A Fault Injection Method for Testing Dependable Web Service Systems

Testing Web services performance and their Fault Tolerance Mechanisms (FTMs) are crucial for the development of today's applications. Testing the performance and FTMs of composed service systems is hard to measure at design time because service instability is often caused by the nature of the network. Using a real internet environment for testing is difficult to set up and control. We have developed a fault injection toolkit that emulates a WAN within a LAN environment between composed service components and offers full control over the emulated environments in addition to the ability to inject network-related and application specific faults. The tool also generates background workloads on the tested system for producing more realistic results. We describe an experiment that has been carried out to test the impact of fault tolerance protocols deployed at a service client by using our fault injection toolkit.