[zeromq-dev] [PATCH] Introduce ZMQ_ROUTER and ZMQ_DEALER sockets

[Pieter Hintjens]

On Mon, Jun 20, 2011 at 2:08 PM, Ian Barber <ian.barber at gmail.com> wrote:

> This seems to open the possibility of getting unintended duplicate identity
> issues.

Yes, it's possible to have two outgoing TCP connections using the same
temporary ports. This could create weirdness in edge cases. To be
evaluated against the benefits of a printable and informative peer
address. I don't think there's any specific issue with NAT.

> For PGM I guess it
> would have to be the interface IP address, though we don't have an easily
> distinguishable port there do we? AFAIU you could have multiple publishers
> on one box pushing from the same interface onto the same multicast IP/port?

For PGM it would probably have to be the multicast group address.

> I think there would need to still be the leading null or similar to
> distinguish generated identifies from manual identities, or are manual
> identities being ditched completely in 3 (I am fine with that :)).

My vote would be to ditch manual identities after looking carefully at
applications that use them, and designing alternative patterns. E.g.
for durable pubsub we have the Clone pattern.

-Pieter