The Approach of Web Services Parameter Mutation Operators Based on the Rules Model

Web services have implemented the characteristic such as interoperability and accessibility furthest, making its fault tolerance very important. Use the method of fault injection to test Web services can thoroughly validate its fault tolerance. Existing researches mostly focus on the fault injection at the network layer, or the individual parameters of SOAP (Simple Object Access Protocol) messages or XML document formats, thereby there is lack of considering on the rules mutation among the parameters of Web services. This paper proposes a approach of Web services parameter mutation operators based on the Rules Model. First, Use 12 operators such as "=", "<", ">", "+", "-" to construct atomic rule model which represent the relations among the parameters of Web services or among the parameters and constant. Then combine atomic rule model to multiply rule model using "and", "or". At last, use the SMT solver the multiply rule model to generate mutation data that violates the constraint rules, and inject it into SOAP messages for testing. This approach can effectively assess the validity of business rule implementations in Web services.