[zeromq-dev] Dealer router scenario

[Pieter Hintjens]

On Wed, Jan 30, 2013 at 5:43 PM, James Marcus <marcus.james at gmail.com> wrote:

> When we use the Dealer/Router scenario we can send a message but the dealer
> doesn't get a message back.  We can send a message to the router and the
> message is received by the router, and we can send it back without
> exceptions, but the dealer is blocked on receive.

You don't say what version of 0MQ you're using. Assuming it's 3.2, try
setting the ZMQ_ROUTER_MANDATORY option on the router socket, and then
check for errors. If you're sending with invalid addresses, messages
otherwise get dropped silently. This is the most likely error.

> Remote_lat and local_lat work on the machines. local_thr and remote_thr
> seems like gets are blocked.

Are you by any chance mixing different versions of 0MQ?

> Binding on a PUB socket we use tcp://* throws an exception, is this by
> design?  Because this seems to work on the our development VMs.

You can't bind to "tcp://*", you have to specify an interface and a
port. So, "tcp://*:*" and please read the zmq_tcp man page.

> What are the common issues that block replies to the dealer from the router?
> Can this be an OS/Networking issue, or a bug?

Almost definitely a bug in your application causing the reply address
(first frame of each message) to be incorrect.

-Pieter