公开(公告)号：US11934356B2

公开(公告)日：2024-03-19

申请号：US17708312

申请日：2022-03-30

Applicant: Commvault Systems, Inc.

Inventor： Avinash Lakshman ,  Lasaro Camargos ,  Deepak Jain

IPC: G06F7/00 ,  G06F11/14 ,  G06F16/13 ,  G06F16/178 ,  G06F16/2457 ,  G06F16/2458 ,  G06F17/00 ,  G06F16/182 ,  G06F16/27

CPC classification number: G06F16/178 ,  G06F11/1464 ,  G06F16/137 ,  G06F16/24573 ,  G06F16/2471 ,  G06F16/182 ,  G06F16/275

Abstract: A client machine writes to and reads from a virtual disk on a remote storage platform. Metadata is generated and stored in replicas on different metadata nodes of the storage platform. A modified log-structured merge tree is used to store and compact string-sorted tables of metadata. During file storage and compaction, a consistent file identification scheme is used across all metadata nodes. A fingerprint file is calculated for each SST (metadata) file on disk that includes hash values corresponding to regions of the SST file. To synchronize, the fingerprint files of two SST files are compared, and if any hash values are missing from a fingerprint file, then the key-value-timestamp triples corresponding to these missing hash values are sent to the SST file that is missing them. The SST file is compacted with the missing triples to create a new version of the SST file. The synchronization is bi-directional.

公开(公告)号：US11570243B2

公开(公告)日：2023-01-31

申请号：US17465691

申请日：2021-09-02

Applicant: Commvault Systems, Inc.

Inventor： Lásaro Camargos ,  Deepak Jain ,  Avinash Lakshman ,  Bharat Pundalik Naik

IPC: G06F16/182 ,  G06F16/23 ,  H04L67/104 ,  G06F9/455 ,  G06F11/14

Abstract: In a running distributed data storage system that actively processes I/Os, metadata nodes are commissioned and decommissioned without taking down the storage system and without introducing interruptions to metadata or payload data I/O. The inflow of reads and writes continues without interruption even while new metadata nodes are in the process of being added and/or removed and the strong consistency of the system is guaranteed. Commissioning and decommissioning nodes within the running system enables streamlined replacement of permanently failed nodes and advantageously enables the system to adapt elastically to workload changes. An illustrative distributed barrier logic (the “view change barrier”) controls a multi-state process that controls a coordinated step-wise progression of the metadata nodes from an old view to a new normal. Rules for I/O handling govern each state until the state machine loop has been traversed and the system reaches its new normal.