Hi there,

we're currently using a LVS based load balancer to manage a web cluster of 16 
realservers. We're delivering about 500GB traffic a day with about 4000 
reqs/s at peak time - and it's growing. Our main application is PHP based, 
thus we're forced to use source IP based persistence for maintaining 
sessions. Unfortunatly, this causes the servers to be out of balance often.

The idea came up to replace LVS with pound for session based persistence. The 
pound website says the largest reported volume is about 400 reqs/s.

Can someone estimate whether pound is able to handle our volume?

Thanks in advance,
Jan

On Thursday 14 October 2004 18.10, Jan Abraham wrote:[...]

In synthetic tests Pound did up to 2000 requests per second on a 4 CPU 
machine, and there is no inherent reason why it shouldn't go higher. I would 
worry more about your system limitations - I can't think of a single machine 
that could do 4000 connects per second, pretty much saturating a 100MB/sec 
link - due to both network limitations (which TCP stack can do even 4000 
connections per second, let alone the data transfer?) and CPU (though that is 
easier to solve).

At the very least you'll need to recompile your libc or libpthreads - most 
systems come with a precompiled limit of 1K threads. Not much of a problem 
but keep it in mind. I am also quite sure you'll need to do some serious 
tweaking of your network configuration and kernel.

Tell us more about your results - I'm sure quite a few people here would be 
curious.[...]