Skip Graph, one of the structured overlays, provides a scalable network owing to the routing path lengths of O (log n), where$n$denotes the total number of nodes. However, there is a problem that most of the routing paths are quite longer than the shortest paths because each node in the network knows only its neighbors, rather than the global topology. In general, long routing paths lead to long delay times and low fault tolerance. Herein, we propose Detouring Skip Graph, which shortens the path lengths through the use of detour routes. It does not require construction of extra links or modification of its topology; thereby, it can succeed in shortening them while maintaining the advantages of Skip Graph. The evaluation experiments show that the average path length was shortened by approximately 20%-30% in comparison with Skip Graph.

A distributed doubly linked list (or bidirectional ring) is a fundamental distributed data structure commonly used in structured peer-to-peer networks. This paper presents DDLL, a novel decentralized algorithm for constructing distributed doubly linked lists. In the absence of failure, DDLL maintains consistency with regard to lookups of nodes, even while multiple nodes are simultaneously being inserted or deleted. Unlike existing algorithms, DDLL adopts a novel strategy based on conflict detection and sequence numbers. A formal description and correctness proofs are given. Simulation results show that DDLL outperforms conventional algorithms in terms of both time and number of messages.