Overview of Enterprise Application Integration Technologies.
Enterprise Application Integration, or EAI in short, aims at integrating different applications into an IT application landscape. Traditionally, EAI was understood as using the same communication infrastructure by all applications without service-orientation in mind. This meant that the benefits of a shared infrastructure were limited while driving up costs through additional integration platforms.
Service Oriented Architectures (SOA) brought a new paradigm by decomposing applications into reusable and shareable services. Service orientation requires careful design of services. A hierarchic scheme of services may help to define a suitable service decomposition.
While SOA is technically based on big web service technologies, namely SOAP, WSDL and BPEL, WOA or Web Oriented Architecture stands for the lightweight service paradigm. WOA makes use of REST-based technologies like JSON and HTTP.
In many cases, an Enterprise Service Bus (ESB) is used as an infrastructure element to achieve the technical integration of the services. The ESB core functions like message routing, filtering and transformation provide the mediation services required to integrate heterogeneous application landscapes.