Implementation of RAID

RAID is a robust and adaptable distributed system for transaction processing. It is a message-passing system, with server processes on each site. A high-level, layered communications package provides a clean, location independent interface between servers. RAID processes concurrent updates and retrievals on multiple sites. The servers manage concurrent processing, consistent replicated copies during site failures or network partitionings, and atomic distributed commitment. The latest version of the communications package is able to deliver messages in a high-performance configuration in which several servers are linked into a single process. RAID provides the infrastructure to investigate experimentally various methods for supporting reliable distributed-transaction processing. Experiments on handling site failure with partial replication, checkpointing, and alternative communications methods have been performed. Measurements on various aspects of RAID transaction processing performance are presented