amqp — archive

[management] Proposal for event notifications (initial outline)

From: Alan Conway
To: [email protected]
Date: Thu, 12 Feb 2015 17:20:00 -0000

On Thu, 2015-02-12 at 09:01 -0800, Matthew Arrott wrote: > +1 Wow, you just ... agree? I don't think that's ever happened to me before on a standards committee :) A note on implementation: the naive way to implement this proposal is to keep a list of filters and iterate over it with each event to decide whether to send to that link. That is linear in the number of links and won't scale with many subscribers. A better way to implement it is to compile all your filters into a decision tree. That gives constant-time look-up (worst-case depth of a branch is limited by the number of event attributes defined) The qpid c++ broker's 0-10 topic matching went through this linear-oops-no-tree cycle so I'm not just making this up. Probably that's not suitable discussion for the spec, but wanted to reassure anyone who was worrying that this might require linear look-up. >