Fast application notification in a clustered computing system

• US 20050038772A1
• Filed: 08/12/2004
• Published: 02/17/2005
• Est. Priority Date: 08/14/2003
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Colrain, Carol
• Granted Patent: US 7,747,717 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2209/5016 Session
• CPC Class Codes: G06F 2209/544 Remote
• CPC Class Codes: G06F 9/5061 Partitioning or combining of resources
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications

Abstract

With fast notification of changes to a clustered computing system, through which a number of events are published for system state changes, applications can quickly recover and sessions can quickly be rebalanced. When a resource associated with a service experiences a change in status, such as a termination or a start/restart, a notification event is immediately published. Notification events contain information to enable subscribers to identify, based on matching a session signature, the particular sessions that are affected by the change in status, and to respond accordingly. This allows sessions to be quickly aborted and ongoing processing to be quickly terminated when a resource fails, and allows fast rebalancing of work when a resource is restarted.

Claims

1. A method for communicating changes about a clustered computing environment that comprises a plurality of interconnected nodes that host server instances, comprising the computer-implemented steps of:

receiving an indication of a status change to a resource associated with work performed in a cluster;

in response to said status change in said cluster, immediately generating first data that identifies said resource and second data indicates a status of said resource;

publishing said first and second data to a set of one or more subscribers; and

wherein said first data is used by a subscriber to identify, based on identification information that is generated in response to establishing a session with said cluster and that identifies a resource associated with said session, one or more sessions with said cluster that are affected by said status change.

2. The method of claim 1, wherein said status of said resource that is identified in said event is one from a group consisting of (a) termination of said resource, (b) starting of said resource, and (c) unable to restart said resource.

3. The method of claim 1, wherein said cluster is a database cluster, and wherein said resource is identified in said first data by identifying said database cluster that is affected by said status change.

4. The method of claim 3, wherein said work is associated with a service, and wherein said resource is further identified in said first data by identifying said service that is affected by said status change.

5. The method of claim 4, wherein said location of said resource is further identified in said first data by identifying an instance and a node that are affected by said status change.

6. The method of claim 3, further comprising the computer-implemented step of:

identifying one or more sessions with said database cluster that are affected by said status change, based on matching said identification information that is associated with said session with said first data that identifies said resource.

7. The method of claim 6, further comprising the computer-implemented step of:

interrupting said one or more sessions.

8. The method of claim 1, wherein said resource is identified in said first data by identifying a node that is affected by said status change.

9. The method of claim 1, wherein said work is associated with a service, and wherein said resource is identified in said first data by identifying that a service has terminated at a particular instance and by identifying said particular instance at which said service has terminated.

10. The method of claim 1, wherein said work is associated with a service, and wherein said resource is identified in said first data by identifying that an entire service has terminated and by identifying said service that has terminated.

11. The method of claim 1, wherein said resource is identified in said first data by identifying that a particular instance has terminated and by identifying said particular instance that has terminated.

12. The method of claim 1, wherein said resource is identified in said first data by identifying that all said instances have terminated and that identifies said cluster with which said instances are associated.

13. The method of claim 1, wherein said work is associated with a service, and wherein said resource is identified in said first data by identifying that a service has started at a particular instance and by identifying said particular instance on which said service has started.

14. The method of claim 13, wherein said resource is identified in said first data by identifying the number of instances that support said service that has started.

15. The method of claim 1, wherein said work is associated with a service, and wherein said resource is identified in said first data by identifying that a service has started on any instance and by identifying said service that has started.

16. The method of claim 15, wherein said resource is identified in said first data by identifying a number of instances that support said service that has started.

17. The method of claim 1, wherein said resource is identified in said first data by identifying that a particular instance has started and by identifying said instance that has started.

18. The method of claim 1, wherein said resource is identified in said first data by identifying that an instance has started and by identifying said cluster with which said instance is associated.

19. The method of claim 1, wherein said resource is identified in said first data by identifying that a node has terminated and by identifying said node that has terminated.

20. The method of claim 1, wherein the step of publishing comprises publishing said first and second data through processes that are not part of clusterware that manages said cluster.

21. The method of claim 1, wherein a subscriber to said first and second data is a connection pool manager that responds to said status change by redistributing, based on said first and second data, connections to said cluster.

22. The method of claim 1, wherein a subscriber to said first and second data is a client application that responds to said status change by requesting, based on said first and second data, redistribution within said cluster of said work that is affected by said status change.

23. The method of claim 1, wherein a subscriber to said first and second data is a batch job that responds to said first and second data by calling for execution of a routine within said cluster based on said status change.

24. The method of claim 1, wherein said work is associated with a service, and wherein said resource is identified in said first data by identifying that said service is not restarting so that subscribing applications are interrupted from retrying to use said service.

25. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

26. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

27. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

28. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

29. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

30. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

31. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

32. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

33. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.

34. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 10.

35. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 11.

36. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 12.

37. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 13.

38. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 14.

39. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 15.

40. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 16.

41. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 17.

42. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 18.

43. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 19.

44. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 20.

45. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 21.

46. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 22.

47. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 23.

48. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 24.

49. A system comprising:

a database cluster comprising a set of server instances hosted by a set of interconnected nodes communicatively coupled to a database;

cluster management software that manages resources in said cluster and distribution and performance of work in said cluster;

a notification system that publishes information about status changes of said resources, for use in identifying, based on identification information that is generated when a session is established with said cluster and that identifies resources associated with said session, one or more sessions with said cluster that are affected by a respective status change; and

wherein each said information about a status change to a resource comprises identification of said resource and a status of said resource.

50. The system of claim 49, wherein said status of said resource that is identified in said information about a status change consists of one from a group consisting of (a) termination of said resource, (b) starting of said resource, and (c) unable to restart said resource.

51. The system of claim 49, wherein said resource that is identified in said information about a status change is associated with at least one from a group consisting of (a) a service, (b) a service member that is executing on a particular instance of said instances, (c) said database cluster, (d) one of said instances, and (e) one of said nodes.