EAI 1.0 MAILINGLIST Avatar
  1. OMG Issue

EAI — It is unclear how a message is associated with a topic

  • Key: EAI-33
  • Legacy Issue Number: 4978
  • Status: closed  
  • Source: Model Driven Solutions ( Ed Seidewitz)
  • Summary:

    Document: UML Profile and Interchange Models for EAI
    Section: 6.4.2 (Topic-based publish/subscribe)

    Description:
    Section 6.4.2.2 discusses the relation between topic-based publishers and subscribers. However, the semantics of an EAIPublicationOperator (see Section 6.4.1.9) require that a message conform to an EAITopicRule (a kind of EAISubscriptionRule) in order to be published on a topic. But it is not clear how to determine that a message is on a topic just from looking at that message. Presumably, messages produced by an EAITopicPublisher (Section 6.4.2.1) are somehow tagged as being on a specific topic, but this is not said explicitly.

    Recommendation:
    At the very least, explicitly state in Section 6.4.2.1 that messages produced by an EAITopicPublisher are such that they satisfy the EAITopicRule for a one or more EAITopics relevant to the EAITopicPublisher. However, if the EAIPublicationOperator can then determine topic(s) for a message just by evaluating a condition on the message, it would seem that the topic(s) must be encoded in the message content someplace, in which case it is unclear what the difference is between an EAITopicRule and an EAIContentRule. Perhaps it would be best just to eliminate EAIContentRule, regarding this as being covered by the general case of EAISubscriptionRule, and have EAITopicRule as a specialized EAISubscriptionRule for which the condition is that the message is on one of a given set of topics. In this case, an association should be added from EAITopicRule to EAITopic with a multiplicity of "1..*".

  • Reported: EAI 1.0b1 — Thu, 7 Mar 2002 05:00 GMT
  • Disposition: Resolved — EAI 1.0
  • Disposition Summary:

    see above

  • Updated: Fri, 6 Mar 2015 20:58 GMT