11. Web Services Performance

Service Oriented Architecture (SOA) is an architectural style that enables complex business applications to be built from smaller individual services distributed over the network. It has become the industry’s de facto standard for building and deploying business solutions that are agile enough to meet the demands of business partners and customers. Web services have emerged as the most widely used technology for implementing SOA. A Web service is a software system accessible over a network that supports machine-to-machine interaction. It is a platform and programming language neutral system that exposes standardized interfaces accessible over a set of standard Internet communication protocols; typically described using Web Services Description Language (WSDL). Web services communicate using the Simple Object Access Protocol (SOAP) and use eXtensible Markup Language (XML) for describing the exchanged messages.

With increasing SOA adoption by enterprises, both new and existing enterprise applications are being exposed as Web services. The loose coupling enables enterprises to harness the power of existing services more efficiently. However, this also brings new challenges, especially in terms of performance and scalability, as the same services are invoked by a large number of clients. Performance and scalability should be important considerations in the design, implementation, and deployment of Web services. In this chapter we look at different aspects relating to Web service performance: how to measure Web service performance, the important factors that affect performance, and best practices for commonly encountered use cases.