A method, apparatus and computer product wherein means and mechanisms are provided whereby, in a distributed or clustered shared file system, (1) concurrency classes may be defined specifying granularity of locking, whether locks are cached, and whether modified data is written-through at the completion of updates, (2) certain files, file types, or files and/or file types as used by given applications or classes of applications, may be associated with concurrency classes, and (3) for each usage of a file by an application, the associated concurrency class determines a policy for choosing specific concurrency and coherency control mechanisms to be used for accessing the given file.