[zeromq-dev] Identities as cookies

[Martin Sustrik]

Hi Oliver,

> If this is all sounding feasible...

I personally believe that explicit identities are a misdesigned feature 
and should not be used. So I'm leaving the question to be asnwered by 
those who are in favour of them...

> - How would I poke ZeroMQ to give me a specific delivery tolerance?
> sock.setsockopt(zmq.TIMEOUT, 30 * 1000)

What's delivery tolerance? You mean timouting on recv()? If so, 
currently it has to be done via zmq_poll() which has a timeout parameter.

> - Is there a way to tell the XREP socket on the server to flush any
> backlog/close the underlying tcp socket associated with a particular
> identity?

No.

> - Most importantly, where and how much overhead does the identity impose
> across a single ZMQ-hop?
> client <----wan-but-no-devices---> server
> Is it only in the handshaking? Is it repeated periodically? Or is it a
> per-message overhead?

It only happens when TCP connection is established. It's not even a 
handshake. Each peer just sends the identity and that's it.

Martin