Maintaining the Ranch topology

Abstract

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

Dynamic networks

“…The algorithm must deal with nodes joining and leaving the network (churn) by adjusting the overlay network. Examples of protocols that deal with continual concurrent joins and leaves controlled by an adaptive worst-case adversary are given, for instance, in [29,32]. In the examples given above, the overlay changes only as a response to changes in the set of participating peers; other algorithms, such as those given in [20,22,33], induce a constantly-changing overlay even when the set of participants remains static.…”