Multiple machine architecture with overhead reduction

• US 8,209,393 B2
• Filed: 01/23/2008
• Issued: 06/26/2012
• Est. Priority Date: 10/25/2005
• Status: Active Grant

• Current Assignee: Waratek Limited (Waratek Holdings Ltd.)
• Original Assignee: Waratek Pty Limited
• Inventors: Holt, John M.
• Primary Examiner(s): Hamza, Faruk
• Assistant Examiner(s): AILES, BENJAMIN A
• Application Number:
  US12/011,216
• Publication Number:
  US 20080189385A1
• Time in Patent Office: 1,616 Days
• Field of Search: 709/214, 711/100, 711/147, 711/148, 711/154
• US Class Current: 709/214
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

A multiple computer environment is disclosed in which an application program executes simultaneously on a plurality of computers (M1, M2, . . . Mn) interconnected by a communications network and in which the local memory of each computer is not maintained substantially the same by updating in due course. An address table mechanism is provided to permit access to an asset, object, or structure (i.e., memory location) for the purpose of updating, for example. Not all computers have the same memory, so it is not necessary for all computers to be updated.

Claims

1. A method of maintaining a replication table in a multiple computer system, the method comprising:

providing a plurality of computers each including a local processor and a local updateable memory coupled with the local processor including a first computer and a second computer interconnected via a communications link or network operating in a replicated shared memory arrangement,

classifying the updateable memory locations or values of said updateable memories into a first category of updateable memory locations each of which is replicated on two or more of said multiple computers and a second category of updateable memory locations each of which is present only in the specific one of said multiple computers in which each said second category updateable memory location is physically located, and

maintaining a replication table listing or recording the ones of said multiple computers on which a said first category updateable memory location is replicated,

wherein all memory reads are satisfied locally in each of the plurality of computers by reading replicated updateable memory locations present in each independent local memory of each computer of the plurality of computers.

2. The method of claim 1, further comprising:

maintaining one said replication table for each said first category memory location.

3. The method of claim 2, further comprising:

maintaining one said replication table for a plurality of first category memory locations.

4. The method of claim 3, further comprising:

maintaining one said replication table for each plurality of first category memory locations of potentially multiple pluralities.

5. A method as in claim 3, wherein said plurality of first category memory locations comprise plural memory locations of a related set of memory locations.

6. A method as in claim 5, wherein said related set of memory locations comprise an array of memory locations.

7. A method as in claim 6, wherein said array of memory locations comprise an array data structure.

8. A method as in claim 5, wherein said related set of memory locations comprise memory locations of an object or class.

9. A method as in claim 8, wherein said memory locations of an object or class comprise object fields or variables, or class fields or variables.

10. The method of claim 1, further comprising:

maintaining multiple said replication tables, one in each of said multiple computers.

11. The method of claim 1, further comprising:

maintaining multiple said replication tables, one of each said multiple tables in each of said multiple computers.

12. The method of claim 1, further comprising:

maintaining multiple said replication tables in each of said multiple computers.

13. The method of claim 1, further comprising:

maintaining one said replication table, for all said multiple computers on a further server computer.

14. A method as in claim 1, wherein said first category memory locations of a said computer do not access or refer to any second category memory locations of the same computer.

15. A method as in claim 14, wherein said access includes memory addresses of said second category memory locations.

16. A method as in claim 14, wherein said access includes pointers, references, handles, or links to or of said second category memory locations.

17. A method as in claim 1, wherein said memory locations comprise one or more objects.

18. A method as in claim 1, wherein said memory locations comprise one or more classes.

19. A method as in claim 1, wherein said memory locations comprise one or more object fields or one or more class fields.

20. A method as in claim 1, wherein said memory locations comprise one or more data structures.

21. A method as in claim 1, wherein said memory locations comprise one or more array data structures.

22. A method as in claim 1, wherein said memory locations comprise elements of one or more array data structures.

23. A method as in claim 1, wherein said memory locations comprise libraries, linked libraries, or dynamically linked libraries.

24. The method of claim 1, further comprising:

maintaining multiple replication tables of said first category memory locations, one in each of said plurality of computers, where each said replication table of each one of said plurality of computers lists or records first category memory locations replicated on a same one of said plurality of computers.

25. The method of claim 24, wherein each said replication table of each one of said plurality of computers does not list or record first category memory locations which are not replicated on the same one of said plurality of computers.

26. The method of claim 1, further comprising:

maintaining one said replication table for each said first category memory location, on each one of said multiple computers on which said first category memory location is replicated.

27. The method of claim 1, further comprising:

maintaining multiple said replication tables for each said first category memory location, one in each of said multiple computers on which said first category memory location is replicated.

28. The method of claim 1, further comprising:

maintaining one said replication table for a plurality of said first category memory locations, on each one of said multiple computers on which said plurality of first category memory locations are replicated.

29. The method of claim 1, further comprising:

maintaining multiple said replication table for a plurality of said first category memory location, one in each of said multiple computers on which said plurality of first category memory locations are replicated.

30. The method of claim 1, further comprising:

not maintaining a replication table of a first category memory location on ones of said multiple computers in which said first category memory location is not replicated.

31. The method of claim 1, further comprising:

not maintaining a replication table for a plurality of first category memory locations on ones of said multiple computers in which said plurality of first category memory locations are not replicated.

32. A method as in claim 28, wherein said plurality of first category memory locations comprise plural memory locations of a related set of memory locations.

33. A method as in claim 32, wherein said related set of memory locations comprise an array of memory locations.

34. A method as in claim 33, wherein said array of memory locations comprise an array data structure.

35. A method as in claim 32, wherein said replicated set of memory locations comprise memory locations of an object or class.

36. A method as in claim 35, wherein said memory locations of an object or class, comprise object fields or variables, or class fields or variables.

37. The method of claim 1, further comprising:

substantially simultaneously updating said first category memory locations of the other ones of said computers with any changes made to a first category memory location of any one of said computers.

38. The method of claim 37, further comprising:

utilizing said replication table listing to determine which ones of said multiple computers are to be said substantially simultaneously updated.

39. The method of claim 1, further comprising:

substantially simultaneously updating said first category memory locations of the other ones of said computers with any changes made to a first category memory location of any one of said computers;

utilizing said replication table listing to determine which ones of said multiple computers are to be said substantially simultaneously updated; and

not updating said second category memory locations of the other ones of said computers with any changes made to a second category memory location of any one of said computers.

40. A method as in claim 39, wherein said substantially simultaneous updating includes updating a first category memory locations of the other ones of said computers on which said first category memory locations is replicated, with any changes made to said first category memory locations of any one of said computers.

41. A method as in claim 39, wherein said substantially simultaneous updating excludes updating said first category memory locations of the other ones of said computers on which said first category memory locations is not replicated.

42. The method of claim 1, further comprising performing the classification into first and second categories including:

classifying said the memory locations or values of said local memories into the first category of memory locations each of which is replicated on two or more computers of said multiple computers; and

classifying said local memories into a second category of memory locations each of which is present only in the specific one of said multiple computers in which each said second category of memory location is physically located.

43. The method of claim 1, wherein said local memory of each said computer are independent of said local memory of each other computer.

44. The method of claim 1, wherein each of said local processors may only access said local memory of an associated computer in which a respective local processor is located.

45. A method as in claim 1, wherein at least a first application program written to operate on a single one of said computers, is operating substantially simultaneously on different ones of said multiple computers.

46. The method of claim 45, wherein said application program operating substantially simultaneously on each of said different ones of said computers may only access an associated local memory of an associated computer.

47. The method of claim 46, wherein said access is satisfied by said local memory of an associated computer independently of a local memory associated with any other computer.

48. The method of claim 46, wherein said access includes reading or writing content or values stored or resident within said local memory of an associated computer.

49. The method of claim 47, wherein said access includes reading or writing content or values stored or resident within said local memory of the associated computer.

50. A method as in claim 46, wherein said access is restricted to reading or writing content or values stored or resident within said local memory of the associated computer.

51. The method of claim 47, wherein said access is restricted to reading or writing content or values stored or resident within said local memory of the associated computer.

52. The method of claim 46, wherein said access includes reading or writing content or values of real or virtual memory addresses of or resident within said memory of the associated computer.

53. The method of claim 47, wherein said access includes reading or writing content or values of real or virtual memory addresses of or resident within said local memory of the associated computer.

54. The method of claim 48, wherein said access includes reading or writing content or values of real or virtual memory addresses of or resident within said local memory of the associated computer.

55. The method of claim 46, wherein said access is restricted to reading or writing content or values of real or virtual memory addresses of or resident within said local memory of the associated computer.

56. The method of claim 47, wherein said access is restricted to reading or writing content or values of real or virtual memory addresses of or resident within said local memory of the associated computer.

57. The method of claim 48, wherein said access is restricted to reading or writing content or values of real or virtual memory addresses of or resident within said local memory of the associated computer.

58. The method of claim 46, wherein at least one memory location or memory value of said application program is substantially similarly replicated in said local memory of said different ones of said multiple computers.

59. The method of claim 55, wherein said substantially similarly replicated memory locations or values are stored non-identically in respective memories of said different ones of said multiple computers.

60. The method of claim 56, wherein said substantially similarly replicated memory locations or values are updated through in-due-course updating to remain substantially similar upon occasion of any one of said plurality of computers simultaneously operating said application program modifying, or causing to be modified, a value or content of said substantially similarly replicated memory location or memory value.

61. A method as in claim 60, wherein said in-due-course updating provides that said replicated memory locations are updated to remain substantially similar upon occasion of any one of said computers simultaneously operating said application program causing modification of the contents of said replicated memory location.

62. The method of claim 60, wherein each said substantially similarly replicated memory location or value of each one of said multiple computers is identified with a substantially similar identifier.

63. The method of claim 1, wherein:

said local memory of each said computer are independent of said local memory of each other computer;

each of said local processors may only access an associated local memory of an associated computer in which the respective local processor is located;

at least a first application program written to operate on a single one of said computers is operating substantially simultaneously on different ones of said multiple computers;

said application program, operating substantially simultaneously on each of said different ones of said computers, may only access the associated local memory of the associated computer;

said access is satisfied by the associated local memory of the associated computer independently of an associated local memory of any other computer;

said access includes reading or writing content or values stored or resident within said associated local memory of the associated computer, or said access is restricted to reading or writing content or values stored or resident within said associated local memory of the associated computer;

said access includes reading or writing content or values of real or virtual memory addresses of or resident within associated local memory of the associated computer, or said access is restricted to reading or writing content or values of real or virtual memory addresses of or resident within said associated local memory of the associated computer;

at least one memory location or memory value of said application program is substantially similarly replicated in each of said local memories of said different ones of said multiple computers;

said substantially similarly replicated memory location or value are stored non-identically in respective local memories of said different ones of said multiple computers;

said substantially similarly replicated memory locations or values are updated through in-due-course updating to remain substantially similar upon occasion of any one of said plurality of computers simultaneously operating said application program modifying, or causing to be modified, the value or content of said substantially similarly replicated memory location or memory value;

said in-due-course updating provides that said replicated memory locations are updated to remain substantially similar upon occasion of any one of said computers simultaneously operating said application program causing modification of the contents of said replicated memory location; and

wherein each said substantially similarly replicated memory location or value of each one of said multiple computers is identified with a substantially similar identifier.

64. The method of claim 1, further comprising:

maintaining multiple replication tables of first category memory locations, one in each of said multiple computers, where each said replication table of each one of said multiple computers lists or records first category memory locations replicated on the same one of said multiple computers; and

substantially simultaneously updating said first category memory locations of the other ones of said computers with any changes made to a first category memory location of any one of said computers.

65. An article of manufacture comprising a computer program stored on a non-transitory computer readable memory device and comprising instructions which, when executed on a computer, perform in at least one single computer capable of interoperating with at least one other computer coupled to at least one said single computer at least intermittently via a communications network to form a multiple computer system having a plurality of computers wherein each computer has a local updateable memory and the multiple computer system operating in a replicated shared memory arrangement, said instructions when executed further comprising a method of classifying each said local updateable memory, said method comprising:

classifying memory locations or values of each of said local memories into a first category of updateable memory locations, each of which is replicated on two or more computers of said multiple computers;

classifying each of said local memories into a second category of updateable memory locations each of which is present only in specific ones of said multiple computers in which each said second category of memory location is physically located; and

maintaining a replication table listing or recording the ones of said multiple computers on which a said first category updateable memory location is replicated.