Restore of secondary data using thread pooling

• US 10,558,374 B2
• Filed: 05/11/2018
• Issued: 02/11/2020
• Est. Priority Date: 05/14/2015
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Vijayan, Manoj Kumar, Agrawal, Saurabh, Attarde, Deepak Raghunath
• Primary Examiner(s): Gu, Shawn X
• Application Number:
  US15/978,019
• Publication Number:
  US 20180329635A1
• Time in Patent Office: 641 Days
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 9/466 Transaction processing

Abstract

A system according to certain aspects may include a secondary storage controller computer configured to: in response to a first instruction to obtain a first secondary copy of a first data set from a secondary storage device(s), the first instruction associated with a first restore operation: instantiate a first restore thread on a processor of the secondary storage controller computer; using the first restore thread, retrieve the first secondary copy from the secondary storage device(s); and forward the retrieved first secondary copy to a primary storage subsystem for storage; and in response to a second instruction to obtain a second secondary copy of a second data set from the secondary storage device(s), the second instruction associated with a second restore operation: using the first restore thread, retrieve the second secondary copy from the secondary storage device(s); and forward the retrieved second secondary copy to the primary storage subsystem for storage.

Claims

1. A system for replicating data in secondary storage, the system comprising:

a source system comprising a source client computing device comprising;

computer hardware, one or more source primary storage devices associated with the source client computing device, a plurality of source secondary storage controller computers comprising computer hardware, and one or more source secondary storage devices; and

a destination system comprising one or more destination secondary storage devices,

wherein at least one source secondary storage controller computer of the plurality of source secondary storage controller computers is configured to;

maintain a look-ahead thread pool of look-ahead restore threads executing on one or more hardware processors of the computer hardware of the at least one source secondary storage controller computer;

receive a restore request to restore a secondary copy of primary data previously stored on the one or more source primary storage devices from the one or more source secondary storage devices to the one or more destination secondary storage devices, wherein the restore request restores data in a first order;

select at least one of the look-ahead restore threads in the look-ahead thread pool to be used to process the restore request; and

retrieve, using the at least one selected look-ahead restore threads, the secondary copy from the one or more source secondary storage devices and forward the retrieved secondary copy to the destination system for storage on the one or more destination secondary storage devices, wherein the at least one selected look-ahead restore thread restores data in a second order that is different than the first order based on metadata associated with the restore request.

2. The system of claim 1, wherein the restore request is associated with a replication operation in which deduplicated data is restored from the one or more source secondary storage devices to the one or more destination secondary storage devices.

3. The system of claim 1, wherein the restore request is associated with one of a plurality of restore operations to be performed as part of a continuous replication process to replicate data stored in the one or more source secondary storage devices onto the one or more destination secondary storage devices, wherein the plurality of restore operations are to be performed according to a predetermined schedule at a regular interval.

4. The system of claim 1, wherein the restore request corresponds to a scheduled backup of the primary data from the one or more source primary storage devices to the one or more source secondary storage devices.

5. The system of claim 1, wherein the destination system further comprises a plurality of destination secondary storage controller computers comprising computer hardware, wherein at least one destination secondary storage controller computer of the plurality of destination secondary storage controller computers is configured to restore the forwarded secondary copy stored in the one or more destination secondary storage devices onto one or more destination primary storage devices.

6. The system of claim 1, wherein the at least one selected look-ahead thread is configured to:

(i) process a data structure that includes a number of data blocks arranged in the first order within the secondary copy, and (ii) generate the second order for reading the number of data blocks that is different from the first order; and

read the number of data blocks from the one or more source secondary storage devices according to the second order.

7. The system of claim 6, wherein reading the number of data blocks according to the second order comprises reading a first data block stored in a first file on the one or more source secondary storage devices immediately after a second data block in the first file, whereas reading the number of data blocks according to the first order would comprise reading at least one other data block in a second file on the one or more source secondary storage devices that is different from the first file between reading the first data block and reading the second data block.

8. The system of claim 7, wherein the at least one source secondary storage controller computer is further configured to open the first file, and while the file is open and without closing the first file, read both the first data block and the second data block.

9. The system of claim 1, wherein the at least one source secondary storage controller computer is further configured to:

receive another restore request to restore another secondary copy from the one or more source secondary storage devices to the one or more destination secondary storage devices;

select another one of the look-ahead restore threads in the thread pool to use to process said another restore request; and

retrieve, using said another look-ahead restore thread, said another secondary copy from the one or more source secondary storage devices and forward said another secondary copy to the destination system for storage on the one or more destination secondary storage devices.

10. The system of claim 9, wherein the secondary controller computer is further configured to determine, based on a metric associated with said another look-ahead restore thread, that said another look-ahead restore thread is not to be used to process said another restore request to restore said another secondary copy.

11. A method for replicating data in secondary storage, the method comprising:

with a first computer comprising computer hardware and residing in a source system comprising a source client computing device comprising computer hardware, one or more source primary storage devices associated with the source client computing device, and one or more source secondary storage devices,

maintaining a look-ahead thread pool having look-ahead restore threads executing on one or more hardware processors of the computer hardware of the first computer;

receiving a restore request to restore a secondary copy of primary data previously stored on the one or more source primary storage devices from the one or more source secondary storage devices to one or more destination secondary storage devices in a destination system, wherein the restore request restores data in a first order;

selecting at least one of the look-ahead restore threads in the look-ahead thread pool to be used to process the restore request; and

retrieving, using the at least one selected look-ahead restore threads, the secondary copy from the one or more source secondary storage devices and forward the retrieved secondary copy to the destination system for storage on the one or more destination secondary storage devices, wherein the at least one selected look-ahead restore thread restores data in a second order that is different than the first order.

12. The method of claim 11, wherein the restore request is associated with a replication operation in which deduplicated data is restored from the one or more source secondary storage devices to the one or more destination secondary storage devices.

13. The method of claim 11, wherein the restore request is associated with one of a plurality of restore operations to be performed as part of a continuous replication process to replicate data stored in the one or more source secondary storage devices onto the one or more destination secondary storage devices, wherein the plurality of restore operations are to be performed according to a predetermined schedule at a regular interval.

14. The method of claim 11, wherein the restore request corresponds to a scheduled backup of the primary data from the one or more source primary storage devices to the one or more source secondary storage devices.

15. The method of claim 11, further comprising restoring the forwarded secondary copy stored in the one or more destination secondary storage devices onto one or more destination primary storage devices in the destination system.

16. The method of claim 11, further comprising, with the at least one selected look-ahead threads:

reading a number of data blocks from the one or more source secondary storage devices according to the second order.

17. The method of claim 16, wherein reading the number of data blocks according to the second order comprises reading a first data block stored in a first file on the one or more source secondary storage devices immediately after a second data block in the first file, whereas reading the number of data blocks according to the first order would comprise reading at least one other data block in a second file on the one or more source secondary storage devices that is different from the first file between reading the first data block and reading the second data block.

18. The method of claim 17, further comprising opening the first file, and while the file is open and without closing the first file, reading both the first data block and the second data block.

19. The method of claim 11, further comprising:

receiving another restore request to restore another secondary copy from the one or more source secondary storage devices to the one or more destination secondary storage devices;

selecting another one of the look-ahead restore threads in the look-ahead thread pool to use to process said another restore request; and

retrieving, using said another look-ahead restore thread, said another secondary copy from the one or more source secondary storage devices and forward said another secondary copy to the destination system for storage on the one or more destination secondary storage devices.

20. The method of claim 19, further comprising determining, based on a metric associated with said another look-ahead restore thread, that said another look-ahead restore thread is not to be used to process the said another restore request to restore said another secondary copy.