Difference between EAI and ESB

What really is ESB (SOA term)? What is its main difference with EAI (slightly older term)?

EAI is generally a HUB and SPOKE model of integrating the applications. When we remove the HUB from EAI and replace with a BUS (called ESB - Enterprise Service Bus) it becomes the SOA.

"Web Services" can be developed using multiple technological options can then be put on to this BUS and used by multiple consumers.

The SOA gives the marketplace to buy and sell services as commodity. The standards around the service description, service discovery and service invocation makes it all possible.

ESB is a concept, there are several software tools enabling the implementation of ESB are available in the market. They generally run on a middleware server as an application providing some core functionality around the service choreography and orchestration.

There are also BPEL engines which can do all the functionality of ESB and provide more complex work flow modeling of business processes.

It is an important decision to make between the ESB and BPEL processor manager while providing solutions.

There are instances a classical EAI tool would be sufficient to solve a specific problem where the BPEL based solutions are being implemented!!!!


Links:
Good Link found on the web on this subject: http://emergingtech.ittoolbox.com/documents/soa-vs-eai-vs-esb-12998

Parallel Data Processing in Grid

Functional programming Languages, emphasizing the evaluation of mathematical processing without regarding the state change are on rise to do different analytic operations on the several Petabytes of data especially in search engine and web analytic functions.

The old "lisp" has slowly transformed into the new generation scripting "sawzall" incorporating massive parallel processing using map and reduce functions.

Sawzall is used at Google the famous search engine.