Microsoft Technology Licensing, LLC

Manish Chablani

Ju Wang

Shane Kumar Mainali

Krishnan Varadarajan

Jegan Devaraju

Quan Zhang

Hao Feng

Sridhar Srinivasan

Rene Antonio Vega

Shuvabrata Ganguly

Venkates Paramasivam Balakrishnan

Zichen Sun

Andrew Ernest Nicholas

Ellsworth Davis Walker

Shaoyu Zhang

He Su

Kaifeng Zhu

Jianwu Gao

Bin Tong

Bradley Gene Calder

Aaron William Ogus

Andrew James Edwards

Yikang Xu

Muhammad Junaid Shahid

Pradeep Seela

Ziehen Sun

Jegan Devanraju

A distributed storage system includes table controllers collectively storing partitions of a logical table having multiple rows. For each of the partitions, a corresponding table controller stores a subset of the rows of the logical table across individual pages. A management controller updates a schema of the logical table from a first to a second schema definition by, for each of the partitions, sending an update command indicating the second schema definition to the corresponding table controller. The first table controller corresponds to a first partition that includes a first subset of the rows. The first table controller, prior to receiving the update command, includes an identifier of the first schema definition within each page of data for the first subset. Subsequent to receiving the update command, the first table controller, when writing each new page of data for the first subset, includes an identifier of the second schema definition.

Online schema change of range-partitioned index in a distributed storage system

Anchor tree cross-merge within a distributed storage system. A computer system identifies a data structure that includes (i) a root anchor tree and (ii) an ordered set of anchor trees that are ordered based on their creation, such that a last anchor tree of the ordered set of anchor trees is most-recently created. The data structure stores index data for a set of objects stored in a non-volatile storage. The computer system creates a new anchor tree in the ordered set of anchor trees. The computer system identifies, from a set of delta tables, index data representing one or more objects that are stored on the non-volatile storage. The computer system merges the index data representing the one or more objects into the new anchor tree.

Staging anchor trees for improved concurrency and performance in page range index management

A distributed storage system includes non-volatile storage storing portions of a first object. The first object encompasses data having a first range of addresses and each portion includes data for a respective range of addresses that is a proper subset of the first range. A first data structure stores, for each portion, data indicating the respective range of addresses and a pointer to where the portion is stored. The first data structure includes a root tree and a set of trees ordered by creation data such that a last tree is most-recently created. The non-volatile storage stores received write data and a write buffer stores index data pointing to storage locations of the received write data. An index management system stores the index data from the write buffer into the last tree and, if the ordered set is empty, creates a tree in the ordered set before the storing.

Embodiments provide a method to collect aggregate information or usage data quickly and efficiently with minimal lag. Additionally, the system can use this aggregate information internally for improved load balancing, better data placement, optimization, and enhanced debugging. The system can quickly look at aggregate information across a huge amount of data and drill down cheaply because the aggregate information is generated using existing processes. Aggregated statistics storage and collection may be built on top of an LSM tree used to store a persistent index for a cloud storage system. The statistics may also represent the result of an operation (e.g., max, min, sum, average) on selected parameter(s) or attribute(s) of stored data. Aggregate statistics values may be efficiently maintained during index merge and garbage collection processes or any other index management. As delta LSM trees are merged into a base LSM tree, the aggregates are updated in delta fashion.

File table index aggregate statistics

One or more virtual processors can be added or removed from a virtual machine based on CPU pressure measured within the virtual machine. In addition to the foregoing, CPU pressure can also be used to determine whether to remove a virtual processor from a virtual machine, which may cause the computer system to consume less power. In the alternative, virtual processors can be parked and/or unparked in order to reduce the amount of power consumed by the virtual machine. In addition, virtual processors can be forcibly parked during a migration operation.

Virtual processor allocation techniques

In various embodiments, methods and systems for implementing multiple transaction logs in a distributed storage system are provided. A log stream component detects performance metrics of a plurality of log streams. The performance metrics are associated with requests from partitions in the distributed storage system. A transaction component receives a request to execute a transaction using a log stream. The request is received from a partition of the distributed storage system. The performance metrics of the plurality of log streams can be referenced, where the performance metrics indicate a performance capacity of a selected log stream to process the request. A log stream for executing the transaction is determined based on the performance capacity. The log stream selected can also factor request attributes of the request. The transaction component communicates the request to be executed, using the log stream to perform the transaction.

Multiple transaction logs in a distributed storage system

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Manish Chablani