May be I got it the wrong. Are the time spent on the bid processing portion (CPU bounded) or the network messaging and connection handling portion (IO bounded)? When talking about eventlib and nginx, I assume the network messaging and connection handling are relevant. In that case 168K requests/sec doesn't sound too great.

This benchmark shows Ngix+Lua (openresty) is more than 5 times slower than the leading ones, which can do more than 6M requests/sec.

https://www.techempower.com/benchmarks/#section=data-r11&hw=...