The Rainbow Skip Graph: A Fault-Tolerant Constant-Degree P2P Relay Structure

TL;DR

The rainbow skip graph is a novel distributed data structure for peer-to-peer networks that offers high fault tolerance, constant node size, and efficient query/update times for ordered data.

Contribution

It introduces the first fault-tolerant, constant-degree peer-to-peer data structure with fast query and update capabilities for ordered data.

Findings

Supports successor queries with O(log n) messages with high probability.

Achieves fault tolerance with constant-sized nodes.

Improves message complexity over previous structures.

Abstract

We present a distributed data structure, which we call the rainbow skip graph. To our knowledge, this is the first peer-to-peer data structure that simultaneously achieves high fault tolerance, constant-sized nodes, and fast update and query times for ordered data. It is a non-trivial adaptation of the SkipNet/skip-graph structures of Harvey et al. and Aspnes and Shah, so as to provide fault-tolerance as these structures do, but to do so using constant-sized nodes, as in the family tree structure of Zatloukal and Harvey. It supports successor queries on a set of n items using O(log n) messages with high probability, an improvement over the expected O(log n) messages of the family tree.