Automatic heartbeating for WebSocket and WAMP-over-WebSocket



Autobahn>Python and (both trunk, will be in next releases) now implement automatic WebSocket heartbeating ("WebSocket ping/pong").

This is useful in two ways:

* fast detection of lost connections (network connection failures and such)
* keeping mobile connections in a fast/low-latency state

There are 3 knobs to control this stuff:


Of course there is a tradeoff: doing ping/pong at a higher frequency means broken connections are detected faster, but it'll also mean more wire level traffic.

No free lunch - as always.



Note: We might still want ping/pong at WAMP level, independent of WebSocket, since WAMP can run over non-WebSocket transports as well.

But above should cover a lot of practical use cases already.