Vmware, Inc.

Rob T Johnson

Wenguang Wang

Richard Paul Spillane

Kapil Chowksey

Abhishek Gupta

Jorge Guerra Delgado

Srinath Premachandran

Sandeep Rangaswamy

Exemplary methods, apparatuses, and systems include a file system process obtaining locks on a first node and a second node in a tree structure, with the second node being a child node of the first node. The file system process determines a quantity of child nodes of the second. While holding the locks on the first and second nodes, the file system determines whether to proactively split or merge the second node. In response to determining that the quantity of child nodes is within a first range, the file system process splits the second node. If the file system process determines that the quantity of child nodes is within a second range, the file system process merges the second node.

Proactive splitting and merging of nodes in a B-tree

Exemplary methods, apparatuses, and systems include a file system process reading a first node in a tree data structure from a first memory. The first node includes a first approximate membership query data structure ('AMQ'), a first plurality of child pointers, a first plurality of pivot values, and a first buffer. The file system process determines that the first plurality of child pointers exceeds a maximum size. Using a pivot value in the first plurality of pivot values, the file system process splits the first node into a second node and a third node. The file system process uses the pivot value to split the first buffer into a second buffer and a third buffer. Using the pivot value and the first AMQ, the file system process generates a second AMQ and a third AMQ.

Reduced bandwidth queries in B e-trees using approximate membership query data structures

Exemplary methods, apparatuses, and systems include a file system process inserting a first key/value pair and a second key/value pair into a first tree. The second key is a duplicate of the first key and the value of the second key/value pair is an operation changing the value. In response to a request for a range of key/value pairs, the process reads the second key/value pair and inserts it in a second tree. The process reads the first pair and determines, while inserting the first pair in the second tree, that the second key is a duplicate of the first key. The file system process determines an updated value of the first value by applying the operation in the second value to first value. The file system operation updates the second key/value pair in the second tree with the updated value and returns the requested range of key/value pairs.

Range lookup operations for B-trees using update messages

Embodiments of the present disclosure relate to techniques for performing a merge update for a database. In particular, certain embodiments of a method include generating a message comprising a first key and a first transaction associated with the first key, the first transaction indicating a transaction to perform other than for key-value pairs comprising the first key. The method further includes storing the message in a database. The method further includes merging the message with a first key-value pair stored in the database, the first-key value pair comprising the first key. The method further includes performing the first transaction based on merging the message with the first key-value pair.

Merge updates for key value stores

Exemplary methods, apparatuses, and systems include a file system process determining to a flush a node in a first tree. The first node includes a buffer structured as a second tree. The file system process generates an input/output instruction to load the buffer from a first memory to a second memory. The second tree is stored in two more non-contiguous locations in the first memory and the input/output operation includes a read operation corresponding to each of the two or more non-contiguous locations. The file system process causes the input/output instruction to be executed concurrently on the first memory.

Optimizing operations on b e-trees stored on solid state media

Data storage system and method for managing transaction requests to the data storage system utilizes an active write ahead log and a standby write ahead log to apply the transaction requests to a storage data structure stored in a storage system of the data storage system.

Mirrored write ahead logs for data storage system

Data storage system and method for managing transaction requests in the data storage system utilizes prepare requests for a transaction request for multiple data storage operations. The prepare requests are sent to selected destination storage nodes of the data storage system to handle the multiple data storage operations. Each prepare request includes at least one of the multiple data storage operations to be handled by a particular destination data store node and a list of the destination storage nodes involved in the transaction request.

System and method for managing transactions for multiple data store nodes without a central log

Data storage system and method for managing transaction requests to the data storage system utilizes a write ahead log to write transaction requests received at the data storage system during a current checkpoint generation. After the transaction requests in the write ahead log are applied to a copy-on-write (COW) storage data structure stored in a storage system, one of first and second allocation bitmaps is updated to reflect changes in the COW storage data structure with respect to allocation of storage space in the storage system, and one of first and second super blocks is updated with references to central nodes of the COW storage data structure. After the allocation bitmap and the super block have been updated, an end indicator for the current checkpoint generation is written in the write ahead log to indicate that processing of the transaction requests for the current checkpoint generation has been completed.

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Palo Alto, CA, United States of America

Rob T Johnson