公开(公告)号：US20180074915A1

公开(公告)日：2018-03-15

申请号：US15266375

申请日：2016-09-15

Applicant: Oracle International Corporation

Inventor： Hongjie Yang ,  Yunrui Li ,  Mahesh Baburao Girkar

IPC: G06F11/14 ,  G06F17/30

Abstract: Herein are techniques of zero data loss with asynchronously replicated redo logs. In an embodiment, a first server instance (FSI) of a plurality of server instances (PSI) of a primary database (PDB) sends, to a standby database (SDB) during an shutdown of FSI, a first recovery count (RC) and a remainder of an instance redo log (IRL). In response to recovering FSI, a second server instance of PSI increments a recovery counter to a second RC (SRC), publishes SRC to PSI, and sends SRC to SDB. After restarting FSI, FSI makes a change to contents of PDB, and stores, into IRL, a redo entry that defines the change. During failover, a database management system (DBMS) detects whether RCs associated with FSRL and SSRL are unanimous. If unanimous, DBMS fully rolls forward SDB by replaying FSRL and SSRL. Otherwise, DBMS limits replay and indicates that FSRL and SSRL might be inconsistent.

公开(公告)号：US11586614B2

公开(公告)日：2023-02-21

申请号：US16932633

申请日：2020-07-17

Applicant: Oracle International Corporation

Inventor： James W. Stamos ,  Mahesh Baburao Girkar ,  Wei Ming Hu ,  Juan R. Loaiza ,  Sachin Vijaykumar Sonawane ,  Hongjie Yang

IPC: G06F16/23 ,  G06F16/21 ,  H04L9/06 ,  H04L9/00

Abstract: Distributed ledgered data is stored within a distributed persistent storage system comprising multiple persistent storage systems as distributed ledgered participants. In various embodiments, the distributed ledgered data is maintained using the native capabilities of a persistent storage system. The distributed ledgered data is replicated as persistent data objects in a “ledgered repository of objects” that are replicated at each of the persistent storage systems. Changes at one persistent storage system are recorded within a block in a distributed blockchain that is distributed across each of the other distributed ledgered participants. The other distributed ledgered participants read the changes from the blockchain and apply the changes to the respective replicas at each of the other distributed ledgered participants. Hence, this approach is referred to as blockchain apply. Blockchain apply may be used to replicate the repository objects of various forms of PSSs. In a DBMS, a repository of objects is a table, where each record or row is an object in the repository. In a file system, a repository of objects is a directory, where each directory and file therein is an object in the repository. In a document storage system (DOCS), a repository of objects is a collection of documents, where each document is an object in the repository.

公开(公告)号：US10698771B2

公开(公告)日：2020-06-30

申请号：US15266375

申请日：2016-09-15

Applicant: Oracle International Corporation

Inventor： Hongjie Yang ,  Yunrui Li ,  Mahesh Baburao Girkar

IPC: G06F7/00 ,  G06F17/00 ,  G06F11/14 ,  G06F16/27 ,  G06F11/20

Abstract: Herein are techniques of zero data loss with asynchronously replicated redo logs. In an embodiment, a first server instance (FSI) of a plurality of server instances (PSI) of a primary database (PDB) sends, to a standby database (SDB) during an shutdown of FSI, a first recovery count (RC) and a remainder of an instance redo log (IRL). In response to recovering FSI, a second server instance of PSI increments a recovery counter to a second RC (SRC), publishes SRC to PSI, and sends SRC to SDB. After restarting FSI, FSI makes a change to contents of PDB, and stores, into IRL, a redo entry that defines the change. During failover, a database management system (DBMS) detects whether RCs associated with FSRL and SSRL are unanimous. If unanimous, DBMS fully rolls forward SDB by replaying FSRL and SSRL. Otherwise, DBMS limits replay and indicates that FSRL and SSRL might be inconsistent.

公开(公告)号：US11086902B2

公开(公告)日：2021-08-10

申请号：US16144126

申请日：2018-09-27

Applicant: Oracle International Corporation

Inventor： Steven McGee ,  Jiangbin Luo ,  Benedicto Garin ,  Mahesh Girkar ,  Michael Harvey ,  Nitin Karkhanis ,  Steve Lee ,  Juan Loaiza ,  Robert McGuirk ,  Hongjie Yang

IPC: G06F16/27

Abstract: Disclosed are methods and apparatuses to provide a redo repeater that allows for no data loss protection without the performance impact to the primary database even when a significant geographical distance separates the primary and standby databases. The Repeater is a lightweight entity that receives redo from the primary database with the purpose of redistributing that redo throughout the primary/standby system configuration. The Repeater able to extend no data loss protection and switchover functionality to terminal standby databases even though the primary database does not need to have a direct connection with those destinations.

公开(公告)号：US20210034606A1

公开(公告)日：2021-02-04

申请号：US16932633

申请日：2020-07-17

Applicant: Oracle International Corporation

Inventor： James W. Stamos ,  Mahesh Baburao Girkar ,  Wei Ming Hu ,  Juan R. Loaiza ,  Sachin Vijaykumar Sonawane ,  Hongjie Yang

IPC: G06F16/23 ,  G06F16/21 ,  H04L9/06

Abstract: Distributed ledgered data is stored within a distributed persistent storage system comprising multiple persistent storage systems as distributed ledgered participants. In various embodiments, the distributed ledgered data is maintained using the native capabilities of a persistent storage system. The distributed ledgered data is replicated as persistent data objects in a “ledgered repository of objects” that are replicated at each of the persistent storage systems. Changes at one persistent storage system are recorded within a block in a distributed blockchain that is distributed across each of the other distributed ledgered participants. The other distributed ledgered participants read the changes from the blockchain and apply the changes to the respective replicas at each of the other distributed ledgered participants. Hence, this approach is referred to as blockchain apply. Blockchain apply may be used to replicate the repository objects of various forms of PSSs. In a DBMS, a repository of objects is a table, where each record or row is an object in the repository. In a file system, a repository of objects is a directory, where each directory and file therein is an object in the repository. In a document storage system (DOCS), a repository of objects is a collection of documents, where each document is an object in the repository.

公开(公告)号：US20190026353A1

公开(公告)日：2019-01-24

申请号：US16144126

申请日：2018-09-27

Applicant: Oracle International Corporation

Inventor： Steven McGee ,  Jiangbin Luo ,  Benedicto GARIN ,  Mahesh Girkar ,  Michael Harvey ,  Nitin Karkhanis ,  Steve Lee ,  Juan Loaiza ,  Robert McGuirk ,  Hongjie Yang

IPC: G06F17/30

Abstract: Disclosed are methods and apparatuses to provide a redo repeater that allows for no data loss protection without the performance impact to the primary database even when a significant geographical distance separates the primary and standby databases. The Repeater is a lightweight entity that receives redo from the primary database with the purpose of redistributing that redo throughout the primary/standby system configuration. The Repeater able to extend no data loss protection and switchover functionality to terminal standby databases even though the primary database does not need to have a direct connection with those destinations.