Poor web serving performance

[Cal Henderson]

Brad Fitzpatrick <brad at danga.com> wrote:
: Sure doesn't look like it's working!  Unless it's using NPTL?  What
: arch/kernel you using?

[calh at pc12 Perlbal-1.53]$ cat /etc/redhat-release
Red Hat Enterprise Linux AS release 4 (Nahant Update 2)

[calh at pc12 Perlbal-1.53]$ uname -a
Linux pc12.xxxxxxx.com 2.6.9-22.ELsmp #1 SMP Mon Sep 19 18:32:14 EDT 
2005 i686 i686 i386 GNU/Linux

[calh at pc12 Perlbal-1.53]$ perl -V | grep archname
    osname=linux, osvers=linux, archname=i686-linux-64int

[calh at pc12 Perlbal-1.53]$ getconf GNU_LIBPTHREAD_VERSION
NPTL 2.3.4


so it /is/ using NPTL threads. if i switch to linuxthreads:

[calh at pc12 Perlbal-1.53]$ export LD_ASSUME_KERNEL=2.4.19
[calh at pc12 Perlbal-1.53]$ getconf GNU_LIBPTHREAD_VERSION
linuxthreads-0.10

then i can see the additional processes spawning. however, on startup, 
i only see 2 processes:

[calh at pc12 Perlbal-1.53]$ pstree -aclp | grep perlbal
  |                   --perl,25351 ./perlbal --config=my.conf
  |                       --perl,25352 ./perlbal --config=my.conf

and then when i throw some load at it, more processes get created:

[calh at pc12 Perlbal-1.53]$ pstree -aclp | grep perlbal
  |                   --perl,25351 ./perlbal --config=my.conf
  |                       --perl,25352 ./perlbal --config=my.conf
  |                       --perl,25362 ./perlbal --config=my.conf
  |                           --perl,25363 ./perlbal --config=my.conf
  |                           --perl,25364 ./perlbal --config=my.conf
  |                           --perl,25365 ./perlbal --config=my.conf
  |                           --perl,25366 ./perlbal --config=my.conf

but never the amount i specified using SERVER aio_threads = 40 (and i 
don't get better performance).

any ideas?


thanks,

--cal