Seagate Technology Incorporated

Oracle America, Inc.

Nikita Danilov

Nathaniel Rutman

John Michael Bent

Hua Yin Huang

Kenneth K Claffey

Eric Barton

Nachiket Shrikant Sahasrabudhe

Raj Bahadur Das

Peter Braam

Yuriy Umanets

Mandar Satish Sawant

A system includes multiple nodes that communicate among one another. Each of the multiple nodes includes at least one data storage container. The system also includes a sender sliding window (SSW) that controls sending of data from at least one node of the multiple nodes to at least one other node of the multiple nodes. The system further includes a receiver sliding window (RSW) that controls receiving of the data from the at least one node of the multiple nodes at the at least one other node of the multiple nodes. At least one of the SSW or the RSW is sharable amongst more than one node of the multiple nodes.

Sliding window protocol for communication among more than two participants

A composite layout to store one or more extents of a data object in a first storage system and one or more extents of the data object in a second, different storage system. The first storage system may be configured for the efficient storage of small chunks of data such as, e.g., chunks of data small than the addressable block size of the storage devices used by the storage systems.

Data storage layouts

Systems, apparatus, and methods for data distribution within a failure domain tree are described herein. Data objects may be distributed uniformly into symmetric failure domain trees. Asymmetric failure domain trees may be used to generate symmetric failure domain trees. The systems, apparatus, and methods may distribute a data object to attempt to satisfy the failure tolerance level of as many failure domain levels of the symmetric failure domain trees as possible.

Data distribution within a failure domain tree

A system including a plurality of nodes. Each node includes a pending operations list, an unstable operations list, and a hardware controller. The pending operations list can include operations that have not yet been executed on the node. The unstable operations list can include operations that have not yet been stored on non-volatile data storage. Each of the operations listed in the unstable operations list can include a listing of all other operations that must be executed prior to the operation being executed on each respective node. The hardware controller can be configured to execute at least one operation listed in the pending operations list, remove at least one executed operation from the pending operations list, and remove at least one operation from the unstable operations list.

Node management of pending and unstable operations

A composite layout including a plurality of ranked sub-layouts may be used to provide various functionality for data object look-up and file system activities. Each sub-layout may include mapping information linking one or more extents of a data object to one or more locations on one or more storage apparatuses. Generally, mapping information in the highest priority sub-layout including mapped extents may be used during 'reads' while the highest priority sub-layout may be used for 'writes.'

Data storage composite layouts for data objects

A system utilizing elastic spares includes nodes and devices to store one or more data objects having information. The data object includes data object units each assigned to a storage location on a different node than the other units. The data object includes one or more spare units to store reconstructed information of a failed unit. When one of the data objects has a failed unit and no spare units available to store reconstructed information, a controller of the system assigns an elastic spare unit to an available storage location of one of the nodes. Reconstructed information of the failed unit is stored in the elastic spare unit.

Data storage systems using elastic spares

A method of replicating a source file system on a storage system, the method including: utilising a changelog operable to store sequentially a data record corresponding to a modification of a source file system by a storage request; specifying a first data record of the changelog at a first time; initiating a scan of the directory inodes of the source file system at the first time; scanning the directory inodes; completing the scan at a second time later than the first time; specifying a second data record of the changelog at the second time; storing, in a database, information corresponding to the scanned directory inodes; updating the database with sequential data records from the first data record to the second data record of the changelog; and building, on a computer system, a replica target file system based on the database.

Method of, and apparatus for, file system replication

In distributed state systems, server nodes can receive operation requests from multiple clients. When a server node executes an operation request, the server node can store an indicator of the operation request to a log of operations and send a reply message to the requesting client. The reply message can include a reply log having a list of N executed operation requests. If the server needs rebuilding, any operations not already stored to the server node log may be lost. The server can rebuild lost operations of a file system by receiving the reply logs or indicators of the operations therein from one or more clients.

Multiple concurrent in-flight replies in a distributed state system

A method for performing distributed transactions of a cluster. The method includes, in response to a lock request including a first epoch from a first node, setting a local epoch to a maximum of the first epoch and the local epoch, sending a first lock including the local epoch to the first node, and in response to a conflicting lock request including a second epoch from a second node, setting the local epoch to a maximum of the second epoch and the local epoch, where the conflicting lock request is delayed until after the first lock is released. The method further includes, in response to a reintegration request including a third epoch from the first node, setting the local epoch to a maximum of the third epoch and the local epoch and performing a reintegration based on the reintegration request, where the reintegration is logged using the local epoch.

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Moscow, Russia

Nikita Danilov