Section: New Results

Testing peer-to-peer systems

Peer-to-peer (P2P) is one of the major distributed platforms for many applications such as large data sharing and collaboration in social networks. However, building trustworthy P2P applications is difficult because they must be deployed on a large number of autonomous, volatile nodes, which may refuse to answer to some requests and even leave the system unexpectedly. This volatility of nodes is a common behavior in P2P systems and may be interpreted as a fault during tests (i.e., failed node). In this context, we have developed a novel framework and a methodology for testing P2P applications. The framework is based on the individual control of nodes, allowing test cases to precisely control the volatility of nodes during their execution. We validated this framework through an experimentation on the FreePastry distributed hashtable. The experimentation tests the behavior of the system in different conditions of volatility and shows how the tests were able to detect complex implementation errors. This work, published in the Empirical Software Engineering journal [73] , in collaboration with the ATLAS Inria team, is directly related to Triskell's goal to apply software engineering to distributed systems.