公开(公告)号：US11288112B1

公开(公告)日：2022-03-29

申请号：US16587777

申请日：2019-09-30

Applicant: Amazon Technologies, Inc.

Inventor： Ramesh Shankar ,  Murali Brahmadesam ,  Raman Mittal ,  Grant Alexander MacDonald McAlister ,  Minsoo Oh ,  Yi Wen Wong

IPC: G06F11/07 ,  G06F11/20

Abstract: Data loss thresholds are enforced when performing updates to mirrored data sets. When an update is received for a data set that is mirrored to other copies of the data set, an evaluation of the difference between the data set and the other copies of the data set may be performed. If the evaluation determines that the difference fails to satisfy a threshold for acceptable data loss at the other copies upon a failure of the data set, a data loss mitigation action may be applied to performance of the update until the difference satisfies the threshold.

公开(公告)号：US12242505B1

公开(公告)日：2025-03-04

申请号：US18194568

申请日：2023-03-31

Applicant: Amazon Technologies, Inc.

Inventor： Ramesh Shankar ,  Raman Mittal ,  Minsoo Oh ,  Andrew Willis Callahan

IPC: G06F16/27

Abstract: Interruptions in an ordered replication stream can be received from in a database. A database instance of the ordered replication stream may detect missing log records and then evaluate log records that are subsequently received to determine whether to update a portion of an in-memory data structure for performing database requests using a comparison of sequence numbers of the last update corresponding to the portion of the in-memory data structure indicated in the log record and the last update recorded for the portion of the in-memory data structure. For comparison indicating valid portions, the log record can be used and for comparison indicating invalid portions, the portion of the in-memory data structure can be made unavailable.

公开(公告)号：US11144407B1

公开(公告)日：2021-10-12

申请号：US16588868

申请日：2019-09-30

Applicant: Amazon Technologies, Inc.

Inventor： Ramesh Shankar ,  Murali Brahmadesam ,  Raman Mittal

IPC: G06F11/00 ,  G06F11/14 ,  G06F16/27

Abstract: Systems and methods are disclosed to implement a synchronous database mirroring technique using delayed visibility write operations. In embodiments, a durable log of write operations in a primary database is replicated to a secondary database. The two databases do not make corresponding operations durable in a synchronous manner. However, the two databases coordinate to provide a visible view of the two durable logs that is guaranteed be durable in both databases. In embodiments, the primary database may monitor the state of the durable log of the secondary database, and periodically update the visible range of the logs to include operations that have been made durable in both databases. Advantageously, the visible range of the logs is permitted to grow asynchronously from the logs themselves, so that the two databases can provide a synchronized visible view of the log data without placing timing constrains on the data's durability.

公开(公告)号：US12038946B1

公开(公告)日：2024-07-16

申请号：US18194579

申请日：2023-03-31

Applicant: Amazon Technologies, Inc.

Inventor： Ramesh Shankar ,  Raman Mittal

IPC: G06F16/23 ,  G06F16/27

CPC classification number: G06F16/27 ,  G06F16/2329

Abstract: Connection loss may be minimized for performing database query engine changes. A distributed database system may include different instances of the query engine that provide access to a database. When an event to change the version of the query engine is detected, a copy of the database may be created and a new instance of the query engine created. Read-only access to the database may be maintained using the different instances of the query engine while the new instance may be upgraded to the different version of the query engine. Upon successful installation of the different version of the query engine at the new instance, the new instance may be given read-write access to the database using the copy of the database and other database instances may be upgraded to the different version of the query engine.

公开(公告)号：US10929428B1

公开(公告)日：2021-02-23

申请号：US15918989

申请日：2018-03-12

Applicant: Amazon Technologies, Inc.

Inventor： Murali Brahmadesam ,  Seungmin Wei ,  Sumit Kumar ,  Raman Mittal ,  Crosbie Matthew Smith ,  Kevin Liu ,  Aadithya Chandramalle Gowda ,  Ramesh Shankar

IPC: G06F16/27 ,  G06F16/23

Abstract: Adaptive replication of changes may be performed for copies of a database. Log records may be generated and stored that correspond to changes to a database while a database is being copied. If the changes to be applied to a copy of the database is less than or equal to a threshold number of changes, then the copy of the database may be updated using the stored log records. If the changes to be applied to the copy of the database are greater than the threshold number of changes, then the copy of the database may be updated using data stored in the database.