Run-Time Monitoring in Service-Oriented Architectures

Abstract

Modern software architectures are increasingly dynamic. Among them, Service-Oriented Architectures (SOAs) are becoming a dominant paradigm. SOAs allow components to be exported as services for external use. Service descriptions (which include functional and non-functional properties) are published by service providers and are later discovered by potential users. Service discovery is based on matching the published service descriptions with the required service specifications provided by the user. Once an external service is discovered, it may be bound and invoked remotely. New services may also be created by composing existing services.

To achieve full flexibility, the binding between a service request and a service provision may be set dynamically at run-time. Dynamic binding and decentralized management of external services by independent authorities, however, challenge our ability to perform verification and validation (V&V). Traditional V&V is a pre-deployment activity. In the new setting it extends to run-time and requires continuous monitoring of functional and non-functional attributes.

This chapter investigates continuous monitoring of SOAs, with particular emphasis on web services. It provides a classification scheme that can help understanding the different monitoring approaches a system designer can choose. It also analyzes the running example and discusses some of the functional and non-functional aspects one might be interested in monitoring in its context. The chapter then presents a short survey of the most important ongoing research in this field and concludes by discussing future research directions.