Distributed File Service Based on Optimistic Concurrency Control

摘要

Principles for a distributed file and data base system that leaves a large degree of freedom to users are presented. It can be used as an efficient storage medium for files, but also as a basis for a distributed data base system. An optimistic concurrency control mechanism, based on the simultaneous existence of several versions of a file or data base is used. Each version gives clients a consistent view of the contents of the file at the time of the version's creation. How this mechanism works, how it can be implemented and how serializability of concurrent access is enforced are shown. A garbage collector that runs independent of, and in parallel with the operation of the system is presented.