Virtual full backups

• US 9,910,736 B2
• Filed: 12/31/2014
• Issued: 03/06/2018
• Est. Priority Date: 10/31/2011
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Wertheimer, Steven, Olagappan, Muthu, Guzman, Raymond, Fisher, William, Anand, Beldalker, Rao, Sriram Nagaraja, Plakyda, Chris, Roy, Debjyoti, Dizdar, Senad
• Primary Examiner(s): Rostami, Mohammad S
• Application Number:
  US14/588,149
• Publication Number:
  US 20150178169A1
• Time in Patent Office: 1,161 Days
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1464 for networked environments
• 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
• CPC Class Codes: G06F 2201/815 Virtual middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

According to embodiments described herein, a backup server maintains backup data for a set of data, which includes data for a first block and a second block. Backup data for the first and second block include backup data for a plurality of versions of the first and second block. A distinct watermark is stored for each version of the first block and each version of the second block. In response to a request to perform a restoration operation on the set of data, a particular version of the first block and a particular version of the second block are selected to use in the restoration operation by comparing a restoration target with the watermarks of the version of the first block and second block. The selected version of the first block has a different watermark than the selected version of the second block.

Claims

1. A method comprising:

maintaining, by a client system, a set of data;

wherein the set of data includes a plurality of data blocks;

associating each respective data block in the plurality of data blocks with a respective watermark;

in response to every change that is committed to a given data block, creating a new version of the given data block and associating a new watermark with the new version of the given data block, wherein the new watermark is different than the watermark associated with all other versions of the given data block;

wherein, for each data block of the plurality of data blocks, the watermark associated with the data block indicates a version of the respective data block and is different than the watermark associated with any other version of the data block;

for each respective data block in the plurality of data blocks, determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to a backup server; and

sending, by the client system to the backup server, the set of backup data.

2. The method of claim 1, wherein determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to the backup server comprises determining, based on the respective watermark, whether data within the respective data block has changed since a previous backup of the set of data;

wherein the respective data block is included in the set of backup data if data within the respective data block has changed since the previous backup of the set of data; and

wherein the respective data block is not included in the set of backup data if data within the respective data block has not changed since the previous backup of the set of data.

3. The method of claim 1, wherein the respective watermark is a system change number (SCN);

wherein determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to the backup server comprises comparing the SCN to a checkpoint SCN associated with a previous backup of the set of data;

wherein the respective data block is included in the set of backup data if the SCN is higher than the checkpoint SCN; and

wherein the respective data block is not included in the set of backup data if the SCN is less than or equal to the checkpoint SCN.

4. The method of claim 1, wherein determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to the backup server comprises reading a target watermark associated with a previously backed up version of the respective data block;

comparing the respective watermark to the target watermark;

wherein the respective data block is included in the set of backup data if the respective watermark and the target watermark are different; and

wherein the respective data block is not included in the set of backup data if the respective watermark and the target watermark are identical.

5. The method of claim 1, wherein the set of backup data includes a subset of a data blocks from the plurality of data blocks.

6. The method of claim 1, wherein the set of backup data includes the respective watermark for each data block included in the set of backup data.

7. The method of claim 1, wherein the backup server defragments a pool of data blocks used to backup the set of data after receiving the set of backup data from the client system.

8. The method of claim 1, further comprising:

sending, from the client system to the backup server, a request to perform a restoration operation on the set of data, wherein the request specifies a restoration target; and

receiving, from the backup server, a backup set of data blocks that have watermarks that satisfy the restoration target.

9. The method of claim 8,

wherein the restoration target specifies a target time for recovery;

and

wherein the backup set of data blocks are versions of the plurality of data blocks that existed on the client system at the target time for recovery.

10. The method of claim 1, wherein the backup server purges one or more versions of a data block used to backup the set of data based on a set of watermark data maintained for the data block.

11. A non-transitory computer-readable medium storing instructions, which, when executed by one or more processors, cause one or more computing devices to perform operations comprising:

maintaining, by a client system, a set of data;

wherein the set of data includes a plurality of data blocks;

associating each respective data block in the plurality of data blocks with a respective watermark;

in response to every change that is committed to a given block, creating a new version of the given data block and associating a new watermark with the new version of the given data block, wherein the new watermark is different than the watermark associated with all other versions of the given data block;

wherein, for each data block of the plurality of data blocks, the watermark associated with the data block indicates a version of the respective data block and is different than the watermark associated with any other version of the data block;

for each respective data block in the plurality of data blocks, determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to a backup server; and

sending, by the client system to the backup server, the set of backup data.

12. The non-transitory computer-readable medium of claim 11, wherein determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to the backup server comprises determining, based on the respective watermark, whether data within the respective data block has changed since a previous backup of the set of data;

wherein the respective data block is included in the set of backup data if data within the respective data block has changed since the previous backup of the set of data; and

wherein the respective data block is not included in the set of backup data if data within the respective data block has not changed since the previous backup of the set of data.

13. The non-transitory computer-readable medium of claim 11, wherein the respective watermark is a system change number (SCN);

wherein determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to the backup server comprises comparing the SCN to a checkpoint SCN associated with a previous backup of the set of data;

wherein the respective data block is included in the set of backup data if the SCN is higher than the checkpoint SCN; and

wherein the respective data block is not included in the set of backup data if the SCN is less than or equal to the checkpoint SCN.

14. The non-transitory computer-readable medium of claim 11, wherein determining, based on the respective watermark associated with the respective data block, whether to include the respective data block in a set of backup data to send to the backup server comprises reading a target watermark associated with a previously backed up version of the respective data block;

comparing the respective watermark to the target watermark;

wherein the respective data block is included in the set of backup data if the respective watermark and the target watermark are different; and

wherein the respective data block is not included in the set of backup data if the respective watermark and the target watermark are identical.

15. The non-transitory computer-readable medium of claim 11, wherein the set of backup data includes a subset of a data blocks from the plurality of data blocks.

16. The non-transitory computer-readable medium of claim 11, wherein the set of backup data includes the respective watermark for each data block included in the set of backup data.

17. The non-transitory computer-readable medium of claim 11, wherein the backup server defragments a pool of data blocks used to backup the set of data after receiving the set of backup data from the client system.

18. The non-transitory computer-readable medium of claim 11, wherein the instructions cause the one or more computing devices to perform operations further comprising:

sending, from the client system to the backup server, a request to perform a restoration operation on the set of data, wherein the request specifies a restoration target; and

receiving, from the backup server, a backup set of data blocks that have watermarks that satisfy the restoration target.

19. The non-transitory computer-readable medium of claim 18,

wherein the restoration target specifies a time;

and

wherein the backup set of data blocks are versions of the plurality of data blocks that existed on the client system at the specified time.

20. The non-transitory computer-readable medium of claim 11, wherein the backup server purges one or more versions of a data block used to backup the set of data based on a set of watermark data maintained for the data block.