PHP is arguably the best solution here. If a log ingestion process breaks everything, no other logs are harmed (a default shared-nothing architecture). Using something like Go, C#, etc, it might be "faster" but less resilient -- or more complex to handle the resiliency.

> But for the log processor that's going to need to handle a high throughput which PHP just isn't good at.

I'm sorry, but wut? PHP is probably one of the fastest languages out there if you can ignore frameworks. It's backed by some of the most tuned C code out there and should be just about as fast as C for most tasks. The only reason it is not is due to the function call overhead -- which is by-far the slowest aspect of PHP.

> you can have Go doing thousands of requests per second vs PHP doing hundreds of requests per second.

This is mostly due to nginx and friends ... There is frankenphp (a frontend for php running in caddy which is written in go) which can easily handle 80k+ requests per second.