System and method for efficient lock recovery

• US 20030079155A1
• Filed: 09/20/2002
• Published: 04/24/2003
• Est. Priority Date: 09/21/2001
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: PolyServe, Inc. (HP Inc.)
• Inventors: Kingsbury, Brent A.
• Granted Patent: US 7,266,722 B2
• Time in Patent Office: Days
• US Class Current: 714/2
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system and method are disclosed for providing a system and method for an efficient lock recovery. In one embodiment of the present invention, a multiple node networked system shares a resource such a shared storage. Among various other aspects of the present invention, when there is a change, such as a server failure, that prompts a recovery, the recovery can be performed in parallel among the nodes. A further aspect of an embodiment of the present invention includes recovering a lock with a higher level of exclusion prior to another lock with a lower level of exclusion.

Claims

1. A method for recovering locks comprising:

determining a lock recovery should be performed;

recovering a first lock;

recovering a second lock;

wherein recovering the first lock occurs approximately in parallel to the recovering of the second lock.

7. The method of claim 1, further comprising recovering a third lock after recovering the second lock, wherein the second lock has a higher level of exclusion than the third lock.

8. The method of claim 1, further comprising recovering a third lock after recovering the second lock, wherein the second lock is a write lock and the third lock is a read lock.

9. The method of claim 1, wherein the first lock is recovered from a first lock space to a second lock space.

10. The method of claim 1, wherein the determining the lock recovery should be performed includes recognizing a change in a lock domain membership.

11. The method of claim 1, wherein the determining the lock recovery should be performed occurs when a node fails.

12. The method of claim 1, wherein the determining the lock recovery should be performed occurs when a node is added.

13. The method of claim 1, wherein the determining the lock recovery should be performed occurs when a shared resource fails.

14. The method of claim 1, wherein the determining the lock recovery should be performed occurs when a network interconnect fails.

15. The method of claim 1, wherein the determining the lock recovery should be performed occurs when a shared resource is added.

2. The method of claim 1, further comprising providing a first lock manager and a second lock manager.

3. The method of claim 1, wherein the first lock is recovered in a first node and the second lock is recovered in a second node.

5. The method of claim 3, wherein the first node and the second node share a resource.

6. The method of claim 3, wherein the shared resource is a shared storage.

4. The method of claim 3, wherein the first node is a server.

16. A method for recovering a lock in a node comprising:

determining a lock recovery should be performed;

recovering a first lock;

recovering a second lock after recovering the first lock;

wherein the first lock is of a higher level of exclusion than the second lock.

17. The method of claim 16, further comprising providing a lock manager.

18. The method of claim 16, wherein the node is a server.

19. The method of claim 16, wherein the node shares a resource with a second node.

20. The method of claim 19, wherein the shared resource is a shared storage.

21. The method of claim 16, wherein the first lock is a write lock.

22. The method of claim 16, wherein the second lock is a read lock.

22-1. A system for recovering locks comprising:

a first node configured to recover a first lock;

a second node configured to recover a second lock;

a resource shared by the first and second nodes;

wherein recovering the first lock occurs approximately in parallel to the recovering of the second lock.

23. The method of claim 16, wherein the first lock is recovered from a first lock space to a second lock space.

23-2. A method for recovering locks comprising:

providing a lock manager in a first node;

providing a lock manager in a second node;

recognizing a change in a domain lock membership;

recovering a first lock in the first node;

recovering a second lock in the first node;

wherein the first lock is of a higher level of exclusion than the second lock.

24. The method of claim 16, wherein the determining the lock recovery should be performed includes recognizing a change in a lock domain membership.

24-3. A method for recovering locks comprising:

recognizing a change in membership;

providing a first lock space;

providing a second lock space;

recovering a lock;

recovering a second lock;

wherein recovering the first lock occurs approximately in parallel to the recovering of the second lock.

25. A system for recovering a lock comprising:

a processor configured to determine whether a lock recovery should be performed;

recovering a first lock;

recovering a second lock after recovering the first lock;

wherein the first lock is of a higher level of exclusion than the second lock; and

a memory coupled to the processor, wherein the memory is configured to provide instructions to the processor.

25-4. A computer program product for recovering locks, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

determining a lock recovery should be performed;

recovering a first lock;

recovering a second lock after recovering the first lock;

wherein the first lock is of a higher level of exclusion than the second lock.