Abstract: Asynchronous snapshot invalidation techniques are described. According to various such techniques, an enhanced file handle structure may be defined that includes a snapshot generation ID that is to comprise a value that singularly identifies a snapshot performed at a particular point in time. In some embodiments, when a snapshot ID assigned to that snapshot is reused at a subsequent point in time, a different snapshot generation ID may be assigned to that subsequent snapshot. With respect to an in-core cache, the differing snapshot generation IDs may eliminate unacceptable ambiguity regarding respective file information sets corresponding to the initial and subsequent snapshots sharing the same snapshot ID. As a result, obsolete file information sets may be cleared from the in-core cache asynchronously, enabling improved performance. The embodiments are not limited in this context.

Abstract: Techniques are provided for compacting indirect blocks. For example, an object is represented as a structure comprising data blocks within which data of the object is stored and indirect blocks comprising block numbers of where the data blocks are located in storage. Block numbers within a set of indirect blocks are compacted into a compacted indirect block comprising a base block number, a count of additional block numbers after the base block number in the compacted indirect block, and a pattern of the block numbers in the compacted indirect block. The compacted indirect block is stored into memory for processing access operations to the object. Storing compacted indirect blocks into memory allows for more block numbers to be stored within memory.

Abstract: Techniques are provided for compacting indirect blocks. For example, an object is represented as a structure comprising data blocks within which data of the object is stored and indirect blocks comprising block numbers of where the data blocks are located in storage. Block numbers within a set of indirect blocks are compacted into a compacted indirect block comprising a base block number, a count of additional block numbers after the base block number in the compacted indirect block, and a pattern of the block numbers in the compacted indirect block. The compacted indirect block is stored into memory for processing access operations to the object. Storing compacted indirect blocks into memory allows for more block numbers to be stored within memory. This improves the processing of access operations because reading the block numbers from memory is faster than loading the block numbers from disk.

Abstract: Asynchronous snapshot invalidation techniques are described. According to various such techniques, an enhanced file handle structure may be defined that includes a snapshot generation ID that is to comprise a value that singularly identifies a snapshot performed at a particular point in time. In some embodiments, when a snapshot ID assigned to that snapshot is reused at a subsequent point in time, a different snapshot generation ID may be assigned to that subsequent snapshot. With respect to an in-core cache, the differing snapshot generation IDs may eliminate unacceptable ambiguity regarding respective file information sets corresponding to the initial and subsequent snapshots sharing the same snapshot ID. As a result, obsolete file information sets may be cleared from the in-core cache asynchronously, enabling improved performance. The embodiments are not limited in this context.

Abstract: Asynchronous snapshot invalidation techniques are described. According to various such techniques, an enhanced file handle structure may be defined that includes a snapshot generation ID that is to comprise a value that singularly identifies a snapshot performed at a particular point in time. In some embodiments, when a snapshot ID assigned to that snapshot is reused at a subsequent point in time, a different snapshot generation ID may be assigned to that subsequent snapshot. With respect to an in-core cache, the differing snapshot generation IDs may eliminate unacceptable ambiguity regarding respective file information sets corresponding to the initial and subsequent snapshots sharing the same snapshot ID. As a result, obsolete file information sets may be cleared from the in-core cache asynchronously, enabling improved performance. The embodiments are not limited in this context.

Abstract: A system and method for deferring an invalidation walk-through of a volume in memory and a later invalidation walk-through of inodes the volume are described herein. Node A may store volume information for one or more volumes to memory including inodes of the volume storing data for the volume. Node A performs a primary procedure that may include removing volumes from the memory, such as a procedure that transfers ownership of the volumes to node B. Removing a volume from memory comprises removing its volume information from memory. Node A performs an invalidation deferment procedure that marks each volume as stale for preventing data of the volumes to be served and sends a completion message to node B which begins serving data of the volume. After node B begins serving data of the volume, node A performs an invalidation walk-through procedure to remove inodes of the volume from memory.

Abstract: A system and method for deferring an invalidation walk-through of a volume in memory and a later invalidation walk-through of inodes the volume are described herein. Node A may store volume information for one or more volumes to memory including inodes of the volume storing data for the volume. Node A performs a primary procedure that may include removing volumes from the memory, such as a procedure that transfers ownership of the volumes to node B. Removing a volume from memory comprises removing its volume information from memory. Node A performs an invalidation deferment procedure that marks each volume as stale for preventing data of the volumes to be served and sends a completion message to node B which begins serving data of the volume. After node B begins serving data of the volume, node A performs an invalidation walk-through procedure to remove inodes of the volume from memory.

Abstract: Information representing a plurality of clients on a network is stored in a data structure. The data structure may be stored within a server or agent in a content delivery network and may include client network address information. The data structure is dynamically compressed based on network proximity information relating to the clients.

Abstract: A system and method for maintaining multiple inode containers is used to manage file system objects in a single logical volume of a network storage server. The system provides multiple inode containers to store metadata for file system objects in the logical volume. The system may use a first inode container to store private inodes used by the storage server and a second inode container to store public inodes that are useable by clients of the storage server. During a replication process, a source storage server generates a set of replication operations based on inodes in the public inode container and excluding inodes in the private inode container. In a destination server implementing multiple inode containers, the server generates inodes based on the replication operations and stores the inodes in the public inode container. These new inodes are stored in the public inode container with the same inode number or identifier as the corresponding inode on the source storage server.

Abstract: In an embodiment, a method to provide data consistency in a storage system, includes: providing, by a server to a proxy cache, a lock associated with a delegated file in the server; in response to a write request from a client, modifying data in a cached copy of the delegated file in the proxy cache; revoking, by the server, the lock associated with the delegated file, in response to a request from another device to access the delegated file so that the delegated file is now a formerly delegated file; and writing the modified data to the formerly delegated file in the server to update the formerly delegated file; and permitting access to the formerly delegated file by the another device.

Abstract: Information representing a plurality of clients on a network is stored in a data structure. The data structure may be stored within a server or agent in a content delivery network and may include client network address information. The data structure is dynamically compressed based on network proximity information relating to the clients.

Abstract: A method and apparatus for a rumor based protocol for distributed state synchronization between request routing servers have been described. State synchronization is maintained between routing servers via agents that respond with information requested by the servers.

Abstract: The invention includes a method for selecting a replicated node from a domain of replicated nodes in a computer network. The method comprises maintaining a list of the replicated nodes; receiving a name resolution request to resolve a name for the domain into a network address; selecting one of the replicated nodes based on predefined selection criteria and in response to the name resolution request; and sending a network address of the selected replicated node to a network address associated with the name resolution request.

Abstract: A method and apparatus for estimating relative network proximity between request routing agents and client agents are described herein. In one embodiment, the method includes a proximity estimation unit to send a first number of probe messages to a client agent without waiting to receive a reply message, wherein the proximity estimation unit is to receive a first set of reply messages. The apparatus also including a proximity verification unit coupled with the proximity estimation unit, to send a second number of probe messages to the client agent, and to receive a second set of reply messages.

Abstract: The invention provides for managing information for multiple devices. Each of a set of devices retrieves information from a sequence of servers. A device when starting up reads a list of file names, reads information from each file in sequence, and resolves conflicts among files to present a consistent configuration on each restart of each device. A file includes a sequence of <name, value> pairs. In those cases when two variables have the same name, an operator associated with the second pair indicates whether to overwrite the first value or to edit the first value, such as by appending the second value. One of the pairs indicates the list of file names itself. When the list of file names is changed, the device for which the change is made re-reads the sequence of files and repeats its determination of the pairs, until the list of file names is stabilized.