Implementing SOA: Total Architecture in Practice

Chapter 33. Stateless and Stateful Failover

Stateless and Stateful Components

When you want a business process to be fault-tolerant or highly available, at least some of the components must be implemented in such a way that should they fail to do their job, a backup component can take over that responsibility. There are two distinct cases to be considered:

1. Stateless component: A component that performs stateless atomic operations that use no reference data (data that is not provided as an input) and save no data. The operations simply take an input and return an output—like an addition operation.

2. Stateful component: A component that performs an operation that saves information and uses that information in subsequent operation invocations. ...