Maintaining the Ranch topology

Topology maintenance, or how to handle the possibly concurrent joining and leaving of nodes, is acentral problem for structured peer-to-peer networks. A good topology maintenance protocol should runefficiently, fully maintain the topology, and should not unduly restrict concurrency. In this paper, wepresent such a protocol for a multi-ring topology called Ranch. The protocol is efficient: for each joinor leave, it uses a logarithmic number of messages with high probability. The protocol fully maintainsRanch after joins and leaves, and allows for a high degree of concurrency. To our knowledge, this isthe first maintenance protocol that enjoys all of these properties for a structured peer-to-peer networktopology.