Clustered object state using logical actions

• US 20060271542A1
• Filed: 05/25/2006
• Published: 11/30/2006
• Est. Priority Date: 05/25/2005
• Status: Abandoned Application

• Current Assignee: Orion D. Letizi, Steven T. Harris, Timothy S. Eck
• Original Assignee: Orion D. Letizi, Steven T. Harris, Timothy S. Eck
• Inventors: Letizi, Orion D., Eck, Timothy S., Harris, Steven T.
• Application Number:
  US11/442,524
• Publication Number:
  US 20060271542A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1479 Generic software techniques for error detection or fault masking
• CPC Class Codes: G06F 11/203 using migration
• CPC Class Codes: G06F 16/217 Database tuning G06F16/2282 takes precedence; database performance monitoring G06F11/3409
• CPC Class Codes: G06F 16/24552 Database cache management
• CPC Class Codes: G06F 2209/522 Manager
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57
• CPC Class Codes: G06F 9/45504 Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms
• CPC Class Codes: G06F 9/544 Buffers; Shared memory; Pipes

Abstract

Technology for sharing data among multiple virtual machines in a cluster of virtual machines is disclosed. Each virtual machine identifies “managed” objects of an instance of an application running at the virtual machine. Operations performed by an instance of one application which affect the state of managed objects are detected and distributed. Each virtual machine in the cluster represents object data using a different locally generated object identifier. The virtual machine detects operations, such as method calls, which are performed by the application and which affect the states of the managed objects. The virtual machine then communicates information identifying the operations to the central manager for use in providing a local representation of the states of the managed objects.

Claims

1. A computer-implemented method for maintaining consistent data at different virtual machines, comprising:

creating a transaction including a logical operation affecting a state of a local instance of a managed object at a first virtual machine; and

communicating the transaction to at least a second virtual machine having an instance of the managed object.

2. The computer implemented method of claim 1 wherein the step of communicating is performed by a central manager.

3. The computer-implemented method of claim 1, wherein the transaction comprises at least one action performed by an application in the first virtual machine on a managed object.

4. The computer-implemented method of claim 3, wherein a log including a series of transactions is communicated.

5. The computer-implemented method of claim 4 wherein the log is applied to a central representation of the managed objects maintained on a central manager.

6. The computer-implemented method of claim 2, wherein:

the central manager creates a central representation of the states of all managed objects and communicates the state to the second virtual machine.

7. The computer-implemented method of claim 6, wherein:

the central manager creates a log of actions to create a local instance of the managed object on the second virtual machine when no managed objects exist on the second virtual machine.

8. The computer-implemented method of claim 6, wherein the second virtual machine replays the operation on a local instance of the managed objects at said second virtual machine.

9. The computer-implemented method of claim 2, wherein:

the first virtual machine and the central manager each maintain a respective local representation of the managed objects according to respective locally generated object identifiers.

10. The computer-implemented method of claim 1, wherein:

the first virtual machine, central manager and second virtual machine each maintain a respective local representation of the states of the managed objects according to respective locally generated object identifiers.

11. The computer-implemented method of claim 1, wherein:

the step of creating is performed at the first virtual machine;

the method includes transmitting the transaction to a central manager; and

the step of communicating is performed by the central manager.

12. The computer-implemented method of claim 1 wherein a plurality of virtual machines are provided and wherein the step of communicating includes providing ones of said objects in the logical representation to a subset of said virtual machines.

13. A computer-implemented method for maintaining consistent data at different virtual machines, comprising:

receiving information including a logical action on at least one managed object by a first instance of an application running at a first virtual machine; and

communicating the logical action to at least a second virtual machines.

14. The computer-implemented method of claim 13 wherein the step of receiving includes receiving information from a first virtual machine on which a first instance of an application is running, and applying the information to a central representation of the managed object.

15. The computer-implemented method of claim 14, wherein the information comprises a series of logical actions.

16. The computer-implemented method of claim 14, wherein:

the information received comprises a series of transactions comprising logical actions which are performed while the first instance of the application accesses at least one of the managed objects.

17. The computer-implemented method of claim 14, wherein:

the logical action provided to at least said second virtual machine includes a set of logical actions to update a local instance of the managed objects at the second virtual machine.

18. The computer-implemented method of claim 14, further including the step of updating the central representation of the states of the managed objects as additional information identifying additional logical actions is received from a first virtual machine.

19. The computer-implemented method of claim 18, further comprising:

using the central representation of the states of the managed objects to generate a log of transactions; and

wherein the step of communicating includes providing the log of logical actions to the second virtual machine.

20. A computer-implemented method for maintaining consistent data at different virtual machines, comprising:

receiving one or more logical actions affecting the state in one or more managed objects in a first virtual machine; and

applying the logical actions to update a local instance of managed objects at the first virtual machine.

21. The computer-implemented method of claim 20, wherein:

the logical actions include operations identified by the first virtual machine of the states of the managed objects.

22. The computer-implemented method of claim 20, wherein the logical actions and provided by a central manager.

23. The computer-implemented method of claim 22 wherein the central manager maintains a central representation of the states of the managed objects.