Non-blocking backup in a log replay node for tertiary initialization

Patent metadata

Field	Value
Publication number	US-11226876-B2
Application number	US-201816014206-A
Country	US
Kind code	B2
Filing date	Jun 21, 2018
Priority date	Jun 21, 2018
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

Disclosed herein are system, method, and computer program product embodiments for non-blocking backup for tertiary initialization in a log replay only node. An embodiment operates by performing a standard log replay on a secondary server and briefly suspending the standard log replay in response to tertiary initialization. Further, the secondary server may determine backup block information and perform a page-aligned backup process from the secondary server to a tertiary server. Additionally, the secondary server may determine log replay block information, and perform a modified log replay concurrently with the backup process based on the backup block information.

First claim

What is claimed is:

1. A method for initializing a tertiary server within a three-tiered replication system, comprising:
receiving log information associated with a primary server, the log information corresponding to first database operations performed at the primary server;
performing, by the secondary server, a standard log replay over the log information;
temporarily suspending the standard log replay at a position of the log information;
determining backup block information, the backup block information including backup block identifiers identifying one or more backup blocks of the secondary server to be backed up during a page-aligned backup process and a status of the backup process;
performing the page-aligned backup process from the secondary server to the tertiary server, the page-aligned backup process associated with second database operations performed prior to the position; and
performing, by the secondary server, a modified log replay based on the backup block information and the log information.

2. The method of claim 1 , wherein suspending the standard log replay at the position of the log information, comprises suspending the standard log replay at a recovery checkpoint of the log information.

3. The method of claim 1 , wherein performing the modified log replay based on the backup block information and the log information, comprises:
determining replay block identifiers identifying one or more replay blocks to be modified by third database operations performed after the position; and
determining, based on the backup information, that none of the backup block identifiers are the same as the replay block identifiers; and
replaying the log information.

4. The method of claim 1 , wherein performing the modified log replay based on the backup block information and the log information, comprises:
determining that the backup process is complete based on the backup block information; and
replaying the log information.

5. The method of claim 1 , wherein the backup block identifiers are initial backup block identifiers, and performing the modified log replay based on the backup block information and the log information, comprises:
determining initial replay block identifiers identifying one or more replay blocks to be modified by third database operations performed after the position; and
determining modified replay block identifiers corresponding to the initial replay block identifiers having a matching backup block identifier of the backup block identifiers;
determining a first page including a first block of the modified replay block identifiers;
determining a second page including a last block of the modified replay block identifiers;
determining a range of the one or more replay blocks spanning from the first page to the second page;
determining log replay backup blocks of the one or more backup blocks, the log replay backup blocks corresponding to the range; and
determining modified backup block identifiers by removing the initial backup block identifiers corresponding to the log replay backup blocks.

6. The method of claim 5 , wherein performing the page-aligned backup process from the secondary server to the tertiary server, comprises:
performing the page-aligned backup process based on the modified backup block identifiers.

7. The method of claim 1 , wherein the one or more backup blocks are encrypted backup blocks, and performing the page-aligned backup process from the secondary server to the tertiary server, comprises:
determining clear text backup blocks based on decrypting the encrypted backup blocks; and
backing up the clear text backup blocks to the tertiary server.

8. The method of claim 1 , wherein the primary server includes at least one of an in-memory row store or an in-memory column store database.

9. The method of claim 1 , wherein the secondary server includes a log replay only server that does not include at least one of a transaction manager, checkpoint capabilities, or a backup manager.

10. A non-transitory computer-readable device having instructions stored thereon that, when executed by at least one computing device, causes the at least one computing device to perform operations comprising:
receiving log information associated with a primary server, the log information corresponding to first database operations performed at the primary server;
performing, by the secondary server, a standard log replay over the log information;
temporarily suspending the standard log replay at a position of the log information;
determining backup block information, the backup block information including backup block identifiers identifying one or more backup blocks of the secondary server to be backed up during a page-aligned backup process and a status of the backup process;
performing the page-aligned backup process from the secondary server to a tertiary server, the page-aligned backup process associated with second database operations performed prior to the position; and
performing a modified log replay based on the backup block information and the log information.

11. The non-transitory computer-readable device of claim 10 , wherein the one or more backup blocks are encrypted backup blocks, and performing the page-aligned backup process from the secondary server to the tertiary server, comprises:
determining clear text backup blocks based on decrypting the encrypted backup blocks; and
backing up the clear text backup blocks to the tertiary server.

12. The non-transitory computer-readable device of claim 10 , wherein suspending the standard log replay at the position of the log information, comprises suspending the standard log replay at a recovery checkpoint of the log information.

13. The non-transitory computer-readable device of claim 10 , wherein the backup block identifiers are initial backup block identifiers, and performing the modified log replay based on the backup block information and the log information, comprises:
determining initial replay block identifiers identifying one or more replay blocks to be modified by third database operations performed after the position; and
determining modified replay block identifiers corresponding to the initial replay block identifiers having a matching backup block identifier of the backup block identifiers;
determining a first page including a first block of the modified replay block identifiers;
determining a second page including a last block of the modified replay block identifiers;
determining a range of the one or more replay blocks spanning from the first page to the second page;
determining log replay backup blocks of the one or more backup blocks, the log replay backup blocks corresponding to the range; and
determining modified backup block identifiers by removing the initial backup block identifiers corresponding to the log replay backup blocks.

14. The non-transitory computer-readable device of claim 13 , wherein performing the page-aligned backup process from the secondary server to the tertiary server, comprises:
performing the page-aligned backup process based on the modified backup block identifiers.

15. The non-transitory computer-readable device of claim 10 , wherein the secondary server includes a log replay only server that does not include at least one of a transaction manager, checkpoint capabilities, or a backup manager.

16. A secondary server system, comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive log information associated with a primary server, the log information corresponding to first databas

Assignees

• Sap Se

Inventors

• Gottapu Simhachala Sasikanth
• Wang Yahong
• Marathe Nandan
• Agarwal Anant

Classifications

• G06F11/1469

  Backup restoration techniques · CPC title

• G06F11/1464

  for networked environments · CPC title

• G06F2201/80

  Database-specific techniques · CPC title

• G06F2201/87

  Monitoring of transactions · CPC title

• G06F11/2028 Primary

  eliminating a faulty processor or activating a spare · CPC title