Container Services for High Confidence Software

For high-confidence systems, substantial effort is expended to ensure that the system will behave in an expected manner. This paper presents the position that a commercial off the shelf Enterprise JavaBeansTM (EJBTM) container can be extended to constrain the behavior of high confidence software. These extensions are based on techniques that are not new; developers of high confidence software use these techniques already. We discuss how adding services to the container allows verification and validation of high confidence properties to be performed at the container level where they will require less revalidation when business logic changes. We present two examples of container augmentations, one based on communication mediators and one based on application monitors. These examples illustrate how method-level preconditions and postconditions, and application-level invariants can be asserted by an EJB container.