A Peer-To-Peer Infrastructure for Resilient Web Services

This paper describes an infrastructure for the deploy-ment and use of Web Services that are resilient to the failure of the nodes that host those services. The infra-structure presents a single interface that provides mecha-nisms for users to publish services and to find the services that are hosted. The infrastructure supports the auto-nomic deployment of services and the brokerage of hosts on which services may be deployed. Once deployed, ser-vices are autonomically managed in a number of aspects including load balancing, availability, failure detection and recovery, and lifetime management. Services are published and deployed with associated metadata de-scribing the service type. This same metadata may be used subsequently by interested parties to discover ser-vices. The infrastructure uses peer-to-peer (P2P) overlay technologies to abstract over the underlying network to deploy and locate instances of those services. It takes advantage of the P2P network to replicate directory ser-vices used to locate service instances (for using a ser-vice), Service Hosts (for deployment of services) and Autonomic Managers which manage the deployed ser-vices. The P2P overlay network is itself constructed using novel middleware based on Web Services and a variation of the Chord P2P protocol, which is self-configuring and self-repairing. 1