Semantic Brokers

One more development adds nicely to the concept of an enterprise message model: the concept of a semantic broker. Most integration brokers provide message routing and message mapping, but no further semantic translation. A semantic broker is similar in concept to a message broker in that it is an intermediary between application systems, but it goes considerably further than a message broker.

The semantic broker is a product that greatly aids the process of building and maintaining an enterprise message model, and especially the process of adapting each of the application systems to the model. A semantic broker contains a semantic model that is a core representation of the shared concepts in the enterprise. With the aid of tools provided by the semantic broker vendor, the integrator defines a mapping from the application to the semantic model. Each of the products differs somewhat in what is done next. I'll describe how several representative products work to help with the semantic broker concept.

Contivo

Contivo^[92] is a design-time semantic broker. Its tool set allows the integrator to build a map from the source system to a semantic model. The tool then translates the map into a run-time component based on the middleware and architecture in place. One of the strong points of this approach is that it does not tie the enterprise to a proprietary run-time product. Another feature of the tool suite is "transitive association," meaning that once a map has been created from one application to the semantic core, all other interfaces that use the shared concepts are ready to go. This dramatically reduces integrator workload.

Unicorn

Unicorn^[93] is a semantic broker that has many of the same features as Contivo, such as supporting a single central representation to which each of the applications is mapped. Unicorn has its own run-time engine, which enables it to support EAI and "extract transport and load" (a technique for loading data warehouses) without the need for additional middleware. Unicorn is able to import existing models captured in entity relationship diagrams (e.g., ErWin) or UML-based tools, such as Rational.

Ontoprise

Ontoprise^[94] is a German company that also provides a semantic broker capability. Ontoprise's primary tools are ontology editors. Its primary market is in the B2B marketplaces, where resolving the discrepancies between product vendors' catalogs is a huge semantic problem.

^[92]See http://www.contivo.com/ for further information.

^[93]See http://www.unicorn.com/ for further information.

^[94]See http://www.ontoprise.com/ for further information.