Itinerary based agent mobility including mobility of executable code

• US 6,233,601 B1
• Filed: 11/13/1997
• Issued: 05/15/2001
• Est. Priority Date: 11/14/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Walsh, Thomas C.
• Primary Examiner(s): Dinh, Dung C.
• Application Number:
  US08/969,478
• Time in Patent Office: 1,279 Days
• Field of Search: 709/202, 709/203, 709/201, 709/102
• US Class Current: 709/202
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/4862 the task being a mobile agent, i.e. specifically designed to migrate
• CPC Class Codes: G06F 9/4868 with creation or replication
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

In accordance with the present invention, a mobile agent object executes a first method on a first computer, migrates from the first computer to a second computer, and executes a second method on the second computer. The first and second methods and first and second computers are designated in an itinerary. The agent includes both data and executable code which are serialized for transmission from the first computer to the second computer as data. The data containing the agent is then deserialized in the second computer to regenerate the agent in the form of an object. The executable code portion of the agent can be supplemented with code from a home codebase located on another computer.

Claims

1. In a computer network including at least a first computer and a second computer, an apparatus for performing a task in a second computer, comprising:

a routine that generates a mobile agent object in the first computer, the mobile agent including both data and executable code;

a protocol for transmission of the mobile agent from the first computer to the second computer, wherein execution of the mobile agent in the second computer following such transmission prompts the task to be performed in the second computer; and

an itinerary containing a reference to each destination computer to which the mobile agent is designated to migrate and a reference to a method associated with each respective destination computer reference, the respective method being invoked when the mobile agent is present on the respective destination computer.

2. The apparatus of claim 1 wherein the transmission protocol includes a routine in the first computer for serializing the mobile agent to generate a stream of data therefrom.

3. The apparatus of claim 2 wherein the transmission protocol includes a routine in the second computer for deserializing the stream of bytes to regenerate the mobile agent therefrom.

4. The apparatus of claim 1 wherein the task is data gathering, and wherein the mobile agent is transmitted back to the first computer from the second computer following completion of such data gathering.

5. The apparatus of claim 1 wherein the mobile agent migrates to a plurality of destination computers within the computer network.

6. The apparatus of claim 1 wherein at least one destination computer reference is a Uniform Resource Locator.

7. The apparatus of claim 1 wherein at least a portion of the executable code required for invoking the method is retrieved from a mobile codebase portion of the executable code included in the mobile agent.

8. The apparatus of claim 7 wherein the mobile agent includes a reference to a home codebase located on the first computer, the reference being employed to retrieve required executable code which is not present in the mobile codebase.

9. The apparatus of claim 8 wherein required executable code is sought first in the computer on which the mobile agent is executing, then in the mobile codebase, and finally on the home codebase.

10. The apparatus of claim 8 wherein a new thread is formed for execution of the mobile agent in the destination computer following receipt of the mobile agent, and wherein a security feature prevents the mobile agent from operating outside a scope assigned to such thread.

11. The apparatus of claim 8 wherein the mobile agent further includes sub-objects.

12. The apparatus of claim 1 wherein a persistent local copy of the mobile agent is stored following receipt of the mobile agent, and wherein such copy is overwritten with an updated persistent copy following agent execution.

13. In a computer network including at least a first computer and a second computer, a method for performing a task in a second computer, comprising the steps of:

generating a mobile agent object in the first computer, the mobile agent including both data and executable code;

transmitting the mobile agent from the first computer to the second computer;

receiving the mobile agent in the second computer; and

executing the mobile agent in the second computer in accordance with an itinerary which contains a reference to each destination computer to which the mobile agent is designated to migrate and a reference to a method associated with each respective destination computer reference, the method associated with the second computer being invoked when the mobile agent is present on the second computer.

14. The method of claim 13 including the further step of serializing the mobile agent to generate a stream of data therefrom in the first computer.

15. The method of claim 14 including the further step of deserializing the stream of bytes to regenerate the mobile agent therefrom in the second computer.

16. The method of claim 13 wherein the task is data gathering, and including the further step of transmitting the mobile agent back to the first computer from the second computer following completion of such data gathering.

17. The method of claim 13 including the further step of causing the mobile agent to sequentially migrate to a plurality of destination computers within the computer network.

18. The method of claim 13 including the further step of employing a Uniform Resource Locator as one of the at least one destination computer reference.

19. The method of claim 13 including the further step of retrieving at least a portion of the executable code required for invoking the method from a mobile codebase portion of the executable code included in the mobile agent.

20. The method of claim 19 wherein the mobile agent includes a reference to a home codebase located on the first computer, and including the further step of employing the reference to retrieve required executable code which is not present in the mobile codebase.

21. The method of claim 20 including the further step of searching for required executable code first in the computer on which the mobile agent is executing, then in the mobile codebase, and finally on the home codebase.

22. The method of claim 21 including the further step of forming a new thread in the destination computer for execution of the mobile agent following receipt thereof, and wherein a security feature prevents the mobile agent from operating outside a scope assigned to such thread.

23. The method of claim 21 including the further step of inserting sub-objects into the mobile agent.

24. The method of claim 13 including the further step of storing a persistent local copy of the mobile agent following receipt thereof, and overwriting such copy with an updated persistent copy following agent execution.

25. In a computer network including at least a first computer and a second computer, an apparatus for performing a task in a second computer, comprising:

a routine that generates a mobile agent object in the first computer, the mobile agent including both data and executable code;

a protocol for transmission of the mobile agent from the first computer to the second computer, wherein execution of the mobile agent in the second computer following such transmission prompts the task to be performed in the second computer, at least a portion of the executable code required for execution being retrieved from a mobile codebase portion of the executable code included in the mobile agent; and

a reference to a home codebase located on the first computer, the reference being employed to retrieve required executable code which is not present in the mobile codebase.

26. The apparatus of claim 25 wherein the transmission protocol includes a routine in the first computer for serializing the mobile agent to generate a stream of data therefrom.

27. The apparatus of claim 26 wherein the transmission protocol includes a routine in the second computer for deserializing the stream of bytes to regenerate the mobile agent therefrom.

28. The apparatus of claim 25 wherein the task is data gathering, and wherein the mobile agent is transmitted back to the first computer from the second computer following completion of such data gathering.

29. The apparatus of claim 25 wherein the mobile agent migrates to a plurality of destination computers within the computer network.

30. The apparatus of claim 29 wherein the mobile agent further includes an itinerary containing a reference to each destination computer to which the agent is designated to migrate and a reference to a method associated with each respective destination computer reference, the respective method being invoked when the mobile agent is present on the respective destination computer.

31. The apparatus of claim 30 wherein at least one destination computer reference is a Uniform Resource Locator.

32. The apparatus of claim 25 wherein required executable code is sought first in the computer on which the mobile agent is executing, then in the mobile codebase, and finally on the home codebase.

33. The apparatus of claim 25 wherein a new thread is formed for execution of the mobile agent in the destination computer following receipt of the mobile agent, and wherein a security feature prevents the mobile agent from operating outside a scope assigned to such thread.

34. The apparatus of claim 25 wherein the mobile agent further includes sub-objects.

35. The apparatus of claim 30 wherein a persistent local copy of the mobile agent is stored following receipt of the mobile agent, and wherein such copy is overwritten with an updated persistent copy following agent execution.

48. The apparatus of claim 25, wherein the retrieved required executable code is incorporated into the mobile codebase.

36. In a computer network including at least a first computer and a second computer, a method for performing a task in a second computer, comprising the steps of:

generating a mobile agent object in the first computer, the mobile agent including both data and executable code;

transmitting the mobile agent from the first computer to the second computer;

receiving the mobile agent in the second computer;

retrieving at least a portion of the executable code required for invoking the method from a mobile codebase portion of the executable code included in the mobile agent;

employing a reference to a home codebase located on the first computer to retrieve required executable code which is not present in the mobile codebase; and

executing the mobile agent in the second computer such that the mobile agent prompts the task to be performed in the second computer.

37. The method of claim 36 including the further step of serializing the mobile agent to generate a stream of data therefrom in the first computer.

38. The method of claim 37 including the further step of deserializing the stream of bytes to regenerate the mobile agent therefrom in the second computer.

39. The method of claim 36 wherein the task is data gathering, and including the further step of transmitting the mobile agent back to the first computer from the second computer following completion of such data gathering.

40. The method of claim 36 including the further step of causing the mobile agent to sequentially migrate to a plurality of destination computers within the computer network.

41. The method of claim 40 wherein the mobile agent further includes an itinerary which contains a reference to each destination computer to which the agent is designated to migrate and a reference to a method associated with each respective destination computer reference, and including the further step of invoking the method associated with the respective destination computer when the mobile agent is present on the respective destination computer.

42. The method of claim 41 including the further step of employing a Uniform Resource Locator as one of the at least one destination computer reference.

43. The method of claim 36 including the further step of searching for required executable code first in the computer on which the mobile agent is executing, then in the mobile codebase, and finally on the home codebase.

44. The method of claim 36 including the further step of forming a new thread in the destination computer for execution of the mobile agent following receipt thereof, and wherein a security feature prevents the mobile agent from operating outside a scope assigned to such thread.

45. The method of claim 36 including the further step of inserting sub-objects into the mobile agent.

46. The method of claim 41 including the further step of storing a persistent local copy of the mobile agent following receipt thereof, and overwriting such copy with an updated persistent copy following agent execution.

47. The method claim 36, further comprising the step of:

incorporating the retrieved required executable code into the mobile codebase.