Hewlett-Packard Development Company, L.p.

Hewlett Packard Enterprise Development LP

Wojciech Golab

Mehul A Shah

Alan Hersh Karp

Nathan Lorenzo Binkert

Dhruva Ranjan Chakrabarti

Terence Patrick Kelly

Indrajit Roy

Goetz Graefe

Harumi Kuno

Matthew D Pickett

Marcos Kawazoe Aguilera

Xiaozhou Li

Benjamin Albert Sowell

Stavros Harizopoulos

John Johnson Wylie

An embodiment provides a system and method for transaction commitment and replication. The method includes receiving a minitransaction from a client node at one or more memory nodes, wherein each memory node includes a number of replicas. The minitransaction is a type of transaction which atomically executes any combination of reading, comparing, and writing to any of a number of memory locations. The method also includes determining, for a leader of the replicas within a memory node, whether the leader is able to commit the minitransaction and stabilizing state changes of the minitransaction within a transaction log using a consensus procedure to update the replicas. The method further includes committing the minitransaction if, at each memory node, a quorum of the replicas is able to stabilize the minitransaction, or aborting the minitransaction otherwise.

Transaction commitment and replication in a storage system

A shiftable memory supporting atomic operation employs built-in shifting capability to shift a contiguous subset of data from a first location to a second location within memory during an atomic operation. The shiftable memory includes the memory to store data. The memory has the built-in shifting capability. The shiftable memory further includes an atomic primitive defined on the memory to operate on the contiguous subset.

Shiftable memory supporting atomic operation

A system includes an initiator and processing nodes. The initiator distributes portions of a transaction among the processing nodes. Each processing node has at least one downstream neighbor to which the processing node sends commit messages. The commit messages include a commit status of the processing node. The downstream neighbor is also a processing node.

Distributed transaction processing through commit messages sent to a downstream neighbor

Based on events corresponding to operations performed with respect to a data store, a measure is computed that represents an instantaneous consistency level, at a point in time, of data that is subject to the operations.

Providing a measure representing an instantaneous data consistency level

To access data, a distributed balanced tree having nodes distributed across plural servers is accessed. Version information is associated with the nodes of the distributed balanced tree. During an operation that accesses the distributed balanced tree, the version information is checked to determine whether content of one or more nodes of the distributed balanced tree has changed during the operation.

Providing a distributed balanced tree across plural servers

In one example, a method for implementing recovery segments includes sending an application message from a parent process executed by a first computing device to a child process executed by a second computing device and identifying a dependency created by the application message. This identified dependency is included in a dependence set of the child process and saved. A checkpoint is generated by the parent process and a checkpoint message that includes dependency information is sent from the parent process to the child process. The child process modifies the dependence set according to the dependency information and generates a second checkpoint that is saved in nonvolatile memory of the second computing device. Upon occurrence of a failure of the parent process, the child process reverts to a most recent checkpoint generated by the child process that does not include the effects of processing an orphan message.

Recovery segments

A distributed balanced tree having a plurality of nodes distributed across a plurality of servers is accessed. Version information associated with a node of the distributed balanced tree is retrieved. Validity of a lookup transaction performed on the balanced tree is determined by verifying a version value of only the leaf node accessed during the lookup operation against the retrieved version information.

Validation of distributed balanced trees

A computer apparatus and related method to reduce database congestion is provided. In one aspect, the computer apparatus and method may generate a new partition within a hierarchical data structure of interlinked nodes, if a distribution of key values stored in the hierarchical data structure is skewed in favor of a range of key values.

Distribution of key values

A method for verifying a consistency level in a key-value store, in which a value is stored in a cloud-based storage system comprising a read/write register identified by a key. At a centralized monitor node, a history of operations including writes and reads performed at the key is created, and a distance between a read of a value at the key and a latest write to the key is determined. It can then be ascertained whether the distance satisfies a relaxed atomicity property.

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Mountain View, CA, United States of America

Wojciech Golab