[zeromq-dev] subscribe/unsubscribe refcounting behaviour

[Pieter Hintjens]

On Wed, Aug 18, 2010 at 8:19 AM, Martin Sustrik <sustrik at 250bpm.com> wrote:

> It's needed to be able to aggregate subscriptions from mutliple sources.
> Currently, the subscriptions are not forwarded upstream so both
> refcounting and idempotency would work. Once the subscription forwarding
> is implemented, subscription idempotency would allow one subscriber to
> unsubscribe another one.

So after discussing this with Martin S. on irc, it seems idempotency
could work but would require more sophisticated devices that are able
to track subscriptions and only upstream sub/unsub messages when
needed.  A device that just forwarded messages without looking at them
would indeed allow one subscriber to unsubscribe another one.

-
Pieter