The Publish/Subscribe Coordination Design Pattern Günter Grossberger

Overview Motivation CORSO Middleware Properties of the Publish/Subscribe Coordination Design Pattern Reliable Information Dissemination Scalability Summary

Publish/Subscribe Systems MQSeries, TIBCO/Rendezvous, NDDS, Minstrel Most based on expiry Best effort information dissemination Not suited for business applications

CORSO Middleware

Properties of the Publish/Subscribe Coordination Design Pattern Subscription Asynchronous communication Content selection Open system Mobile/offline operation Secure (authentication, encryption) Synchronization possible at Subscription

Reliable Information Dissemination Every Subscriber acknowledges every processed PublishItem Garbage Collector gives feedback to application

Reliable Information Dissemination Combination of unreliable and reliable objects Application is returned a recovery status Recovery status depends on accessible objects: unreliablereliable process failureyes site failurenoyes first startno

Scalability Transparent Proxy component Reduces network traffic Utilizes CORSO distribution strategy Acknowledges processing for whole subtree Multiple layers of Proxies

Conclusion Asynchronous communication Open system Reliable information dissemination Scalability (Proxy)  The Publish/Subscribe Coordination Design Pattern is a highly useful tool for the development or integration of business applications