It was my first test since I moved house. I wanted to quickly plug the machines together to see if my work on version 1.4 went into the right direction, and most importantly was not causing performance drops. Verdict below confirms it. A new record of 108000 HTTP requests processed per second was broken, and a new record of 40000 forwarded HTTP requests per second was broken too.
The first test only accepts a new connection, reads the request, parses it, checks an ACL, sends a redirect and closes. A session rate of 132000 connections per second could even be measured in pure TCP mode, but this is not very useful :
The second test forwards the request to a real server instead, and fetches a 64-byte object :
These improvements are due to the ability to tell the system to merge some carefully chosen TCP packets at critical phases of the session. This results in lower number of packets per session, which in turn saves both bandwidth and CPU cycles. The smallest session is now down to 5-6 packets on each side, down from 9 initially.