While I’m not sure this is the correct place to post this, I said I’d give it a try, maybe there’s someone who can help:
We’re given the following scenario: an ubuntu 20.04 (kernel 5.4.0-146-generic) with a fairly loaded HAProxy - 2.6.12-1ppa1~focal 2023/04/01 (140k max sessions with a 10k session rate - HTTPS traffic). With this setup, the CPU usage is around 80%, while eating up ~700Mbps in bandwidth.
After updating the machine to Ubuntu 22.04, the exact same setup, with the exact same traffic pattern has a lower max sessions, a lower session rate, a lower bandwidth usage and a higher CPU usage. What’s going on?
I don’t even know how to start debugging this, as the only thing running on this machine is the HAProxy.
Any help will be greatly appreciated.