Hierarchical Replica Location Service Based on Hybrid Overlay Platform

An important problem that confronts data grid applications is to efficiently locate the node that stores a particular data replica. This paper proposes a hierarchical replica location service (HRLS) based on a hybrid overlay platform to address this problem. The system architecture of the HRLS is defined recursively. The granularity of nodes can be tuned flexibly according to system needs. Lookup messages can be resolved level by level moving gradually towards the destination node. There are two kinds of metadata; one is user-defined and the other is system-oriented. Every kind of data has its own bidirectional mapping rule for the metadata. This also helps system security because mapping rules and data can only be accessed by authenticated users. The HRLS has been implemented in an enterprise data grid which was spread over four cities. Results from measurement and the implemented system show that the HRLS successfully met the design goals