ABC of EAI Layers

In the last post, we briefly touched upon the black art of XML. It was meant to be an introduction to the technology as you will need it as an integration developer. We will definitely go deep into XML once we dive into implementation specific topics. However, today we will talk about the layered approach towards EAI. As you would have figured out by now, there is no simple answer to the demands of EAI. Hence we need to arrive at an integration architecture in different steps or in other words, “layers”. The idea is to break the problem into smaller manageable chunks and solve each sub-problem step-by-step. It will be easy to understand this if you visualize this in terms of the seven layers of ISO OSI used in network architectures.
The vital layers, or processes in application integration are as follows:
(1) Platform, i.e. hardware integration
(2) Data Integration
(3) Interface Integration
(4) Business Method Integration
(5) Presentation Integration
(6) B2B (inter EAI) Integration, aka B2Bi

Let us peep into each layer very briefly to understand the gist of each concept.
(1) Platform integration is all about the integration of your hardware.Today most hardware platforms use open standards so these are easy to integrate. However, difficulties can arise with the integration of old platforms that vendors do not support anymore. Platform integration also is a major concern if proprietary solutions have been used.

(2) Data Integration is often the start of the application integration process. It involves integration data stores and having a common way to access data across multiple application data repositories. A related issue in data integration is called schema integration that actually deals with the data redundancy and semantic anomalies due to years of usage.

(3) Interface Integration is the reuse of existing functionality from different applications on the basis of a common contract i.e. interface. A common paradigm helps achieve the interface integration. Usage of a common middleware is a simple design pattern to enable interface integration. Using MOM, RPC, or an ORB based standard APIs, integration architects can achieve interoperability and reuse functionality without duplication.

(4) Business Method, Presentation and B2Bi are much detailed topics and I will cover these in detail in my later posts. It suffices to say that a common UI + Middleware + EIS structure facilitates these layers to communicate.

Now that we understand what are the different layers that we need to understand and cater to, I will introduce you in my next post, to the different J2EE APIs that help us attain harmony in these layers. We will look at the entire J2EE based EAI solution space keeping in mind these 6 layers.