Clarify granian not ideal for gevent - explain like I'm five

[lukasz-leszczuk-airspace-intelligence]

Hey,
I'm looking into replacing gunicorn in our application stack (django rest framework and fastapi services) and granian generally seem like a good fit, but documentation mention potential issue with gevent.
Can you please clarify what it means? For the context, I'm an infrastructure engineer, not SW developer, and I'm not too familiar with gevent internals. I know some of our applications use gevent - to various extent - and I wonder if granian + gevent require just some additional configuration tuning or certain features are completely broken?

[gi0baro]

I'd say it's probably the latter: if I'm not mistaken gevent would require the single request to be processed in a greenlet, but in Granian there's no ready-to-go handler that support spawning those.
The WSGI implementation uses a standard threadpool, so even if you had a non-blocking operation going on, Granian won't be able to detect that and keep waiting for that thread to finish and return the response.

At the time, there are no plans to effectively support this, mainly for the different priorities the project has and for the lack of knowledge I have in using/developing with gevent.