"which may or may not be reused for multiple subscriptions"

[David Hull <dmh@tibco.com>]

I wanted to elaborate on the parenthetical comment I made a few days ago.  I believe there is a strong case to be made for negotiating delivery parameters once (for a distributor), and then using them for a variable set of subscriptions.  For example

• Create a pausable, boxcarring, pausable secure and reliable distributor.
• Use that distributor as the EPR for some subscription.  The resulting notifications are delivered reliably and securely to the ultimate consumer.  Pausing the distributor pauses that subscription.
• Make another subscription with that same distributor.  Both subscriptions can be paused as a unit.  Their messages may be batched together.  The security context is shared.
• Cancel the first subscription.  Everything else continues comfortably.

I believe this could go a long way toward addressing some of the scalability issues to do with controlling multiple subscriptions at the same time.  The subscriptions would still have to be destroyed individually, unless there were some facility for destroying all subscriptions with a given consumer EPR.

A slightly different way of looking at this is that "consumer EPR" is a natural way of grouping subscriptions, and/or that the notion of "distributor" subsumes "subscription group" as a special case.