Failover scopes for nodes of a computer cluster

• US 20060080568A1
• Filed: 10/08/2004
• Published: 04/13/2006
• Est. Priority Date: 10/08/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Shrivastava, Sunita, Subbaraman, Chittur P.
• Granted Patent: US 7,451,347 B2
• Time in Patent Office: Days
• US Class Current: 714/4
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: G06F 11/2028 eliminating a faulty processor or activating a spare
• CPC Class Codes: G06F 11/2035 without idle spare hardware

Abstract

A failover scope comprises a node collection in a computer cluster. A resource group (e.g., application program) is associated with one or more failover scopes. If a node fails, its hosted resource groups only failover to nodes identified in each resource group'"'"'s associated failover scope(s), beginning with a first associated failover scope, in order, thereby defining an island of nodes within which a resource group can failover. If unable to failover to a node of a resource group'"'"'s first failover scope, failover is attempted to a node represented in any next associated failover scope, which may require manual intervention. Failover scopes may represent geographic sites, whereby each resource group attempts to failover to nodes within its site before failing over to another site. Failover scopes may be managed by the cluster runtime automatically, e.g., an added node is detectable as belonging to a site represented by a failover scope.

Claims

1. In a computing environment, a method comprising:

defining a failover scope corresponding to selected nodes within a cluster;

associating the failover scope with a resource group; and

failing over the resource group from one node to another node based on the failover scope associated with the resource group.

2. The method of claim 1 wherein defining the failover scope comprises defining at least part of the failover scope via an automatic process.

3. The method of claim 1 wherein defining the failover scope comprises receiving input from an administrator with respect to at least part of the failover scope.

4. The method of claim 1 wherein defining the failover scope comprises defining at least part of the failover scope to correspond to a site.

5. The method of claim 1 further comprising, detecting addition of a new node, and modifying the failover scope to include information corresponding to the new node.

6. The method of claim 1 further comprising associating at least one other failover scope with the resource group.

7. The method of claim 1 further comprising, preventing intersection of nodes between failover scopes associated with the resource group.

8. The method of claim 6 further comprising, maintaining an ordering of failover scopes associated with the resource group such that an attempt is made to failover the resource group to a node in a first failover scope before an attempt is made to failover the resource group a node in any other failover scope.

9. The method of claim 8 wherein the attempt to failover the resource group to a node in a first failover scope is unsuccessful, and further comprising, accessing data that indicates whether manual intervention is necessary before attempting to failover the resource to a node of another failover scope.

10. The method of claim 1 wherein failing over the resource group from one node to another node comprises selecting the other node from among a plurality of candidate nodes in the failover scope.

11. The method of claim 10 wherein selecting the other node from among a plurality of candidate nodes is based on a random selection.

12. The method of claim 10 wherein selecting the other node from among a plurality of candidate nodes is based on meeting at least one criterion.

13. One or more computer-readable media having computer-executable instructions which when executed perform the method of claim 1.

14. In a computing environment, a method comprising:

defining a first failover scope corresponding to a first subset of nodes within a cluster;

defining a second failover scope corresponding to a second subset of nodes within a cluster;

associating the first and second failover scopes with a resource group; and

attempting to failover the resource group from one node to another node of the first failover scope, and if the attempt is unsuccessful with each node of the first failover scope, failing over the resource group to a node of the second failover scope.

15. The method of claim 14 wherein the first and second subsets are non-intersecting.

16. The method of claim 14 further comprising, maintaining ordering information that indicates that the attempt to failover the resource group is made with the first subset of nodes identified within the first failover scope before any other attempt to failover the resource group.

17. The method of claim 14 wherein defining the first and second failover scopes comprises defining at least part of one of the failover scopes via an automatic process.

18. The method of claim 14 wherein defining the first and second failover scopes comprises receiving input from an administrator with respect to at least part of one of the failover scopes.

19. The method of claim 14 wherein defining the first failover scope comprises defining at least part of the first failover scope to correspond to a site.

20. The method of claim 14 further comprising, detecting addition of a new node, and modifying the first failover scope to include information corresponding to the new node.

21. The method of claim 14 further comprising associating a third failover scope with the resource group.

22. The method of claim 14 wherein the attempt to failover the resource group to a node in a first failover scope is unsuccessful, and further comprising, accessing data that indicates whether manual intervention is necessary before failing over the resource to a node of the second failover scope.

23. The method of claim 22 wherein the data indicates that manual intervention is necessary, and further comprising, awaiting manual intervention before failing over the resource to a node of the second failover scope.

24. The method of claim 14 wherein failing over the resource group from one node to another node comprises selecting the other node from among a plurality of candidate nodes in the failover scope.

25. The method of claim 24 wherein selecting the other node from among a plurality of candidate nodes is based on a random selection.

26. The method of claim 24 wherein selecting the other node from among a plurality of candidate nodes is based on meeting at least one criterion.

27. One or more computer-readable media having computer-executable instructions which when executed perform the method of claim 14.

28. In a computing environment, a system comprising:

a plurality of nodes; and

a mechanism running in at least one of the nodes that selects a selected failover scope associated with a resource group when the resource group needs to be failed over from one node to another node, the mechanism attempting to first failover the resource group to a node of the selected failover scope.

29. The system of claim 28 wherein a plurality of failover scopes are associated with the resource group, and the mechanism selects the selected failover scope based on an ordering of the failover scopes.

30. The system of claim 29 wherein the mechanism fails to failover the resource group to the selected failover scope, and wherein the mechanism selects a newly selected failover scope and attempts to next failover the resource group to a node of the newly selected failover scope.

31. The system of claim 29 wherein the mechanism fails to failover the resource group to the selected failover scope, and wherein the mechanism checks data to determine whether another failover scope may be selected for an automatic attempt to failover the resource group to a node of the other failover scope.

32. The system of claim 28 wherein selected failover scope corresponds to a site.

33. One or more computer-readable media having stored thereon a plurality of related data structures, comprising:

a first data structure that includes a set of at least one failover scope, each failover scope associated with a node set identifying at least one node of a cluster;

a second data structure that identifies at least one resource group, at least one identified resource group having an association with at least one failover scope included in the first data structure; and

wherein upon failure of a resource group identified in the second data structure, the second data structure is accessed to select an associated failover scope as a selected failover scope, and the first data structure is accessed to locate the node set corresponding to the selected failover scope such that the resource group may be failed over to a node identified in the selected failover scope.

34. The computer-readable media of claim 33 wherein the resource group identified in the second data structure is associated with at least two failover scopes included in the first data structure.

35. The computer-readable media of claim 34 further comprising data associated with the resource group that indicates whether a failover to a node of a failure scope other than the selected failover scope requires manual intervention.

36. The computer-readable media of claim 33 wherein the resource group identified in the second data structure is associated with first and second failover scopes and wherein the resource group is further associated with information that orders the first and second failover scopes such that the first resource group is the selected resource group.

37. The computer-readable media of claim 36 wherein the first and second resource groups are maintained in the second data structure as a list associated with the identified resource group, and wherein the information that orders the first and second failover scopes comprise an ordering of the failover scopes in the list.