On 4/2/07, mnishizawa <[EMAIL PROTECTED]> wrote:
I am looking build an event based system where the event is logged in a message queue and then listeners(subscribers/receivers) all perform their specific tasks based on the event. I've looked at the documentation and I can't seem to find exactly what I want to do. I would like to: - strictly order the subscribers
What does that mean?
- ensure that all subscribers have acknowledged the message before dequeuing
Huh?
- message dropping is not allowed So for instance, say I have general user registration for some application. I would like to have 3 subscribers: 1. register the user, 2. check that the user's location exists, 3. registers the user for services in their location. The ordering is important because 2 is dependent on 1 and 3 is dependent on 2, so we need to make sure 1 has executed before executing 2 and so on.
So send a message to queue 1, then that is completed, send it to queue 2 then 3 etc.
Why not do it in a service? I'd rather not because if one part of the chain fails, the registration fails. I do not want to lose registrations because the location lookup fails.
So uses pipelines.. http://www.enterpriseintegrationpatterns.com/PipesAndFilters.html -- James ------- http://radio.weblogs.com/0112098/
