Performance analysis in loosely-coupled distributed systems

A great deal of work is currently underway to develop infrastructure for supporting a loosely-coupled computational model over the Internet. This is based on the standardization of Web Services interfaces and protocols to allow application-to-application communication and interoperability using XML messaging[1]. An example of an existing Web Service is the Google search API for programmatic access to Google’s search service[2]. Another is the Microsoft Passport which maintains an online identity for users that can be accessed by other applications for purposes of authentication[3]. With the introduction of comprehensive interoperability standards, it is expected that Web Services will become more and more common. Consequently deployment aspects which remain significant challenges for the service provider need to be addressed, including, among others, performance, configuration, management, security and dependability. This paper considers some of the performance-related issues which must be tackled in order that the potential for Web Services to provide a truly global distributed system be achieved.