[jedberg]

I would humbly suggest that you drop ELB in favor a software based solution that you control like haproxy. ELB just isn't up to the job unless you are a really big customer of Amazon's.

Also, if you are using small or micro instances, you probably don't want to do that either. Don't use anything less than a large instance if you want even semi-decent performance.

[keikubo]

Thanks for your advice. I think chnaging load balancers to 64-bit instances is the first thing I should do. And also I heard several times about the performance of ELB, so we will change our architecture to some alternatives.