System and method for efficient lock recovery

• US 7,266,722 B2
• Filed: 09/20/2002
• Issued: 09/04/2007
• 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: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Kingsbury, Brent A.
• Primary Examiner(s): Baderman, Scott
• Assistant Examiner(s): LOHN, JOSHUA A
• Application Number:
  US10/251,893
• Publication Number:
  US 20030079155A1
• Time in Patent Office: 1,810 Days
• Field of Search: 714/15, 714/19, 714/27, 714/26, 707/202
• US Class Current: 714/15
• 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;

determining a recovery order for a first lock and a second lock based at least in part on respective levels of exclusion of the first lock and the second lock;

recovering the first lock; and

recovering the second lock;

wherein if the recovery order is determined to be parallel recovering the first lock occurs in parallel to the recovering of the second lock, and determining the lock recovery should be performed includes determining a change has occurred to a lock domain membership associated with a list of nodes participating in lock negotiation within a given lock domain.

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.

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

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.

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 occurs when a node fails.

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

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

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

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

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

determining a lock recovery should be performed;

recovering a first lock; and

recovering a second lock after recovering the first lock;

wherein the second lock is recovered after the first lock at least in part due to the first lock having a higher level of exclusion than the second lock, and determining the lock recovery should be performed includes determining a change has occurred to a lock domain membership associated with a list of nodes participating in lock negotiation within a given lock domain.

16. The method of claim 15, further comprising providing a lock manager.

17. The method of claim 15, wherein the node is a server.

18. The method of claim 15, wherein the node shares a resource with a second node.

19. The method of claim 18, wherein the shared resource is a shared storage.

20. The method of claim 15, wherein the first lock is a write lock.

21. The method of claim 15, wherein the second lock is a read lock.

22. The method of claim 15, wherein the first lock is recovered from a first lock space to a second lock space.

23. The method of claim 15, wherein the determining the lock recovery should be performed includes recognizing a change in a lock domain membership.

24. A system for recovering a lock comprising:

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

recover a first lock;

recover a second lock after recovering the first lock;

wherein the second lock is recovered after the first lock at least in part due to the first lock having 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;

wherein to determine the lock recovery should be performed, the processor determines a change has occurred to a lock domain membership associated with a list of nodes participating in lock negotiation within a given lock domain.

25. 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; and

a processor configured to determine a recovery order for the first lock and the second lock based at least in part on respective levels of exclusion of the first lock and the second lock;

wherein if the recovery order is determined to be parallel recovering the first lock occurs in parallel to the recovering of the second lock, and the first lock and the second lock are recovered when a change has occurred to a lock domain membership associated with a list of nodes participating in lock negotiation within a given lock domain.

26. 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; and

recovering a second lock in the first node;

wherein the second lock is recovered after the first lock at least in part due to the first lock having a higher level of exclusion than the second lock, and the lock domain membership is associated with a list of nodes participating in lock negotiation within a given lock domain.

27. A method for recovering locks comprising:

recognizing a change in membership;

determining a recovery order for a first lock and a second lock based at least in part on respective levels of exclusion of the first lock and the second lock;

providing a first lock space;

providing a second lock space;

recovering the first lock; and

recovering the second lock;

wherein if the recovery order is determined to be parallel recovering the first lock occurs in parallel to the recovering of the second lock, and membership is associated with a list of nodes participating in lock negotiation within a given lock domain.

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

determining a lock recovery should be performed;

recovering a first lock; and

recovering a second lock after recovering the first lock;

wherein the second lock is recovered after the first lock at least in part due to the first lock having a higher level of exclusion than the second lock, and determining the lock recovery should be performed includes determining a change has occurred to a lock domain membership associated with a list of nodes participating in lock negotiation within a given lock domain.