HA-Proxy conn/sec

Hi ,

I had a query regarding number of conn/sec in Haproxy and with regards to it following are the details

*Setup*

Machine : Dual core AMD Opteron(tm) Processor 246 Mem:8GB
OS: Ubuntu 2.6.32-24-server x86_64 GNU/Linux

Request flow: HAProxy -> Varnish -> lighttpd ( All are running on same machine )

Haproxy is running on port 2000 , varnish on 2001 and lighty on 2002

Benchmarking tool : Httperf

Requested object is of size 43 bytes

httperf --server=x.com --uri=/x.gif --port=2000 --rate=14000 --num-conns=900000 --num-calls=1

Specifying HAproxy port for benchmarking shows max conn/sec average of 8600 ( httperf shows Errors: total 341739 client-timo 0 socket-timo 0 connrefused 0 connreset 0
Errors: fd-unavail 341739 addrunavail 0 ftab-full 0 other 0 ) whereas specifying varnish and lighty ports show average conn/sec very close to 14k with no such errors.

Is this problem with HAproxy setting ? How can the conn/sec for HAproxy be bumped up to what varnish/lighty achieved in test results .

Following is the HA-proxy config
global

       log 127.0.0.1   local0
       log 127.0.0.1   local1 notice
       maxconn 32768
       ulimit-n 131072


       #debug

       #quiet

       user haproxy
       group haproxy

defaults
       log     global
       mode    http
       option  httplog
       option  dontlognull
       retries 3
       fullconn 400000
       maxconn  200000
       contimeout      10000
       clitimeout      50000
       srvtimeout      50000

listen webfarm *:2000

      mode http
      stats enable
      balance source
      acl test_domain hdr(host) test.my.net

use_backend test_server if test_domain
default_backend test_server

backend test_server

      mode http
      balance roundrobin
      option httpclose
      server varnish 10.1.0.1:2001 minconn 300 maxconn 14000
      option redispatch
      contimeout 10000