Data restoration method and system

• US 9,778,998 B2
• Filed: 03/17/2015
• Issued: 10/03/2017
• Est. Priority Date: 03/17/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Wen, Jijun, Nie, Yuanyuan, Xu, Wentao
• Primary Examiner(s): Patel, Kamini
• Application Number:
  US14/660,460
• Publication Number:
  US 20150261626A1
• Time in Patent Office: 931 Days
• Field of Search: 714 16
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor

Abstract

Embodiments of the present invention disclose a data restoration method, including: after a transaction is submitted, saving a generated transaction log to a buffer of a current node, and backing up the transaction log to a buffer of at least one backup node except the current node; writing the transaction log saved in the buffer of the current node or the transaction log backed up in the buffer of the backup node into a transaction log file in a disk, where the transaction log file in the disk is used for restoring data of the current node; and restoring, based on the transaction log file in the disk, lost data of the current node when a data loss event occurs in the current node. By means of the present invention, a risk of system data can be reduced, and durability, safety, and reliability of the system data can be improved.

Claims

1. A data restoration method, the method comprising:

after a transaction is submitted, saving a generated transaction log to a buffer of a current node;

registering, at the current node, an address of a buffer of one or more backup nodes, the one or more backup nodes being different than the current node;

backing up the transaction log to the buffer of the registered address of the one or more backup nodes;

writing the transaction log backed up in the buffer of the one or more backup nodes into a transaction log file in a disk, wherein the transaction log file in the disk is used for restoring data of the current node; and

restoring, based on the transaction log file in the disk, lost data of the current node when a data loss event occurs in the current node.

2. The method according to claim 1, wherein before saving the generated transaction log to a buffer of the current node the method further comprises:

setting a safety level of the current node and a backup node quantity corresponding to the safety level;

selecting, for the current node from one or more nodes different than the current node, one or more nodes as one or more backup nodes, wherein a quantity of the one or more selected nodes is the backup node quantity corresponding to the safety level; and

using a buffer of the selected backup node as a buffer for backing up the transaction log.

3. The method according to claim 2, wherein selecting, for the current node from one or more nodes different than the current node, one or more backup nodes comprises:

selecting the one or more backup nodes from one or more nodes different than the current node and adjacent to the current node, wherein a quantity of the selected one or more backup nodes is equal to the backup node quantity corresponding to the safety level;

or selecting the one or more backup nodes from one or more nodes different than the current node and comprising a vacant buffer, wherein a quantity of the selected one or more backup nodes is equal to the backup node quantity corresponding to the safety level.

4. The method according to claim 1, further comprising:

determining, by the current node, whether the transaction log file in the disk includes the transaction log saved in the buffer of the current node;

when it is determined that the transaction log file in the disk does not include the transaction log saved in the buffer of the current node, writing, by the current node, the transaction log saved in the buffer of the current node into the transaction log file in the disk.

5. The method according to claim 1, wherein writing the transaction log backed up in the buffer of the one or more backup nodes into a transaction log file in a disk comprises:

determining, by the one or more backup nodes, whether the transaction log file in the disk comprises the transaction log backed up in the buffer of the one or more backup nodes;

when it is determined that the transaction log file in the disk does not include the transaction log backed up in the buffer of the at least one backup node, writing, by the one or more backup nodes, the transaction log backed up in the buffer of the one or more backup nodes into the transaction log file in the disk.

6. The method according to claim 1, wherein the disk comprises a current node disk only supporting access by the current node, and a backup node disk only supporting access by the one or more backup nodes;

writing, by the current node, the transaction log saved in the buffer of the current node into a transaction log file in the current node disk, wherein the transaction log file in the current node disk is used for restoring the data of the current node; and

wherein writing the transaction log backed up in the buffer of the one or more backup nodes into a transaction log file in a disk comprises;

writing, by the backup node, the transaction log backed up in the buffer of the one or more backup nodes into a transaction log file in the backup node disk, wherein the transaction log file in the backup node disk is used for restoring the data of the current node.

7. The method according to claim 6, wherein restoring, based on the transaction log file in the disk, lost data of the current node when a data loss event occurs in the current node comprises:

reading the transaction log file in the current node disk;

reading the transaction log file in the backup node disk;

selecting, from the read transaction log files, a transaction log file having most complete information; and

restoring the lost data of the current node by using the transaction log file having the most complete information.

8. A data restoration system, comprising:

a computing hardware; and

a non-transitory computer-readable storage medium including computer-executable instructions executed by the computing hardware to perform, on the data restoration system, the method comprising;

after a transaction is submitted, saving a generated transaction log to a buffer of a current node;

registering, at the current node, an address of a buffer of one or more backup nodes, the one or more backup nodes being different than the current node;

backing up the transaction log to the buffer of the registered address of the one or more backup nodes;

writing the transaction log backed up in the buffer for backing up the transaction log into a transaction log file in a disk, wherein the transaction log file in the disk is used for restoring data of the current node; and

restoring, when a data loss event occurs in the current node, lost data of the current node based on the transaction log file in the disk.

9. The system according to claim 8, further comprising instructions for:

setting a safety level of the current node and a backup node quantity corresponding to the safety level; and

selecting, for the current node from one or more nodes different than the current node, one or more nodes as the one or more backup nodes, wherein a quantity of the one or more selected nodes is equal to the backup node quantity corresponding to the safety level, and

using a buffer of the one or more backup nodes as the buffer for backing up the transaction log.

10. The system according to claim 9, further comprising instructions for selecting the one or more backup nodes from one or more nodes different than the current node and adjacent to the current node, wherein a quantity of the selected one or more backup nodes is equal to the backup node quantity corresponding to the safety level;

or

selecting the one or more backup nodes from one or more nodes different than the current node and including a vacant buffer, wherein a quantity of the selected one or more backup nodes is equal to the backup node quantity corresponding to the safety level.

11. The system according to claim 8, further comprising instructions for:

determining whether the transaction log file in the disk includes the transaction log saved in the buffer of the current node;

when it is determined that the transaction log file in the disk does not include the transaction log saved in the buffer of the current node, generating a first writing message and sending the first writing message to a first writing unit, wherein the first writing unit, after receiving the first writing message, is configured to write the transaction log saved in the buffer of the current node into the transaction log file in the disk.

12. The system according to claim 8, further comprising instructions for:

determining whether the transaction log file in the disk includes the transaction log backed up in the buffer of the one or more backup nodes;

when it is determined that the transaction log file in the disk does not include the transaction log backed up in the buffer of the one or more backup nodes, generating a second writing message and sending the second writing message to a second writing unit, wherein the second writing unit, after receiving the second writing message, write the transaction log backed up in the buffer of the one or more backup nodes into the transaction log file in the disk.

13. The system according to claim 8, wherein the disk comprises a current node disk only supporting access by the current node, and a backup node disk only supporting access by the one or more backup nodes, further comprising instructions for:

writing the transaction log saved in the buffer of the current node into a transaction log file in the current node disk, wherein the transaction log file in the current node disk is used for restoring the data of the current node; and

writing the transaction log backed up in the buffer of the one or more backup nodes into a transaction log file in the backup node disk, wherein the transaction log file in the backup node disk is used for restoring the data of the current node.

14. The system according to claim 13, further comprising instructions for:

reading the transaction log file in the current node disk and reading the transaction log file in the backup node disk;

selecting from the transaction log files read by the reading module, a transaction log file having most complete information; and

restoring the lost data of the current node by using the transaction log file having the most complete information.