Abstract: The disclosed embodiments disclose techniques for managing a distributed cache in a cloud-based distributed computing environment (CBDCE). During operation, an instance of a data processing layer service (DPL) receives a data request from a client that specifies an address and an operation for a target data block. The DPL instance uses these to determine a first cache instance of the distributed cache that is assigned to cache a metadata entry that links the address with a data block fingerprint for the target data block. The DPL instance then uses the data block fingerprint and the cache mapping to determine a second cache instance that is assigned to store the target data block, and then accesses the second cache instance to complete the operation for the target data block.

Abstract: The disclosed embodiments disclose techniques for accessing a scale-out block interface in a cloud-based distributed computing environment (CBDCE). During operation, an instance of a block device service (BDS) receives a data request from a client. The BDS instance translates the data request into a set of data block accesses, and then sends the translated data request to a data processing layer service (DPL). The DPL instance services the data request using a set of data operations that leverage one or more of a distributed cache, a distributed database, and a cloud storage system. The BDS service leverages the DPL instance to provide to the client an abstraction of a highly-available block storage device with unlimited storage space via the scale-out block interface.

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 managing a cloud-based distributed computing environment (CBDCE) that comprises multiple geographically-distributed compute nodes. Multiple services simultaneously execute on the CBDCE compute nodes, with each service comprising multiple service instances that simultaneously execute on multiple distinct compute nodes of the CBDCE. During operation, the system uses a distributed database to track the status of the CBDCE to ensure the ongoing stability and scalability of the CBDCE. Upon receiving a request that is associated with the configuration of the CBDCE, a service accesses CBDCE status information from the distributed database to respond to the request.

Abstract: The disclosed embodiments disclose techniques for journaling data received in a cloud-based distributed computing environment (CBDCE). Multiple services simultaneously execute on the CBDCE compute nodes, with each service comprising multiple service instances that simultaneously execute on multiple, distinct compute nodes of the CBDCE. The CBDCE includes a distributed database that enables coordination between the service instances of services that execute in the CBDCE; this distributed database also includes multiple distributed database instances that simultaneously executing on multiple different CBDCE compute nodes. During operation, a service instance executing on one of these compute nodes receives a client request. The service instance submits this client request to a distributed database instance and, in parallel, also submits the client request and its associated user data to a distributed journaling service.

Abstract: The disclosed embodiments disclose techniques for managing cloud-based storage using a time-series database. A distributed cloud data management system (DCDMS) manages objects stored in a cloud storage system. The DCDMS leverages a distributed time-series database to track objects accessed via the DCDMS. During operation, the DCDMS receives a request to access an object using a path identifier and an object identifier. The DCDMS determines from the path identifier that the request is associated with one of its supported extended capabilities, and uses the previously tracked object operations that are stored in the time-series database to determine the actual target bucket in the cloud storage system that contains the requested object; the target bucket that contains the object may be different from the bucket identified in the path identifier that is received. The object identifier is then used to access the requested object from the target bucket to service the request.

Abstract: The disclosed embodiments disclose techniques for managing a global namespace for a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in a cloud storage system; the cloud controllers ensure data consistency for the stored data, and each cloud controller caches portions of the distributed filesystem. Furthermore, a global namespace for the distributed filesystem is also split across these cloud controllers, with each cloud controller “owning” (e.g., managing write accesses for) a distinct portion of the global namespace and maintaining a set of namespace mappings that indicate which portion of the namespace is assigned to each cloud controller. During operation, an initial cloud controller receives a request from a client system to access a target file in the distributed system. This initial cloud controller uses the namespace mappings for the global namespace to determine a preferred cloud controller that will handle the request.

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 optimizing caching performance 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 cloud controllers cache portions of the distributed filesystem on hard drives with rotating disk platters. The outside portions of these disk platters have higher I/O bandwidth than the inside portions of the disk platters. During operation, a cloud controller determines that a hot subset of cached data is likely to be accessed frequently by clients, and stores this hot subset to an outside portion of a disk platter. The cloud controller further determines that a cold subset of cache data is less likely to be accessed by clients, and stores the cold subset on an inside portion of a disk platter.

Abstract: The disclosed embodiments disclose techniques for managing opportunistic locks 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 client sending a request to access a file from a cloud controller also requests an opportunistic lock for the file. If there are no other outstanding client accesses on the other cloud controllers that preclude the requested opportunistic lock, the cloud controller grants the client file access and the opportunistic lock.

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 facilitating access to a remote cloud service via a cloud controller for 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 detects a request from a co-located client to access a network address that is in the same subnet of their local network. The cloud controller determines that the network address is associated with the remote cloud service (which executes in a cloud storage environment) and forwards the request to the remote cloud service.

Abstract: The disclosed embodiments disclose techniques for managing a global namespace for a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in a cloud storage system; the cloud controllers ensure data consistency for the stored data, and each cloud controller caches portions of the distributed filesystem. Furthermore, a global namespace for the distributed filesystem is also split across these cloud controllers, with each cloud controller “owning” (e.g., managing write accesses for) a distinct portion of the global namespace and maintaining a set of namespace mappings that indicate which portion of the namespace is assigned to each cloud controller. During operation, an initial cloud controller receives a request from a client system to access a target file in the distributed system. This initial cloud controller uses the namespace mappings for the global namespace to determine a preferred cloud controller that will handle the request.

Abstract: The disclosed embodiments disclose techniques that facilitate of avoiding client timeouts in a distributed filesystem. Multiple 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 in a local storage pool. During operation, a cloud controller receives from a client system a request for a data block in a target file that is stored in the distributed filesystem. Although the cloud controller is already caching the requested data block, the cloud controller delays transmission of the cached data block; this additional delay gives the cloud controller more time to access uncached data blocks for the target file from a cloud storage system, thereby ensuring that subsequent requests of such data blocks do not exceed a timeout interval on the client system.

Abstract: 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.

Abstract: The disclosed embodiments provide a system that uses overlay metadata in a cloud controller to generate incremental snapshots for a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more cloud storage systems. More specifically, the cloud controllers cache and ensure data consistency for the data stored in the cloud storage systems, with each cloud controller maintaining a metadata hierarchy that reflects the current state of the distributed filesystem. During operation, a cloud controller receiving new data from a client: (1) stores the new data in the cloud controller; (2) creates a metadata entry for the new data in the locally maintained metadata hierarchy; (3) updates the overlay metadata to point to the metadata entry and the new data stored in the cloud controller; and (4) then uses the overlay metadata to generate an incremental snapshot for the new data.

Abstract: The disclosed embodiments disclose techniques for executing a cloud command 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 presents a distributed-filesystem-specific capability to a client system as a file in the distributed filesystem (e.g., using a file abstraction). Upon receiving a request from the client system to access and/or operate upon this file, the client controller executes an associated cloud command. More specifically, the cloud controller initiates a specially-defined operation that accesses additional functionality for the distributed filesystem that exceeds the scope of individual reads and writes to a typical data file.

Abstract: The disclosed embodiments disclose techniques that facilitate the process of performing anti-virus checks 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 write request from a client system that seeks to store a target file in the distributed system. A scan is then performed for this target file. For instance, the scan may be an anti-virus scan that ensures that viruses are not spread to the distributed filesystem or the clients of the distributed filesystem.

Abstract: The disclosed embodiments disclose techniques for restoring an archived file in 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. Furthermore, cloud controllers may archive infrequently-accessed files in an archival cloud storage system. During operation, a cloud controller receives a request from a client system to access an archived file, and restores this archived file from the archival cloud storage system.

Abstract: The disclosed embodiments disclose techniques for synchronizing file updates between two cloud controllers of 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 a request from a client to access a file in the distributed filesystem. The cloud controller sends a synchronization update request for the file to a second cloud controller and in response receives a synchronization update for the file from the second cloud controller.