Would make sense to have a "addChannelClosedHandler"? about amqp

[hreinhardt]

Hi,

adding a function that's called for channel exceptions sounds like a good idea. But I'm not sure it makes sense to have another function for non-exceptional channel closes. AFAIK the only way a channel could be non-exceptionally closed is when the user calls closeChannel, in which case the user already knows the channel is about to be closed.

[adinapoli]

Sounds perfectly reasonable to me!
In case I might be able to carve some time this week and issue a PR, would you be keen on reviewing and eventually merging it?

Thanks for the blazing-fast reply ;)

[hreinhardt]

Yes, I'd review and most probably merge it.

[adinapoli]

Now that #53 has been merged, any chance for 0.12 to hit Hackage today? 😉

[hreinhardt]

Pushed it to Hackage. I initially wanted to also remove that catch in the channelReceiver but that seems to be a bit trickier than I expected.

Thank you for your contribution! Let's hope we didn't break anything.

[adinapoli]

Ha! Thank you very much! I am going to give a package a go next week, so if we did I will report back :)

[adinapoli]

As a small success story, our patch seems to work, at least superficially. This is what I get from the logs inside my development environment, when the server is running but I kill the broker abruptly:

"New job = ...
"New job = ...
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file
Rebooting the server due to 127.0.0.1:5672: Network.Connection.connectionGet: end of file

the message that you see, is triggered by this simple helper function:

-- We explicitly filter out the two cases where a channel can be closed gracefully;
-- 1. When it received a ThreadKilled exception
-- 2. When a user is shutting it down as part of the normal connection closing routine.
reactToChannelException :: SomeException -> IO ()
reactToChannelException (asyncExceptionFromException -> Just ThreadKilled) = return ()
reactToChannelException (fromException -> Just (ConnectionClosedException "closed by user")) = return ()
reactToChannelException ex = do
  yellow $ T.pack $ "Rebooting the server due to " <> show ex
  rebootServer

(I'm using the ViewPattern extension to make everything a bit more slick).
More testing is certainly needed, but this looks to me like a promising start :)