Client hangs forever if the daemon crashes

[ppalaga]

The daemon may crash for whatever reason, even without calling shutdown hooks. There should be a way for the client to find out that the daemon is down (so that client itself can exit).

[famod]

Just a quick thought: The daemon could touch a file periodically and the client could check if the file was touched recently. If not the daemon most likely crashed.

[gnodet]

Given we have a socket connection, we could simply send a simple keep-alive message from the daemon to the client every second (if nothing has been sent). On the client side, if we haven't received anything since 3 seconds, we consider the daemon crashed.
That's really the same, but it reuses the current socket channel which is already opened.

[ppalaga]

we could simply send a simple keep-alive message

Yeah, I also thought of that