Performance Test Language for Web Services

During the development of Web services and their deployment to a specific target system, organizations need to evaluate if the Web service implementation and the hardware can meet the Quality of Service attributes specified in a Service Level Agreement. One important aspect are performance-related attributes, such as response time, throughput or scalability of the Web service. Typically tests which simulate client behavior are used to evaluate these attributes. In this thesis the domain-specific language QoSTIL (Quality of Service Test Instrumentation Language) is introduced. It allows for the definition of tests and the composition of these tests to create complex test plans which can be used to simulate Web service client behavior and evaluate performance-related quality of service attributes of Web services. Language instances are automatically transformed to executable Java code and result presentation views. These can be used to run the defined tests and visually display the test results. The implementation of the domain-specific language follows the Model-Driven Development approach. Both the language model (abstract syntax), which is based on the meta-model defined by the Frag modeling framework, the concrete syntax, as well as the transformation to executable code are explained in detail in the thesis. Also a review of technologies and development tools is included. These technologies and tools are used for the implementation of the domain-specific language and generation and execution of the runtime system. To evaluate the utility and usability of the language a number of tests which are based on realistic business use cases for assessing certain performance-related quality of service attributes are defined and implemented. After the automatic transformation to executable code, the tests are run for specific Web services and the results are presented and discussed. Furthermore the thesis includes a comparison to the related work in the problem domain.