benedekh
commented
7 years ago tl;dr: a 'simple but brutal' System.exit(0) would be fine.
Good question, I had the same issue with the KVServer. I'll have a look how we handle the graceful quit (e.g. closing the ongoing connections, closing the ServerSocket also).
longer explanation:
Ah it is not properly handled on the KVServer either. It should be something like this:
Basically the trick is: weloveclouds.commons.networking.IConnectionHandler extends ICallbackRegister which can register a callback (Runnable). SimpleConnectionHandler implements that interface, and in its run() method's finally section, it runs every time callbacks if there is anyone registered there. So as soon as the respective SimpleConnectionHandler handles that request which initiated the ServerShutdown call, shuts down the server. Since every Socket and Connection is encapsulated in a try-with-resources block their close method will be called automatically.
Aaand that's why it is not handled this way on the KVServer's quit client command. So the simple System.exit(0) will do the trick. -> And now I know why it was necessarry to implement the ICallback. :-) It is due to the fact that ECS expects for a response (SUCCESS) from the KVServer to make sure it received the shutdown request. So that response has to be sent back before the server would shut down. And that's why we need that ICallbackRegister. :-)
ghost
banctilrobitaille
I'm unsure of how to handle quitting properly, should I attempt to shut down the service and then quit or just quit straight away?