US Patent 9990372 Managing the level of consistency for a file in a distributed filesystem

The disclosed embodiments disclose techniques for managing consistency for a file in a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in the cloud storage systems; the cloud controllers ensure data consistency for the stored data, and each cloud controller caches portions of the distributed filesystem. During operation, a cloud controller receives from a client a request to access the file. The cloud controller determines a level of consistency that is associated with the file, and then uses this level of consistency to determine whether to communicate with a peer cloud controller when handling the request.