Abstract: The disclosed embodiments disclose techniques for maintaining global name consistency for a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more 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 a client request to perform a namespace operation upon a filesystem object. The cloud controller contacts the cloud controller that manages (“owns”) the portion of the global namespace for the distributed filesystem that includes the filesystem object. This second cloud controller ensures the consistency of the filesystem object across the distributed filesystem during the namespace operation.

Abstract: The disclosed embodiments disclose techniques for sending interim notifications to clients of a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more 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 a client request to perform a namespace operation upon a filesystem object. The cloud controller determines that it will need to contact at least one of another peer cloud controller or a cloud storage system to service the request, and sends an interim notification to the client to notify the client that the request is pending.

Abstract: 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.

Abstract: The disclosed embodiments disclose techniques for maintaining global name consistency for a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more 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 a client request to perform a namespace operation upon a filesystem object. The cloud controller contacts the cloud controller that manages (“owns”) the portion of the global namespace for the distributed filesystem that includes the filesystem object. This second cloud controller ensures the consistency of the filesystem object across the distributed filesystem during the namespace operation.

Abstract: The disclosed embodiments disclose techniques for sending interim notifications to clients of a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more 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 a client request to perform a namespace operation upon a filesystem object. The cloud controller determines that it will need to contact at least one of another peer cloud controller or a cloud storage system to service the request, and sends an interim notification to the client to notify the client that the request is pending.

Abstract: 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.