CEP Enhances SOA's Eventing Capabilities

Eventing in a SOA environment is crucial for enterprise applications. According to the WS-Eventing specification, web services are capable of monitoring and notifying status and also performing a defined operation when a certain event is triggered. However, like any other specification that explains web based extensions to event driven architectures, this lacks the true power of making decisions on events based on a stream of events itself.

The combination of CEP and SOA unleashes the true potential of a complete event driven architecture implemented over a web based or any similar network communication protocol based architecture that is supported by existing SOA networks. Thus, one could describe CEP over SOA as a universal replacement to existing Publisher-Subscriber systems such as,

1. JMS Topics
2. XMPP
3. WS-Eventing
4. Atom Pub/Sub

Decisions made through CEP systems involve identifying meaningful events from a number of events, extracting the product of a reaction between several events, understanding event patterns etc. The possibilities in handling bulky event sources are immense. Thus, the positive addition to an SOA environment through a CEP system is limitless.

It is clearly understood that CEP enhances SOA's eventing capabilities. In addition to these marginal gains, a complete CEP installation over an SOA network makes you more productive. We are looking forward to introduce such other benefits.

Unified Support for Events

This time I would like to mention a few words about another phase of our project - Unified support for events on the Synapse ESB.

This will probably be one of a few postings which will describe this matter. This particular posting simply is intended to lay down some initial background to this concept and introduce a few key terms. It will not be describing the process of unified support, but rather the different types of requests handled by Synapse which results in event formulation.

Some of the different types supported are;

• XMPP Pub/sub
• Atom Feeds
• JMS Topics
• WS-Eventing

Looking at these in a bit more detail;

• XMPP -
  If you usually do a considerable amount of chatting over the internet, chances are you have used this technology at least once... it is the backbone of some popular systems such as Google Talk. XMPP is essentially an XML-based protocol which enables real-time and extensible Instant Messaging feature core (e.g. it is the base of Jabber IM as well as Presence Technology.

• Atom -
  The Atom format was developed as an alternative to RSS. It is a data format used for providing users with frequently updated content.
  
  
• JMS Topics -
  API is a Java Message Oriented Middleware API for sending messages between two or more clients.
  
  
• WS-Eventing -
  a protocol that allows Web services to subscribe to or accept subscriptions for event notification messages.
  

Our goal therefore in brief is giving Synapse the ability to interpret as well as handle these different types of events in unified manner. More on this soon...:-)