One of the things I often hear about Service Oriented Architecture (SOA), when compared to past architecture styles, is how it is based on industry standards
and sets you free from all kinds of burdens related to integration and interoperability. But, just the mere number of standards and specifications that one has to consider when attempting to SOA is mind numbing. I happened to chance upon one of Thomas Erl‘s (I realized later he has many similar) websites called specifications.ws which shows a (stained-glass-like) mosaic of standards that can put you in a kind of a trance or even a coma if you are not careful. I do like his attempt at distinguishing first and second generation web services. Not only are there many many standards/specifications to consider, you also have to consider:
- Which ones are specifications (not yet standards) by one or more vendors?
- Which ones are specifications (not yet standards) submitted to standard bodies?
- Which ones are specifications ratified by the standard bodies as industry standards?
- Which ones (standards or specifications) overlap (some do) and which to choose / use in such cases?
- And worst of all, there is not a single place to go to for these standards!
On that last note, some of the several standard bodies you run into when investigating SOA standards are W3C, OASIS, DMTF, BPMI, WFMC, IETF, Liberty Alliance, to name a whew! And you will definitely not miss the WS-I effort underway to develop and publish interoperability profiles (not standards) based on accepted standards in the industry. (Note:WS-I is not a standards body.)
In reality there is not any holistic standard for SOA. And I seriously doubt there ever can be, will be such a holistic standard. Although there seems to
be an effort underway at OASIS to create a SOA Reference Model, you won’t learn much about how to do SOA and how all the standards relate in typical SOA environments.
Anyway, after reviewing several specifications and standards, I am exhausted. I am working on putting together a list of all relevant standards and specifications and will publish my take on all this sometime soon.
Meanwhile, if you have any words of wisdom, I am listening.