Improving the Peer-to-Peer Ring for Building Fault-Tolerant Grids

Peer-to-peer networks are gaining popularity in order to build Grid systems. Among different approaches, structured overlay networks using ring topology are the most preferred ones. However, one of the main problems of peer-to-peer rings is to guarantee lookup consistency in presence of multiple joins, leaves and failures nodes. Since lookup consistency and fault-tolerance are crucial properties for building Grids or any application, these issues cannot be avoided. We introduce a novel relaxed-ring architecture for fault-tolerant and cost-efficient ring maintenance. Limitations related to failure handling are formally identified, providing strong guarantees to develop applications on top of the relaxed-ring architecture. Besides permanent failures, the paper analyses temporary failures and broken links, which are often ignored.