increasing TCP throughput

Hi all,

I'm using HAProxy combined with beanstalkd to create redundant queueing system. Everything is working except that I've noticed that I can queue far more messages when I push them directly to beanstalkd rather than through the HAProxy server.

There's a max of about 300 connections at any one time so i'm not sure what's causing the limit in throughput.

Here is my conf: http://friendpaste.com/4RH2zuDnuGVHEWWNlMo9k5

And my stats: http://img.skitch.com/20100225-x9mjub8tqqaffgfqw52umyiiup.png

Any help would be really appreciated!

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AJ Asver