Dear Russell,
Thanks for your input. The limiting factor for my redhat linux 2.2.5
installation was a per user process limit of 256. The reason I
sometimes got 256 or 257 concurrency is that reporting is not exactly
synchronous with forking.
Thus, in addition to increasing the number of file handles, you need to
rebuild the kernel after editing:
/usr/src/linux/include/linux/tasks.h NR_TASKS from 512 to e.g. 2048.
Per-user limit defined to half this on the line below.
There also appears to be a bug that limits the number of per process
file handles to 1024. There are "unofficial" patches for this, but
AFAIK, not integrated into the official kernel.
If anyone has more insight into this, I'd love to hear it. With the
patch, our P100/64MB does very well at a concurrencyremote of 400.
Since performance was limited by concurrency (many slow/dead clients)
we got considerably better throughput.
-Sincerely, Fred
(Frederik Lindberg, Infectious Diseases, WashU, St. Louis, MO, USA)
