公开(公告)号：US11080262B1

公开(公告)日：2021-08-03

申请号：US16586497

申请日：2019-09-27

Applicant: Amazon Technologies, Inc.

Inventor： Justin Levandoski ,  Niket Goel ,  Tengiz Kharatishvili ,  Alexandre Olegovich Verbitski ,  Kamal Kant Gupta ,  Xiaofeng Bao

IPC: G06F16/23 ,  G06F16/22 ,  G06F16/2455

Abstract: Systems and methods are disclosed to implement, in a database system, database engine nodes that implement multi-page writes as an atomic operation. In embodiments, the database system may include multiple database engine nodes that optimistically perform page writes locally without checking for potential conflicts at a shared storage system. The storage system will detect and report conflicting writes on a single page. To ensure that a group of writes to multiple pages occur atomically, the database engine node maintains a transaction context for the group, so that if a page conflict is later detected for any write in the group, the entire group will be rolled back at the database engine node and the storage system. In embodiments, the transaction context will track subsequent writes generated by the node to any page written by the group, so that these subsequent writes are also rolled back with the group.

公开(公告)号：US11874796B1

公开(公告)日：2024-01-16

申请号：US16586235

申请日：2019-09-27

Applicant: Amazon Technologies, Inc.

Inventor： Tengiz Kharatishvili ,  Alexandre Olegovich Verbitski ,  Justin Levandoski ,  Niket Goel ,  Kamal Kunt Gupta ,  Xiaofeng Bao

IPC: G06F15/16 ,  G06F16/16 ,  G06F16/18 ,  G06F16/17 ,  G06F16/176

CPC classification number: G06F16/162 ,  G06F16/1734 ,  G06F16/1767 ,  G06F16/1873

Abstract: Systems and methods are disclosed to implement, in a multi-writer database system, a database engine node that optimistically sends queued purge operations to a backend storage system without waiting for acknowledgement of previous operations from the storage system. If a conflict is later detected for a particular operation, the database engine node may retry some portion of the purge operations in the queue. In embodiments, the purge operations are performed as part of a garbage collection phase of a multi-version concurrency control (MVCC) protocol, where unneeded versions of objects previously generated for isolated snapshots are deleted. In embodiments, the operations in the queue may be grouped so that a rejection of one operation in the group will cause the entire group to be retried. Because these purge operations are idempotent and directed to objects that are invisible, they may be freely retried in arbitrary order, without maintaining any rollback state.

公开(公告)号：US11860869B1

公开(公告)日：2024-01-02

申请号：US16457154

申请日：2019-06-28

Applicant: Amazon Technologies, Inc.

Inventor： Sangyong Hwang ,  Justin Levandoski ,  Yongsik Yoon ,  Kamal Kant Gupta ,  Saileshwar Krishnamurthy ,  Ippokratis Pandis ,  Michail Petropoulos

IPC: G06F16/2453 ,  G06F16/23 ,  G06F16/25

CPC classification number: G06F16/24542 ,  G06F16/2379 ,  G06F16/254

Abstract: Queries to a consistent view of a data set across different types of query engines are performed. Portions of a query received at a first type of query engine that can be performed at a different type of a query engine can be identified. A consistent view of a data set stored in a common data store can be provided by the first type of query engine to the second query engine. When the different type of query engine performs the portion of the query, the different type of query engine applies the consistent view of the data set. A result for the query can be returned by the first type of query engine based on results from the different type of query engine.

公开(公告)号：US11366802B1

公开(公告)日：2022-06-21

申请号：US16586355

申请日：2019-09-27

Applicant: Amazon Technologies, Inc.

Inventor： Tengiz Kharatishvili ,  Alexandre Olegovich Vebitski ,  Justin Levandoski ,  Niket Goel ,  Xiang Peng ,  Kamal Kant Gupta ,  Xiaofeng Bao

IPC: G06F16/23 ,  G06F16/18

Abstract: Batch processing of undo log records may be performed for rolling back a database transaction. When a rollback operation for a database transaction is performed, undo log records from an undo log to rollback the database transaction are divided into different groups of undo log records. Different requests for the different undo log records are sent to a storage system to be performed. If a conflict is detected for an undo log record in a group, an indication of the conflicting undo log record may be provided to indicate the conflict. The group of undo log records may be resent with a request to reapply the undo log records in the group. When all groups have been identified as successfully completed, then the rollback operation may be considered completed.

公开(公告)号：US11379463B1

公开(公告)日：2022-07-05

申请号：US16586563

申请日：2019-09-27

Applicant: Amazon Technologies, Inc.

Inventor： Tengiz Kharatishvili ,  Alexandre Olegovich Verbitski ,  Justin Levandoski ,  Niket Goel ,  Kamal Kant Gupta ,  Xiaofeng Bao ,  Punit Rajgaria

IPC: G06F16/00 ,  G06F16/23 ,  G06F9/46

Abstract: Systems and methods are disclosed to implement, in a database system, a database engine node that generates write tracking transactions to atomically enforce cross-page constraints for write operations. In embodiments, the database system may include multiple database engine nodes that optimistically perform page writes without checking for potential conflicts at a shared storage system. The storage system is configured to detect and report conflicting writes on the same page. To cause the storage system to report cross-page conflicts for a write, the database engine node creates a transaction that includes the write and a write tracker (WT) operation for a tracked page. The WT operation will cause the storage system to report any conflicting writes to the tracked page before the actual write is accepted by the storage system. If a reported conflict is not favorably resolved, the database engine node will abort the entire transaction, including the actual write.