Microsoft Technology Licensing, LLC

Microsoft Corporation

Robert P Fitzgerald

Cristian Diaconu

Per-Ake Larson

Richard F Rashid

William J Bolosky

Steven P Levi

Michael James Zwilling

Craig M Dowell

Jan De Rie

John R Douceur

John W Miller

Michael B Jones

Joseph S Barrera, Iii

Paul J Leach

Bruce Lee Worthington

Qi Zhang

Ruston Panabaker

Richard Powell Draves, Jr

Richard P Draves

Stuart Sechrest

Jason Carl Hendrickson

Changjiu Xian

Nathan P Myhrvold

James Robert Hamilton

William Jefferson Westerinen

Cenk Ergan

Michael Richard Fortin

Avi R Geiger

John Mark Miller

Alexander Kirshenbaum

James Charles Kleewein

Lawrence William Osterman

Matthew Robert Ayers

Charles T Lenzmeier

Aaron Edward Dietrich

René A Vega

Swaroop Kavalanekar

Garth A Gibson

Joseph S Barrera

A versioned records management computing system that uses a restart era in order to promote rapid recovery. A persistent store includes a multi-versioned record collection. The records are also associated with a restart era that corresponds to the era of operation of the computing system after a restart. Upon a recovery, the current restart era changes. An object collection media has an object collection that conforms to an object model such that the object model is used to operate upon the records. The object collection media is operable such that the object collection is durable so as to survive restarts of the system to thereby allow for accelerated recovery.

Versioned records management using restart era

A versioned records management system that uses a restart era in order to promote rapid recovery. A persistent store includes a plurality of items that are each marked with a restart era. Any item that was created in the current restart era is marked with the current restart era. The persistent store also includes a first subset of the items comprising a plurality of records. At least one record includes multiple corresponding versions. The persistent store also includes a second subset of the items comprising a collection of objects that conform to an object model that is used to operate upon the plurality of records via the object collection. The versioned records management system recovers from a crash by promoting an item in the persistent store to the current restart era, in parallel with normal operation of the versioned records management system.

A log manager causing events to be written to the primary and the secondary computing systems for high availability, and returning threads quickly. Rather than cause every event write to be immediately written to the secondary computing system, the log management component is triggered to write to the secondary computing system upon detecting event write requests of event writes of a particular event type. In response to detecting such an event write, the log management component gathers a group of event writes corresponding to that particular event write, and dispatches the event writes as a group. The particular thread that initiated the particular event write of the particular event type is returned after dispatching the event write group, but before or without confirmation of the particular event write group has been written to the secondary computing system.

Early thread return with secondary event writes

The recovery of one or more transactions in a computing system in which one or more persistent systems are coupled via a bus to one or more processors. As an example, the persistent system may serve as at least part of the main memory of the computing system. The transaction might implement multi-versioning in which a record is not updated in place. Rather, each record is represented as a sequence of one or more record versions, each version having a valid interval during which the record version is considered to properly represent the record.

Recovery processing for database in persistent system

A system that uses a persistent main memory to preserve events that await logging in a persistent store. Each event is written into the persistent main memory so as to be loggable in case of recovery. For instance, the event may be written into a log cache structure, along with other state which identifies that the event is in the particular log cache structure, the location of the event within the particular log cache structure, and the order of the event. To recover, the log in the persistent store is evaluated to identify the end of the stored log. The tail of the log is identified in the persistent main memory by identifying any log cache structures that are after the end of the stored log and which are validly recoverable. The log cache structure contents are then serialized one log cache at a time, earliest first.

Tail of logs in persistent main memory

Performing a transaction in the context of a computing system that has one or more persistent systems coupled to one or more processors over a bus. As an example, the persistent system may serve as at least part of the main memory of the computing system. The transaction might implement multi-versioning in which a record is not updated in place. Rather, each record is represented as a sequence of one or more record versions, each version having a valid interval during which the record version is considered to properly represent the record. The transaction processing uses torn write detection so that recovery processes may use such guards to verify that there are no torn writes. For instance, torn write guards may be used to verify the integrity of record versions as well as the log buffers that refer to the record versions.

Transaction processing using torn write detection

The efficient use of threads that issue calls to log events. While waiting for the call to return or complete, the threads are put to work on other tasks that are not part of the process that generated the event. This can occur without context switching of the thread, especially when the task to be performed is state-less or context free. In the efficient thread diversion process, the thread calls a logging component to log an event. This blocks the thread from continuing work on a process that the event is part of until the event is logged. The thread then performs a diversion task that is not part of the processing unit that the event is part of. After detecting that the event has logged, the thread continues work on the processing unit that the event is part of.

Thread diversion awaiting log call return

A method and an apparatus for characterizing performance of a device based on user-perceivable latency. To characterize device performance, a value of a metric may be computed from latencies of operations performed by the device. In computing a value of a metric, latencies may be treated differently, such that some latencies perceivable by a user of the device may have a greater impact on the value of the metric than other latencies that either are not perceivable or are perceived by the user to a lesser degree. Such a performance metric based on user-perceivable latency facilitates identification of computing device that provide a desirable user experience.

Characterizing device performance based on user-perceivable latency

The recovery of a transaction, and perhaps the recovery of multiple transactions, in a computing system in which one or more persistent systems are coupled via a bus to one or more processors. As an example, the persistent system may serve as part of the main memory of the computing system. The transaction might implement multi-versioning in which a record is not updated in place. Rather, each record is represented as a sequence of one or more record versions, each version having a valid interval during which that the record version is considered to properly represent the record. Torn write guards may be used to verify that there are no torn writes in the record versions or in the log buffer associated with the transaction.

Recovery processing using torn write detection

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Robert P Fitzgerald