I'm using a LEMP stack, with separate php5-fpm pools for two wp pages. Both nginx and php5-fpm pool config files are identical except for site and the socket names. I do static pools with 2 workers each.
The observed phenomena are the following:
- If I have only one site active, it is super quick to load <<1s response.
- If I have two sites active, the first site response goes to 1s and the second >10s - often hitting 504 timeout.
- If I don't use different pools for the different sites then both slow down to 2-10s waiting time for response.
- The slowdown only happens on the php requests, the static file requests are unaffected.
- Similar phenomenon happened when I tried LAMP stack.
What is going wrong here? Where could be the problem? How could I track this one down? I could not figure out what logging/debug/stats options I have... :(
Edit:
This is development phase, very low traffic website, so the issue cannot be that I'm running out of workers. I have a single request coming in.