * hard nofile 10240
>
> Don't forget to add a "ulimit -n 10240" to your startup script.

Note that the above only affects future login sessions,
so you'd need to log out and log back in.

Alternately, you can become root, and temporarily raise the limit:
$ su
# ulimit -n 10240
# su dank
$ java ...
Handy if you're not sure you want to edit limits.conf just yet.

- Dan

--
Dan Kegel
http://www.kegel.com
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045