Patent attributes
The disclosed embodiments disclose techniques for transferring and caching a cloud file in a cloud controller. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more cloud storage systems; the cloud controllers cache and ensure data consistency for the stored data. During operation, a cloud controller receives a client request for a data block of a target file that is stored in the distributed filesystem but not currently cached in the cloud controller. The cloud controller initiates a request to a cloud storage system for a cloud file containing the requested data block. While receiving the cloud file from the cloud storage system, the cloud controller uses a set of block metadata in the portion of the cloud file that has already been received to determine the portions of the cloud file that should be downloaded to and cached in the cloud controller.
