Experimental evaluation of peer-to-peer applications

Simulation has been the most widely used approach for performance evaluation of peer-to-peer applications because it represents a fast and inexpensive way to test novel solutions. Nonetheless, the growing complexity and heterogeneity of the emerging scenario for peer-to-peer applications has made it necessary to validate models and simulation results through experimental evaluation in realistic settings. Performing an experimental evaluation of distributed applications on a large scale, however, is still a challenging task. Firstly, it requires resources which should be made available to the community of researchers through a cooperative effort of institutions. Secondly, but not least important, it should be conducted with a sound methodology and produce results that could be analysed and reused by the whole community of researchers. Our call for papers explicitly asked for contributions illustrating either experiences in conducting real-world experimental analysis of peer-to-peer applications or innovative methodologies that could be useful for assessing such applications with respect to non-functional requirements, such as performance, scalability, fault tolerance, availability and security. This editorial presents the main contributions provided by the six papers that we present in this special issue on.