Traffic-aware stress testing of distributed systems based on UML models

A stress test methodology aimed at increasing chances of discovering faults related to network traffic in distributed systems is presented. The technique uses the UML 2.0 model of the distributed system under test, augmented with timing information, and is based on an analysis of the control flow in sequence diagrams. It yields stress test requirements that are made of specific control flow paths along with time values indicating when to trigger them. Different variants of our stress testing technique already exist (they stress different aspects of a distributed system) and we focus here on one variant that is designed to identify and to stress test the system at the instant when data traffic on a network is maximal. Using a real-world distributed system specification, we design and implement a prototype distributed system and describe, for that particular system, how the stress test cases are derived and executed using our methodology. The stress test results indicate that the technique is significantly more effective at detecting network traffic-related faults when compared to test cases based on an operational profile.