Testing Web Services

Web Services form the basis, not only of standard web based eCommerce applications but also the new Globus implementation of Open GRID Systems Architecture (OGSA). Given the prominence of this technology, test methods and tools are required to ensure that robust, fault tolerant software services are deployed. Testing is required not only to uncover existing problems with the system but to also provide potential users with metrics to compare similar serviced based solutions. Fault injection is a well-proven method of assessing the dependability of a system. Although much work has been done in the area of fault injection and distributed systems in general, there appears to have been little research carried out on applying this to web service based systems [1, 2]. Previous research in the field of service testing via fault injection has concentrated on tightly coupled, RPC based distributed systems [1]. In defining a testing method for web services new sets of challenges are faced which require different solutions. Key differences that are encountered when testing web services are: (1) greater chance for network failure, (2) higher levels of security and encryption, (3) more generic nature of the platform and the need to support multiple programming languages, (4) timing constrains and the asynchronous nature of web service operations. This is due to the loosely coupled nature of typical SOAP based systems that implement services.