What hardware do you use to run your load balancer ?
anotherjesse: I run Nginx/HAProxy/PostgresQL/Memcache/Mongrels/Solr all on a single box $200 box from serverbeach (2 cores, 3GB ram)The site averaged 581,661 dynamic requests per day over the last 21 days, and my biggest problem with the server performance has been the rails production log analyzer.  The parser hits something and spins.(I rotate my logs hourly, and this hasn't been a huge issue so I've dealt with it by watching for log analyzing processes that take too long and kill them)Sorry it isn't that exciting hardware wise.  If traffic continues to go up, I'll be needed to expand to multiple boxes, of which softlayer a nice variety and I look forward to reading more about what I should be using here.Probably stupid stats with the single box setup:  every request hits nginx, and it uses on average 3 minutes of time per day (as report reported by ps), haproxy is forwarded every dynamic request and has 4 minutes of cpu time.  I've not had to do much instrumentation of hparoxy/nginx since they are the lightest weight piece of my stack.