Home Migration Using a Structured Peer-To-Peer Overlay Network

This paper presents the design and implementation of a decentral- ized home-migration protocol for the Distribution SubSystem(DSS) middleware. The DSS provides generic distribution support for shared data structures in open distributed systems. Previous approaches for migrating homes, such as forward pointers, broadcasts, and centralized directory services are known to have dis- advantages. We propose using a structured P2P system to store the location of migrated homes. This enables seamless migration of homes, without the need for lengthy forward pointer chains that degrade performance and robustness. Nor is a dedicated data-base that requires administrative effort needed. The presented design depicts how the self-organizing aspects of peer-to-peer computing can be used to construct a fault-tolerant, scalable, efficient, distributed home-location service to enhance middleware functionality. This paper describes a decentralized home-migration protocol that uses a structured peer-to-peer (P2P)(1) overlay network to locate migrated homes. The structured P2P network is constructed by the nodes participating in a distributed application. The resulting service inherits the prominent properties of structured P2P systems; self- organization, low administrative load, high guarantees, good scalability, and resilience to failures. The home-migration protocol is made a component of the generic component- based coordination framework of the Distribution SubSystem(DSS) (2, 3) middleware. Home-based protocols are simple to implement and often used to grant seamless access to migrating entities(4, 5). A mobile entity records its current location at a home, usually located at the process where the entity was created. A proxy, that provides seamless communication with the mobile entity, sends messages to the home. In turn, the home forwards the messages to the current location of the entity. The coordination framework of the DSS makes use of the Home/Proxy approach. Each distributed entity is controlled by a consistency protocol, executed over a coordination network of prox- ies, a home(2, 6), and a current location. In many home based protocols the home and the current location are co-located, but it need not be that way.