Networking

This paper discusses an efficient approach to design and implement a highly available peerto-peer system irrespective of peer timing and churn. Although peers in P2P system join or leave at whim, it has been found that most of the peers follow diurnal pattern of availability governed by the time of day effect. When considering a global P2P system, the cyclic behavior of peers situated on different time zones can be found complementary of one another. Our approach utilizes the diurnal pattern of globally dispersed peers to develop a grouping strategy. The objective of each group is to ensure 24x7 data availability within the group. To represent availability pattern we propose to divide 24 hours of a day into multiple slots and then to express the availability of a particular peer in each slot. In our approach, each peer collects slot availability information of a number of peers and forms small groups of 4 to 8 peers in such a way that the combined availability in each slot within a group is close to 100%. Simulation results show that our protocol converges fast and ensures high availability for each group with minimal overhead.