Web Services and EAI

[These are my own ideas and viewpoints - So forgive me if I err on facts]

Why All this Hype about Integration?

A few days back, I posted a question on a forum that had folks from Brazil. Most of the folks on the forum knew little English [No offence meant]. As soon as I posted a question, I got a lot of replies in a language that I never knew. From their answers, I could not make out whether they wanted me to re-post the question in their native language, or whether they assumed me to bilingual, and answered to my question in their native language.
I talked to my friend on this, who knew a bit of Spanish. He took a look at the forum and gave the answer I wanted - "We do not know about this - Please try posting in some other forum". Well, I did not get an answer to my question, but I realized that English would not scale anywhere and everywhere. Imagine the forum with a set of people each of whom spoke a different language that was different from every other language. In this case, either the forum would have no postings, or each of them would attempt to convey his/her emotions on the forum on the inconvenience.

Basically, the point I wanted to make here is the fact that there is a very demanding requirement of allowing open communications between entities [may it be people, resources or Applications] to make things easier, better and effective.


Let me try and re-form the earlier example, by assuming it was a forum of Applications that participate in the "forum"[A place to talk to each other]. By the usage "talk to each other", I am referring to the exchange of relevant information between Applications. And why would Applications need to exchange information - because the organization that has these Applications has a composite requirement that would require a combination of the functionalities of these Applications.
Let me explain this with an example. Organization "E-ntelligence" has hired a new employee. There are several things that need to be done on the joining of a new hire. The Human Rersources Personnel would need to update the HR Application with the Employee Information. The Financial Application would need to create a new Entry in its records for the new employee. The Project Tracking Application would position the employee in a particular Business Unit within the organization, reporting to a specific manager.

When it comes to the point where we find that these Applications have been developed by different Vendors, run on different platforms, and have been implemented in different programming languages, complexity grows umpteen fold.

Here comes the notion of integration between Applications within Enterprise - a notion that can rescue the enterprise from extensive expenditure for resources for writing custom code that allows these disparate Applications to talk to each other.

Is Integration EAI, or is there something more to it?

EAI, or Enterprise Application Integration is all about allowing open communication between disparate Applications, irrespective of language, platform, or geographical locaiton.

For instance, you could have an Applicaation that runs on Linux, implemented in C, running on a Server in New Jersey, and another that talks to it, running on Windows XP, implemented in Java, in Bangalore -There's no limit to it.

From an amateurs level, all of this looks really trivial - its all about invoking a few remote procedure calls to the Application with whom you want to talk to, and here we are, with the results we want. But in actuality it isn't so.

Firstly, remote procedure calls make the Applications very tightly bound. The Applications need to know the exact signature of the methods that the want to invoke, and there is a cascade of issues that follow if the contract between the Applications is breached. And it definitely is tied to the language support of the Applications. For instance, if an RMI infrastructure is used for communication, the Applications better be written in Java.

[To be Continued]