Test-and-Adapt: An approach for improving service interchangeability

Service-oriented applications do not fully benefit from standard APIs yet, and many applications fail to use interchangeably all the services that implement a standard service API. This article presents an approach to develop adaptation strategies that improve service interchangeability for service-oriented applications based on standard APIs. In our approach, an adaptation strategy consists of sets of parametric adaptation plans (called test-and-adapt plans), which execute test cases to reveal the occurrence of interchangeability problems, and activate runtime adaptors according to the test results. Throughout this article, we formalize the structure of the parametric test-and-adapt plans and of their execution semantics, present an algorithm for identifying correct execution orders through sets of test-and-adapt plans, provide empirical evidence of the occurrence of interchangeability problems for sample applications and services, and discuss the effectiveness of the approach in terms of avoided failures, runtime overheads and development costs.