Patent ID: 7254578

Claim:
In a distributed computer system with a shared file system, a method for managing concurrency and coherency of files, comprising: defining a number of concurrency classes in a concurrency class table; specifying files and applications to be associated with each concurrency class in a file/application concurrency class policy table; and determining granularity of locking, caching of locks, and write-through of cached data, to a file server, policies to be used for files and applications in accordance with an associated concurrency class, wherein said concurrency classes include: a default concurrency class in which granularity is at the file level, a cache lock is used, and there is no write-through; a shared file concurrency class in which granularity is at the file level, a cache lock is used, and there is write-through; an update file concurrency class in which granularity is at the file level, no cache lock is used, and there is write-through; a default data concurrency class in which granularity is at the block level, a cache lock is used, and there is no write-through; a shared data concurrency class in which granularity is at the block level, a cache lock is used, and there is write-through; and an update data concurrency class in which granularity is at the block level, no cache lock is used, and there is write-through.