Are there good articles on the benefits of async over something like PHP-FPM?
At $WORK, we run a lot of 1000s of php servers with 10-20 processes each using nginx. External calls we don’t need the result of immediately get kicked out to an external queue, but we haven’t seen any issues with DB calls blocking the whole server.
Long or slow DB connections are an issue for individual request time and DB load though (the biggest DBs we run handle 1000-2000 concurrent connections).
I think one of the forgotten blessings of PHP/CGI was that requests had to finish sometime so as to free the PHP process for the next request. This alone I feel ended up making decisions easy around when it felt right to offload stuff when slow requests started to affect index.php from rendering in a timely fashion but now that's often masked (rightly) by caches and other tricks.
Right now in a microservice model often you have to remind developers that it just isn't ok to have a ~1ms response in a basic case and a 1 second to infinitely blocking case during errors or slow remote services.
At $WORK, we run a lot of 1000s of php servers with 10-20 processes each using nginx. External calls we don’t need the result of immediately get kicked out to an external queue, but we haven’t seen any issues with DB calls blocking the whole server.
Long or slow DB connections are an issue for individual request time and DB load though (the biggest DBs we run handle 1000-2000 concurrent connections).