Connections can end up in inconsistent state due to except Exception: instead of bare except:

[leifkb]

The changelog for 2.7.3 mentions all bare except:s have been changed to except Exception:. Unfortunately, this can sometimes cause connections to be released to the pool in an inconsistent state.

Here's a script that demonstrates the problem using gevent timeouts: https://gist.github.com/leifkb/5871666 And a patch: https://gist.github.com/leifkb/5871691

[andymccurdy]

The problem with the empty except causes is that they swallow KeyboardInterrupt exceptions. This means you can't kill a script that's blocked (likely in a socket call) via ctrl-c / ctrl-break. See #328 for where this change was made.

Do you know why the gevent example breaks? Is there a gevent exception that's being raised that's not inherited from the base Exception class?

[leifkb]

Yes, gevent raises Timeout, which is not derived from Exception. The code I'm suggesting changing back to bare except: re-raises the exception, so it shouldn't swallow KeyboardInterrupts. And I think having it not catch KeyboardInterrupt is buggy too -- if a KeyboardInterrupt were raised at the wrong moment, it could cause a connection to get returned to the pool in an inconsistent state too.

[andymccurdy]

Alright, I think this is correct since the exception gets re-raised anyway. Fixed in 80baa99