Social Glass

I came across a post from Dion Hinchcliffe recently that talked about ideas for SOA architects in 2007 (ok, so it’s a year old). Dion talks about how Web 2.0 philosophies can be leveraged to enhance the effectiveness of SOA. The recommendation that stood out to me was “Deeply Embracing URI Addressability”, where Dion argues:

The hyperlink is the fundamental unit of thought on the Web and it should be in your service designs and (hopefully granular) schemas as well. Giving each discrete piece of information, every service, and all content a globally addressable URI instantly gives a service, and the data it carries back and forth across its interface, access to countless new consumption and reuse scenarios.

To illustrate how unique addressability might work, consider an organization that sells insurance to customers. Each customer is given an account number. The organization has an SOA strategy and decides to make use of REST (Representational State Transfer) to expose its information assets, including “customer” in an interoperable manner.

REST “strictly refers to a collection of network architecture principles that outline how resources are defined and addressed” (Wikipedia). It also makes use of the HTTP verbs POST, GET, PUT and DELETE (similar to database CRUD operations) to define what action to take on a given resource.

The insurance company develops a REST interface that sits on top of its CRM system. Customers become uniquely addressable by account number, as follows:

http://insuranceco.corp.com/customer/9886574

where “9886574″ represents the account number for a particular customer. A “GET” request (similar to READ on a database) to this URI might return the customer profile and claim history.

This is what Dion means when he says information should be uniquely addressable. Each customer has his own URI, which means behind the firewall other applications can reference a customer using this address. From here the possibilities are endless, where the intranet starts behaving like the internet. Information assets begin having inbound links, and this “democracy” so famously publicized by Google’s PageRank algorithm (where an inbound link counts as a vote) starts to apply not just to web pages, but to entities abstracted by services in an SOA (like “customer”). In this way information can be:

• Bookmarked in a social bookmarking system. Users include comments, like “Harry Young [customer 9886574] calls in every week and I’m tired of dealing him”. Users also tag these resources in the social bookmarking system, i.e. “disgruntled”, “customer”.
• Searched through an enterprise search engine. Adding “http://insuranceco.corp.com/customer/” to the seed of our enterprise search engine causes all customer information to be natively crawled and indexed.
• Referenced from wiki and blog posts.

As a blanket statement I’d say that any SOA architect should strongly consider exposing resources in this manner so that he can leverage the network effects and unintended uses that are achievable through unique addressability.  Good stuff Dion.