Questions about events

[Alejandro Abdelnur <Alejandro.Abdelnur@Sun.COM>]

Hi there,

I have the impression we are a little unorganized right now :).

Following is a list of questions I think it will help us to define the 
scope and some high-level characteristics of the eventing model we want 
to build. Once we agree on the answers to these we can create a second 
set of questions based on the answers to the first set and so on.

  1. Are events categorized?
  2. What is in the payload of an event?
  3. Who can send events?
  4. Who receives and processes events?
  5. Are senders and receivers aware of each other?
  6. Are events synchronous or asynchronous?
  7. What is the scope of an event delivery?
  8. Is there an event broker, or the producers distribute the events?
  9. Do we need to support event sequences (new events as a response
     of an event processing)?
10. What is the distribution model, P2P or Pub/Sub?
11. How an event-creator and an event-listener advertise the events
     they create/produce?
12. How does an event-listener do a binding to receive events?


My answers:

  1. Yes, with a name.
  2. String name-value pairs.
  3. Portlets, through the producer.
  4. Portlets, through the producer.
  5. No.
  6. Synchronous, upon delivery the call is blocking until ends 
processing.
  7. a user request, an event is sent and processed during a single user 
request.
  8. Yes, the consumer acts as a broker.
  9. Yes, they broker keeps distributing/receiving/distributing events 
until there are not more events.
10. Pub/Sub, using the event category name.
11. In their portlet descriptor.
12. Mapping in the consumer (a la user categories)


I hope this approach helps.

Alejandro