A Novel Model and a Simulation Tool for Churn of P2P Network

The prior studies setup the churn model by measuring the historical logs or records of a P2P network, and treat it as one whole black-box without understanding the inside of peer´s population. The metrics used to characterize the churn is distributions of the node session lengths and arrival intervals. We investigate churn in a higher level point of view, and find that modeling it based on the global geographical distribution of peer nodes will result in a system which explain the fluctuation and cyclic phenomenon of network size. This model considers the user behavior pattern into account. Then we provide a Matlab tools that can provide churn events according to this model. From the output events of simulation, we do see some more future things than other models. We might expect or predict when and what nodes would return back, as well as when and what nodes would disappear at high possibility. So it is useful when designing a system optimized both to the pass and the future, which could reduce the overhead of the maintenance of underlying overlay network of DHTs and lower the redundant level of replications for P2P storage system.