Netapp, Inc.

Network Appliance, Inc.

Szu-Wen Kuo

Ananthan Subramanian

Amber M Palekar

J Eric Mowat

Mehul S Shah

Parag Sarfare

Nikhil Mattankot

Asif Imtiyaz Pathan

Santhosh Selvaraj

Stephen Wu

Mardiros Z Chakalian

Yong Cho

Sriram Venketaraman

Brian Mederic Quirion

Kumaran Nagappan

David A Grunwald

Robert M English

Ashish Prakash

Paul Christopher Eastham

Manan Dahyabhai Patel

James J Voll

Kartik Ayyar

Emmanuel Ackaouy

Travis Ryan Grusecki

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.

Techniques for asynchronous snapshot invalidation

Failover methods and systems for a networked storage environment are provided. In one aspect, a read request associated with a first storage object is received, during a replay of entries of a log stored in a non-volatile memory of a second storage node for a failover operation initiated in response to a failure at a first storage node. The second storage node operates as a partner node of the first storage node. The read request is processed using a filtering data structure that is generated from the log prior to the replay and identifies each log entry. The read request is processed when the log does not have an entry associated with the read request, and when the filtering data structure includes an entry associated with the read request, the requested data is located at the non-volatile memory.

Network storage failover systems and associated methods

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.

Metadata compaction

Failover methods and systems for a networked storage environment are provided. A filtering data structure and a metadata data structure are generated before starting a replay of a log stored in a non-volatile memory of a second storage node, during a failover operation initiated in response to a failure at a first storage node. The second storage node operates as a partner node of the first storage node to mirror at the log one or more write requests received by the first storage node prior to the failure, and data associated with the one or more write requests. The filtering data structure identifies each log entry and the metadata structure stores a metadata attribute of each log entry. The filtering data structure and the metadata structure are used for providing access to a logical storage object during the log replay from the second storage node.

Failover methods and systems for a networked storage environment are provided. A metadata data structure is generated, before starting a replay of entries at a log stored in a non-volatile memory of a second storage node, during a failover operation initiated in response to a failure at a first storage node. The second storage node operates as a partner node of the first storage node, and the metadata structure stores a metadata attribute of each log entry. Furthermore, the metadata attribute of each log entry is persistently stored. The persistently stored metadata attribute is used to respond to a read request received during the replay by the second storage node, while a write request metadata attribute of a write request is used for executing the write request received by the second storage node during the replay.

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.

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.

System and method for invalidation walk-through of inodes

System and method for deferring invalidation of inodes of a volume during volume invalidation

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.

Proximity based lossless compression of client information in a network device

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.

Apparatus and method for data consistency in a proxy cache

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.

Growing community of inventors

Milpitas, CA, United States of America

Szu-Wen Kuo