NASA Global Change Master Directory: an implementation of asynchronous management protocol in a heterogeneous distributed environment

The Global Change Master Directory (GCMD) is an earth science repository that specifically tracks research data on global climatic change. The GCMD is migrating from a centralized architecture to a globally distributed replicated heterogeneous federated system. One of the greatest challenges facing database research is the integration of heterogeneous systems without compromising the local autonomy, reliability and transparency of the various databases that are participating in the integration. This paper discusses these challenges in the context of the design and implementation of the next version of the GCMD software (Version 8.0). The proposed system has been designed and developed using an object-oriented system architecture based on Java, RMI (Remote Method Invocation) and JDBC. This system enables other sources to be integrated into the GCMD system, with limited changes to the local system itself. This paper describes the components of the GCMD system and addresses the issues of heterogeneity, distribution and autonomy.