Re: [hybi] NAT reset recovery? Was: Extensibility mechanisms?

[Pieter Hintjens <[e-mail]>]

On Mon, Apr 19, 2010 at 10:54 PM,  <[e-mail]> wrote:

> Hmm... Even if the protocol as a whole is asynchronous (both ends can generate frames at any time), isn't it still possible to exchange requests and responses as well over the same transport connection?

Here is the logic we used when designing AMQP's KA mechanism.

Let's say we use a req-resp model over a symmetric async connection...

* if the other party is sending us stuff, KA responses are redundant
* If we're sending stuff, KA requests are redundant
* Since we're symmetric, both peers would send requests when idle
* Thus a response is always redundant

And it boils down to sending NOOPs when otherwise idle, to ensure the
other party knows we're still alive (as a process).

Incidentally this simplified async KA is also much easier to
implement, requiring no state at the recipient.

-Pieter