The many faces of publish/subscribe

Abstract

Well adapted to the loosely coupled nature of distributed interaction in large-scale applications, the publish/subscribe communication paradigm has recently received increasing attention. With systems based on the publish/subscribe interaction scheme, subscribers register their interest in an event, or a pattern of events, and are subsequently asynchronously notified of events generated by publishers. Many variants of the paradigm have recently been proposed, each variant being specifically adapted to some given application or network model. This paper factors out the common denominator underlying these variants: full decoupling of the communicating entities in time, space, and synchronization. We use these three decoupling dimensions to better identify commonalities and divergences with traditional interaction paradigms. The many variations on the theme of publish/subscribe are classified and synthesized. In particular, their respective benefits and shortcomings are discussed both in terms of interfaces and implementations.

A Framework for Event Composition in Distributed Systems

“…All the primitive events that it subscribed to and the resulting composite events were located on the server JMS 2 . CED 2 then detected the complete expression C and output its composite events to a different server JMS 1 .…”

“…Components either act as event sources and publish new events, or event sinks and subscribe to events by providing a specification of events that are of interest to them. A publish/subscribe (pub/sub) communication layer [1] is then responsible for disseminating events; for efficiency, it can often also filter events by topic or content, according to client specifications.…”

Topic Based Agent Migration Scheme via Publish/Subscribe Paradigm

“…Producers publish the events that they generate and messaging middleware or message broker notifies interested subscribers of events when they are published by the producers via store and forward function. As stated in [6] Publish/Subscribe is an event based messaging where it varies by subscription schemes such as topic-based and content-based. Topic based scheme groups subscribers of same type of event of interest.…”

Distributed Execution of S-BPM Business Processes

“…The message broker is a logically centralized component responsible for distributing messages arriving from multiple publishers to its multiple subscribers. Publish/subscribe has the following characteristics [22]: -Space decoupling: producers do not individually address consumers while publishing messages. Instead, they publish messages through the message broker, and subscribers receive these messages indirectly through the message broker.…”