Friday, October 25, 2013

HealthCare.gov is a service orchestration

There are a lot of news recently about the healthcare.gov website issues. The terms of hub and service have been used widely to describe the technical nature of the system to general audience like this. It is good that they did not use the more technical term of orchestration. Scalability issues are intrinsic to orchestrations that are realized by a hub-spoke structure.

The central conductor service resides at the hub, and clients and partner services are at the spoke ends.
1. The central conductor service needs to support many concurrent orchestration instances and handle more Input/Output (i/o) operations than normal services, which can bring more performance and scalability challenges.
2. The central conductor service is a single point of failure and, therefore, is critical to the reliability of a service composition.
Such scalability issues and an architectural approach to addressing it are discussed in my thesis titled RESTful Service Composition. The key idea is to implement a composition in a flow-like structure rather than hub-spoke.