Use of select.select() in threading handler is a problem

[fried]

I ran into a situation where an application (with a ton of open FDs) was calling my application in a popen and did not use close_fd. So the single fd passed into select.select in connection.py had a int value that was too large and select.select throws a ValueError.

Using some other poller may be wise.

Take a look at asyncio.selectors.DefaultSelector for a really nice solution to different poller support on different OS's

[harlowja]

Seems like your application should be fixed right (aka to close fds)?

[fried]

One doesn't always have control of how users call your application.
But if I was actually using those fd's for other things then tried to open a kazoo client it would fail. Because the fd id number is too large for select.select, even though we only send one fd to select.