Research And Design Of Lock Management In Distributed Parallel File System

Distributed file system appeared in 1970s. After 30 years pullulating, it has matured. It has a wide range of applications in data processing, information service, business system, science research, education and other fields. DPFS (Distributed Parallel File System) is an important branch of the distributed file system, also the one of the primary research areas in the future. Lots of advanced technologies are used in DPFS, to increase parallelity of data I/O. As result of good usability of storage network's capability, applications can expect as much as GB or TB level storage bandwidth.DLM (Distributed Lock Management) is an important component of the distributed file system, and the key part that ensure system correctness and data consistency. Because of the high concurrent probability, DLM became more important in DPFS. Basing the study of existing distributed file system and research in lock management, a DLM system, which is flexible, effective and suitable for DPFS, is designed. the distributed C/S architecture gives up the special global lock management server. Multiple lock policies provide optimal lock service for the different file system operations. ACF (Asynchronous Callback Functions) mechanism provides the reverse asynchronous event notification. The system implement is predigested by layered, modularized design, and minimized interfaces.However, the applications'data access model has significant impact on the design of the lock management. Because the traditional extent lock has pitfall under the fine-grained striped data access pattern, DBM (Dynamic Block Management) algorithm is designed. Analysis and simulation results have shown that, DBM can substantially increase the real parallelity, when access granularity is much less than the page size.