Re: [wsdm] Notification on several topics issue for WS-Notification

[Steve Graham <sggraham@us.ibm.com>]

Currently, the mechanism to communicate
"which topic matched the message" back to the consumer is in
the Notify message.  The Topic component of this message is in the
current WS-BaseNotification draft [1], the normative text associated with
this component is:

/wsnt:Notify/wsnt:NotificationMessage/wsnt:Topic

The TopicExpression describing exactly one Topic - the Topic that is associated with this NotificationMessage. This element describes the topic that matched to a subscription, causing the NotificationProducer to send the Notify message to the NotificationConsumer.

/wsnt:Notify/wsnt:NotificationMessage/wsnt:Topic/@Dialect

The dialect used in the TopicExpression. This must be the same dialect used by the Subscriber when it created the Subscription that yielded this notify message.

Which to me reads only one Topic.

The question to the WSN tc is: what are the tradeoffs to relax the "on topic only" restriction on the Topic component and allow arbitrary TopicExpressions, including FullTopicExpression that would allow conjunction expressions.  Another alternative is to change the maxOccurs on this component to unbounded, allowing multiple simple TopicExpressions, one expression for each Topic that the message matched on AND was referenced in the subscription associated with the consumer.

sgg

[1]http://docs.oasis-open.org/wsn/2004/06/wsn-WS-BaseNotification-1.2-draft-03.pdf
++++++++
Steve Graham
(919)254-0615 (T/L 444)
STSM, IBM Software Group, Web services and SOA
Member, IBM Academy of Technology
<Soli Deo Gloria/>
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"Sedukhin, Igor S" <Igor.Sedukhin@ca.com>

02/17/2005 01:48 PM

To	<wsdm@lists.oasis-open.org>
cc
Subject	[wsdm] Notification on several topics issue for WS-Notification

When a message can be emitted on several topics and the subscription is with the * matching all of the topcs, can a messge be emitted for that subscription indicating a bag of topics it belongs to. This is, instead of emitting several messages, one per each topic matching the subscription.

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
-- (631) 342-4325 .. 1 CA Plaza, Islandia, NY 11749