What is Service-Oriented Architecture - Canonical Data Model

You won't be doing Service-Oriented Architecture (SOA) for long before you encounter the concept of a Canonical Data Model (CDM). The idea is that you analyse your business processes, and derive a set of standard data types that you model using XML schema and use in your services - the Canonical Data Model. Perhaps you go one step further and bring in an industry model like IBM's IFW and use that as a starting point.

In the real world however, there is an estate of legacy systems that will tend to have a narrower view of data types than that proposed by the CDM. Some will only be interested in a particular aspect of the CDM types, some subset of the attributes, whereas others will have a different view completely. The issue is that there are different ways to model things.

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What do I put in my SOA service registry?

I'll talk later about asset management, but for now, what exactly belongs in the Service Oriented Architecture (SOA) service registry?

Well, services obviously, stupid.

But what about stored procedures? Or legacy, remotely invokeable services? Or batch feeds? Or ETL (Extract Transform and Load)?

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SOA Service Registry/Repository

How exciting. At long last I am a working somewhere with thousands of services, a SOA registry/repository, a service registrar and established governance processes around the use of services.

Could life get any better for an SOA believer?

Yes, because unfortunately some groups have decided that all this stuff is too much bother and have come to a peer-peer arrangement regarding the use of services.

So the registry is inaccurate.

So the whole house of cards collapses in a horrible, useless heap.

You see, reuse like recycling only works if the there are practical as well as ideological reasons for doing it. In this case either the governance was not strong enough, or the populace were not sufficiently bought into the enterprise benefit of SOA. Take your pick.

Lesson? A registry does not an SOA make, whereas an organisation (emphasis on organise) just might have a chance.

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