Concurrency classes for shared file systems

• US 20040111422A1
• Filed: 12/10/2002
• Published: 06/10/2004
• Est. Priority Date: 12/10/2002
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Devarakonda, Murthy V., Robinson, John T.
• Granted Patent: US 7,254,578 B2
• Time in Patent Office: Days
• US Class Current: 707/100
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A method, apparatus and computer product wherein means and mechanisms are provided whereby, in a distributed or clustered shared file system, (1) concurrency classes may be defined specifying granularity of locking, whether locks are cached, and whether modified data is written-through at the completion of updates, (2) certain files, file types, or files and/or file types as used by given applications or classes of applications, may be associated with concurrency classes, and (3) for each usage of a file by an application, the associated concurrency class determines a policy for choosing specific concurrency and coherency control mechanisms to be used for accessing the given file.

Claims

1. In a distributed computer system with a shared file system, a method for managing concurrency and coherency of files, comprising:

defining a number of concurrency classes;

specifying files and applications to be associated with a concurrency class; and

determining locking and caching policies to be used for files and applications in accordance with an associated concurrency class.

2. The method as recited in claim 1, further comprising determining write-through policies in accordance with said associated concurrency class.

3. The method as recited in claim 2, wherein a concurrency class specifies granularity of locking, whether locks are cached, and whether cached data is written-through to a file server.

4. The method as recited in claim 3, wherein the concurrency class further specifies lifetime of cached locks.

5. The method as recited in claim 2, including a default concurrency class in which granularity is at the file level, a cache lock is used, and there is no write-through.

6. The method as recited in claim 2, wherein a concurrency table is accessed to determine locking and caching policies to be used for files and applications.

7. The method as recited in claim 6, further comprising updating the concurrency table with a new concurrency class.

8. The method as recited in claim 2, further comprising defining an association between an item to be processed and a concurrency class.

9. The method as recited in claim 8, wherein the items processed comprise at least one of files, file types, files and/or file types, specified applications, and classes of applications.

10. The method as recited in claim 9, wherein an association table is accessed to determine said association.

11. The method as recited in claim 10, further comprising adding new associations to said association table.

12. The method as recited in claim 8, wherein when no association is defined for an item, a default concurrency class is used.

13. The method as recited in claim 8, wherein a factor to be considered in defining said association is an owner of the item, and a relationship between a party accessing the item and the owner.

14. The method as recited in claim 8, wherein a factor to be considered in defining said association is a party accessing the item, where a party is identified by a user identification and a group identification.

15. The method as recited in claim 1, wherein a concurrency class specifies granularity of locking, and whether locks are cached.

16. The method as recited in claim 15, wherein the concurrency class further specifies lifetime of cached locks.

17. The method as recited in claim 1, including a default concurrency class in which granularity is at the file level, and a cache lock is used.

18. The method as recited in claim 1, wherein a concurrency table is accessed to determine locking and caching policies to be used for files and applications.

19. The method as recited in claim 18, further comprising updating the concurrency table with a new concurrency class.

20. The method as recited in claim 1, further comprising defining an association between an item to be processed and a concurrency class.

21. The method as recited in claim 20, wherein the items processed comprise at least one of files, file types, files and/or file types, specified applications, and classes of applications.

22. The method as recited in claim 20, wherein an association table is accessed to determine said association.

23. The method as recited in claim 22, further comprising adding new associations to said association table.

24. The method as recited in claim 20, wherein when no association is defined for an item, a default concurrency class is used.

25. The method as recited in claim 20, wherein a factor to be considered in defining said association is an owner of the item, and a relationship between a party accessing the item and the owner.

26. The method as recited in claim 20, wherein a factor to be considered in defining said association is a party accessing the item, where a party is identified by a user identification and a group identification.

27. A computer system having at least one file server and a plurality of clients served by said at least one file server, wherein file provided by said at least one file server are shared by said clients, said system comprising:

a file manager for managing coherency and concurrency of the files, said file manager including;

a storage for defining a number of concurrency classes, and for specifying files and applications to be associated with a concurrency class; and

apparatus for execution of locking and caching policies to be used for files and applications in accordance with an associated concurrency class.

28. The system as recited in claim 27, wherein said storage further defines write-through policies in accedence with said associated concurrency class.

29. The system as recited in claim 28, wherein a concurrency class specifies granularity of locking, whether locks are cached, and whether cached data is written-through to a file server.

30. The system as recited in claim 29, wherein the concurrency class further specifies lifetime of cached locks.

31. The system as recited in claim 28, wherein said storage includes a default concurrency class in which granularity is at the file level, a cache lock is used and there is no write-through.

32. The system as recited in claim 28, wherein said storage comprises a concurrency table which is accessed to determine locking and caching policies to be used for files and applications.

33. The system as recited in claim 32, further comprising a system management application—

for providing access to said storage for updating the concurrency table with a new concurrency class.

34. The system as recited in claim 28, further comprising additional storage for storing an association between an item to be processed and a concurrency class.

35. The system as recited in claim 34, wherein the items processed comprise at least one of files, file types, files and/or file types, specified applications, and classes of applications.

36. The system as recited in claim 28, comprising a system management application for accessing an association table to determine said association.

37. The system as recited in claim 28, further comprising a system management application for adding new associations to said association table.

38. The system as recited in claim 28, wherein when no association is defined for an item, a default concurrency class is specified.

39. The system as recited in claim 34, wherein a factor to be considered in defining said association is an owner of the item, and a relationship between a party accessing the item and the owner.

40. The system as recited in claim 34, wherein a factor to be considered in defining said association is a party accessing the item, where a party is identified by a user identification and a group identification.

41. The system as recited in claim 27, wherein a concurrency class specifies granularity of locking, and whether locks are cached.

42. The system as recited in claim 41, wherein the concurrency class further specifies lifetime of cached locks.

43. The system as recited in claim 27, including a default concurrency class in which granularity is at the file level, and a cache lock is used.

44. The system as recited in claim 27, comprising a concurrency table which is accessed to determine locking and caching policies to be used for files and applications.

45. The system as recited in claim 44, further comprising a system management application for updating the concurrency table with a new concurrency class.

46. The system as recited in claim 27, further comprising additional storage for storing an association between an item to be processed and a concurrency class.

47. The system as recited in claim 46, wherein the items processed comprise at least one of files, file types, files and/or file types, specified applications, and classes of applications.

48. The system as recited in claim 46, comprising a system management application for accessing an association table to determine said association.

49. The system as recited in claim 48, further comprising a system management application for adding new associations to said association table.

50. The system as recited in claim 46, wherein when no association is defined for an item, a default concurrency class is specified.

51. The system as recited in claim 46, wherein a factor to be considered in defining said association is an owner of the item, and a relationship between a party accessing the item and the owner.

52. The system as recited in claim 46, wherein a factor to be considered in defining said association is a party accessing the item, where a party is identified by a user identification and a group identification.

69. The article of manufacture as recited in claim 49, wherein the code for determining locking and caching policies specifies a default concurrency class in which granularity is at the file level, and a cache lock is used.

53. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing a computer to manage concurrency and coherency of files, said computer readable program code comprising:

code for defining a number of concurrency classes;

code for specifying files and applications to be associated with a concurrency class; and

code for determining locking and caching policies to be used for files and applications in accordance with an associated concurrency class.

54. The article of manufacture as recited in claim 53, further comprising code for determining write-through policies in accordance with said associated concurrency class.

55. The article of manufacture as recited in claim 54, wherein the code for determining locking and caching policies specifies granularity of locking, whether locks are cached, and whether cached data is written-through to a file server.

56. The article of manufacture as recited in claim 55, wherein the code for determining locking and caching policies further specifies lifetime of cached locks.

57. The article of manufacture as recited in claim 54, including a default concurrency class in which granularity is at the file level, a cache lock is used, and there is no write-through.

58. The article of manufacture as recited in claim 54, wherein said code for determining locking and caching policies comprises a concurrency table.

59. The article of manufacture as recited in claim 58, further comprising code for updating the concurrency table with a new concurrency class.

60. The article of manufacture as recited in claim 54, further comprising code for defining an association between an item to be processed and a concurrency class.

61. The article of manufacture as recited in claim 60, wherein the computer program code includes code for processing items which comprise at least one of files, file types, files and/or file types, specified applications, and classes of applications.

62. The article of manufacture as recited in claim 61, wherein the code for defining an association is an association table.

63. The article of manufacture as recited in claim 60, further comprising code for adding new associations to said association table.

64. The article of manufacture as recited in claim 60, wherein when no association is defined for an item, the computer readable program code defines a default concurrency class.

65. The article of manufacture as recited in claim 60, further comprising code for considering an owner of the item, and a relationship between a party accessing the item and the owner, in defining said association.

66. The article of manufacture as recited in claim 60, further comprising code for considering a party accessing the item, where a party is identified by a user identification and a group identification, in defining said association.

67. The article of manufacture as recited in claim 53, wherein the code for determining locking and caching policies specifies granularity of locking, and whether locks are cached.

68. The article of manufacture as recited in claim 67, further comprising code for specifying a lifetime of cached locks.

70. The article of manufacture as recited in claim 53, wherein the code for determining locking and caching policies comprises a concurrency table.

71. The article of manufacture as recited in claim 70, further comprising code for updating the concurrency table with a new concurrency class.

72. The article of manufacture as recited in claim 53, further comprising code for defining an association between an item to be processed and a concurrency class.

73. The article of manufacture as recited in claim 72, wherein the computer readable program code includes code for processing items which comprise at least one of files, file types, files and/or file types, specified applications, and classes of applications.

74. The article of manufacture as recited in claim 72, wherein the code for defining an association is an association table.

75. The article of manufacture as recited in claim 74, further comprising code for adding new associations to said association table.

76. The article of manufacture as recited in claim 72, wherein when no association is defined for an item, the computer readable program code defines a default concurrency class.

77. The article of manufacture as recited in claim 72, further comprising code for considering an owner of the item, and a relationship between a party accessing the item and the owner, in defining said association.

78. The article of manufacture as recited in claim 72, further comprising code for considering a party accessing the item, where a party is identified by a user identification and a group identification, in defining said association.

79. A program storage device usable by a computer, comprising, in combination:

the article of manufacture as recited in claim 53;

and

apparatus for reading the computer readable program code on said article of manufacture.