Many thanks James (and thanks Guillaume too!) - I understand all the options I think.
But I am still confused about the relationship between WS-Notification and JBI, is it that NotificationBroker is "just another service" on the bus? so its not a JBI spec level thing ... so it is not necessarily going to be a feature of every JBI compliant ESB? thanks David -----Original Message----- From: James Strachan [mailto:[EMAIL PROTECTED] Sent: 28 September 2005 17:02 To: [email protected] Subject: Re: [servicemix-user] Publish subscribe MEP with JBI / ServiceMix ? On 28 Sep 2005, at 15:25, David Black wrote: > Hi, > > I'm wondering does ServiceMix, or more to the point JBI, support a > publish > subscribe type service? What I mean by this is: a service notifying > one or > more clients of some events the clients are interested in over > time. Its not > clear to me looking at the JBI 1.0 spec and at the ServiceMix docs > that this > is supported - but maybe I'm way wrong here :) > > When I look at the 4 MEPs, I see: > > One-Way > Reliable One-Way > Request-Response > Request-Optional Response > > I don't see e.g. Request-Multiple Responses ... > > Any help much appreciated So from WSDL's perspective (and JBI follows the logical WSDL model), you only see these basic MEPs. For topic notifications, some node in the network does a one-to-many as an internal feature of its service (rather like a BPEL engine might generate lots of different invocations on many services over time as a response to a single inbound message). However each message sent to a consumer is still a regular MEP - e.g. a JBI InOnly. e.g. consider JMS. Each interactions with the JMS broker itself is an InOnly, its the JMS broker itself which performs the fan out (sending many InOnly exchanges to different services). So a MEP is from the perspective of 2 clients only, not many clients. ServiceMix supports publish & subscribe routing, which allows one-to- many routing of a JBI components output to many endpoints (whereas the normal is just 1-1 in JBI). http://servicemix.org/Publish+and+Subscribe+Routing In general WS-Notification is the WS/WSDL version of JMS pub/sub; you interact with a NotificationBroker as a service using an InOnly / InOut and it does the fan out for you. So a full pub/sub system using WS protocols still sticks to the core MEPs. Did that help explain it? James ------- http://radio.weblogs.com/0112098/
