How can I have multiple asyncio processes listening on the same port? about asyncio

[1st1]

I am aware the correct way to approach this situation is wsgi, which is where we're headed. However I'm curious if it's possible directly.

I don't think anything async should ever use WSGI stack. So it's something you can try, but it's definitely not "the correct" way.

I know that Sanic uses uvloop by default, so my question is: have you tried both asyncio and asyncio+uvloop with reuse_port=True?

Also, there are other ways how you can share a socket between multiple processes. One way is to manually create a socket in the main process, bind it, set it to be inheritable, and then fork (either manually, or using multiprocessing). Then, in subprocesses, you can start asyncio event loop and call loop.create_server(sock=inherited_sock).

[r0fls]

I am aware the correct way to approach this situation is wsgi, which is where we're headed. However I'm curious if it's possible directly.

[gvanrossum]

Note: I've never heard of Sanic and haven't looked at its code. But maybe this comment from the referenced thread is relevant?

I wonder if the issue is that different process can't share same uvloop.

How does Sanic create worker processes? If it just forks and then runs the same code in each, especially if the loop has already been started, that is indeed a problem. Is there a way create the workers first and then create a loop in each one?

[r0fls]

If it just forks and then runs the same code in each, especially if the loop has already been started, that is indeed a problem. Is there a way create the workers first and then create a loop in each one?

This does look like what is happening...

have you tried both asyncio and asyncio+uvloop with reuse_port=True

Yes, I've tried removing uvloop and using only asyncio, which is why I opened the issue here.

[r0fls]

I got this working with the method suggested by @1st1, thank you both.