Nutanix, Inc.

Netapp, Inc.

Pete Wyckoff

Niranjan Sanjiv Pendharkar

Alok Nemchand Kataria

Tabrez Parvez Memon

Shubham Shukla

Rishi Bhardwaj

Rohit Jain

Collin Park

Trond Myklebust

A technique improves implementation of an index for an operations log (oplog) that coalesces random write operations directed to a virtual disk (vdisk) stored on an extent store. The oplog temporarily caches data associated with the random write operations (i.e., write data) as well as metadata describing the write data. The metadata includes descriptors to the write data stored on virtual address regions, i.e., offset ranges, of the vdisk and are used to identify the offset ranges of write data for the vdisk that are cached in the oplog. To facilitate fast lookup operations of the offset ranges when determining whether write data is cached in the oplog, an oplog index provides a state of the latest data for offset ranges of the vdisk. The technique improves implementation of the oplog index by storing the oplog index in storage class memory, such as persistent memory, to obviate failure and subsequent recovery of the oplog index.

Technique for improving operations log indexing

A technique replicates an index of an operations log (oplog) from a primary node to a secondary node of a cluster in the event of failure. The oplog functions as a staging area to coalesce random write operations directed to a virtual disk (vdisk) stored on a backend storage tier. The oplog temporarily caches write data as well as metadata describing the write data. The metadata includes descriptors to the write data corresponding to offset ranges of the vdisk and are used to identify ranges of write data for the vdisk that are cached in the oplog. To facilitate fast lookup operations of whether write data is cached in the oplog, an oplog index provides a state of the latest data for offset ranges of the vdisk that enables fast failover of metadata used to construct the oplog index in memory without downtime or significant metadata replay.

Technique for replicating oplog index among nodes of a cluster

One or more aspects of the disclosure relate to techniques for accessing a file stored in a clustered computing network, where the file is stored in the clustered computing network in a plurality of related volumes that stem from a particular (e.g., parent) volume. In the method, a request to retrieve the file from the particular volume is received at the client. The client then determines whether the file is stored in a client memory so as to be identified with the particular volume. If the file is not stored in the client memory so as to be identified with the particular volume, then the file is retrieved from a different but related volume.

Client data retrieval in a clustered computing network

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Durham, NC, United States of America

Pete Wyckoff