System for providing synchronization between a local area network and a distributing computer environment

• US 5,978,813 A
• Filed: 09/25/1995
• Issued: 11/02/1999
• Est. Priority Date: 09/25/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Foltz, Richard C., Lin, Sy Long, Meegan, John Vincent, Wadood, Syed Abdul
• Primary Examiner(s): Harrell, Robert B.
• Assistant Examiner(s): Coulter, Kenneth R.
• Application Number:
  US08/533,296
• Time in Patent Office: 1,499 Days
• Field of Search: 395/200.09, 395/200.01, 395/619, 707/201
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A database synchronization system for synchronizing a plurality of local databases in a plurality of distributed computing systems is disclosed. The plurality of distributed computing systems form a distributed computing environment (DCE). The synchronization system includes a system server, a registry database, coupled to the system server, a local area network (LAN) synchronization server, coupled to the system server, a LAN server synchronization library, coupled to the system server, and a LAN server, coupled to the LAN synchronization server and selected ones of the plurality distributed computing systems forming a LAN. Synchronization between the LAN and the DCE registry occurs when registry modifications in the registry database affecting at least one of the plurality of local LAN databases invokes the LAN server synchronization library to synchronize the affected database. The synchronization system utilizes a registry database coupled to each of the local databases. A primary replica is coupled to the registry database that synchronizes each local database within the DCE with the registry database. A secondary replica is then coupled to the primary replica, that synchronizes at least one local area network (LAN) server that includes selected ones of the plurality of computing systems and their respective databases with the registry database.

Claims

1. In a plurality of distributed computing systems, each having a local database, forming a distributed computing environment (DCE), a database synchronization system for synchronizing the plurality of local databases comprising:

a DCE system server;

a DCE registry database, coupled to the system server;

a local area network (LAN) synchronization server, coupled to the system server, for transmitting updates from one of said local database to a LAN server coupled to said local LAN synchronization server;

a LAN server synchronization library, coupled to the system server;

said LAN server, coupled to the LAN synchronization server and selected ones of the plurality of distributed computing systems forming a LAN, wherein registry modifications in the registry database affecting at least one of the plurality of local LAN databases invokes the LAN server synchronization library to synchronize the affected database.

2. The database synchronization system according to claim 1 wherein the system server further includes means for determining whether the LAN synchronization library is present and active.

3. The database synchronization system according to claim 1 wherein the LAN server synchronization library serves as a filter and queue for updates for the LAN server.

4. The database synchronization system to claim 1 wherein the LAN synchronization server accepts event notifications from the system server and supervises transmissions to the local databases.

5. The database synchronization system according to claim 4 wherein the LAN synchronization server maintains a list of LAN local databases that are allowed to register with the system server.

6. The database synchronization system according to claim 1 wherein the LAN synchronization server retrieves all user and group information belonging to its associated LAN from each local database within the distributed computing environment and synchronizes the local databases in each registry within the DCE.

7. The database synchronization system according to claim 6 wherein the system server further includes callout means that is invoked to provide updates to the local registry databases within the DCE.

8. The database synchronization system according to claim 1 wherein the system server runs either as a primary replica or as a secondary replica.

9. The database synchronization system according to claim 8 wherein the system server further comprises initialization means for generating shared memory objects for communicating with the LAN synchronization server.

10. The database synchronization system according to claim 8 wherein the system server is running as a primary replica and a first registry object is placed within a stub database and given a designated sequence number such that the sequence number of a next registry update is one greater than the previous update.

11. The database synchronization system according to claim 8 wherein the system server is running as a secondary replica and receives the entire registry database of the DCE from a primary replica and establishes a propagation queue assigning a first propagation having a given sequence number wherein additional propagations are increased by one for each subsequent propagation for registry updates.

12. The database synchronization system according to claim 1 wherein the LAN synchronization library includes an in service state for allowing callouts to add updates to a log file and update queue.

13. The database synchronization system according to claim 1 wherein the LAN synchronization library includes an initialization state when a secondary replica receives a bulk propagation update from a primary replica and does not process any updates during the receiving stage.

14. The database synchronization system according to claim 1 wherein the LAN synchronization library includes an error state when a callout fails to add an update to a log file or an update queue.

15. The database synchronization system according to claim 1 wherein the LAN synchronization library maintains a persistent copy of all valid LAN server updates received from the system server in an update log file.

16. The database synchronization server according to claim 1 further comprising means for providing security within the DCE.

17. A synchronization system for use in a distributed computing environment (DCE), comprising:

a registry database coupled to each of a plurality of local DCE databases within each computing system within the DCE;

a primary replica, coupled to the registry database, that synchronizes each of said plurality of local DCE databases within the DCE with the registry database, wherein each of said plurality of DCE databases is synchronized by the primary replica; and

a secondary replica, coupled to the primary replica, that synchronizes at least one local area network (LAN) server comprising selected ones of the plurality of computing systems and their respective LAN databases with the registry database, wherein the LAN databases are synchronized by the secondary replica.

18. The synchronization system server of claim 17 wherein the primary replica comprises:

registry synchronization callouts for a specific LAN server to be synchronized.

19. The synchronization system of claim 17 wherein the LAN server comprises:

a LAN synchronization server, coupled to the primary replica;

a LAN server synchronization library, coupled to the LAN synchronization server, wherein registry modifications in the registry database affecting a local database or a group database within the DCE invokes the LAN server synchronization library to synchronize the affected database.

20. The synchronization system of claim 19 wherein the synchronization system server provides security and synchronization as a DCE cell for a plurality of distributed computing systems, each having a local registry database.

21. The synchronization system according to claim 19 further comprising means for determining whether the LAN synchronization library are present and active.

22. The synchronization system according to claim 19 wherein the LAN synchronization library serves as a filter and queue for updates for the LAN synchronization server.

23. The synchronizatin system according to claim 22 further comprising means for providing security within the DCE.

24. In a plurality of distributed computing systems, each having a local database, forming a distributed computing environment (DCE), a method for synchronizing the plurality of local databases comprising:

providing primary communication from one computing system to another computing system and with a registry database within the DCE;

establishing a secondary communications server for a local area network (LAN) of computing systems selected from the plurality of computing systems in the DCE;

establishing a LAN server synchronization library;

determining whether registry modifications in the registry database affect at least one of the plurality of local databases within the LAN;

invoking the LAN server synchronization library to synchronize the affected database.

25. The method according to claim 24 wherein the step of establishing the LAN server synchronization library further includes the step of determining whether the LAN synchronization library is present and active.

26. The method according to claim 24 wherein the LAN synchronization library performs the step of:

filtering and queueing updates for synchronization between the registry database and the local LAN databases.

27. The method according to claim 24 wherein the step of determing whether registry modifications are needed further includes the steps of:

receiving event notifications of an update to process; and

supervising update transmissions to the local databases from the registry database.

28. The method according to claim 24 also comprising the step of:

maintaining a list of LAN local databases that are allowed to register with the system server.

29. The method according to claim 24 the step of invoking step comprises:

retrieving all user and group information belonging to its associated LAN from each local database within the distributed computing environment;

synchronizing the LAN local databases in each registry within the DCE with the user and group information.

30. The method according to claim 29 wherein the LAN synchronizing step further comprises the step of:

invoking a callout to provide updates to the local registry databases within the DCE.

31. The method according to claim 24 wherein the step of providing primary communication comprises the step of:

generating shared memory objects for communicating with the secondary communications server.

32. The method according to claim 24 wherein the providing primary communication steps comprises:

establishing the primary communications as a primary replica;

placing a first registry object within a stub database with given a designated sequence number such that the sequence number of a next registry update is one greater than the previous update.

33. The method according to claim 24 wherein the establishing the secondary communications server step comprises:

establishing the secondary communications server as a secondary replica;

receiving the entire registry database of the DCE from a primary replica; and

establishing a propagation queue assigning a first propagation having a given sequence number wherein additional propagations are increased by one for each subsequent propagation for registry updates.

34. The method according to claim 24 wherein the LAN server synchronization library maintains a persistent copy of all valid LAN server updates received from the primary communication in an update log file.

35. The method according to claim 24 further comprising:

providing security within the DCE.

36. A method of synchronizing a distributed computing environment (DCE), comprising:

establishing a registry database coupled to each of a plurality of local DCE databases within each computing system within the DCE;

establishing a primary replica that synchronizes each of said plurality of local DCE databases within the DCE with the registry database, wherein each of said plurality of DCE databases is synchronized by the primary replica; and

establishing a secondary replica that synchronizes at least one local area network (LAN) server comprising selected ones of the plurality of computing systems and their respective LAN databases with the registry database, wherein the LAN databases are synchronized by the secondary replica.

37. The method of claim 36 wherein the step of establishing the primary replica comprises:

generating registry synchronization callouts for a specific LAN server to be synchronized.

38. A computer program product for use in a plurality of distributed computing systems, each having a local database, forming a distributed computing environment (DCE), the product for synchronizing the plurality of local databases comprising:

computer usable code means for providing primary communication from one computing system to another computing system and with a registry database within the DCE;

computer usable code means for establishing a secondary communications server for a local area network (LAN) of computing systems selected from the plurality of computing systems in the DCE;

computer usable code means for establishing a LAN server synchronization library;

computer usable code means for determining whether registry modifications in the registry database affect at least one of the plurality of local databases within the LAN;

computer usable code means for invoking the LAN server synchronization library to synchronize the affected database.

39. The computer program product according to claim 38 wherein the code means for establishing the LAN server synchronization library further includes computer usable code means for determining whether the LAN synchronization library is present and active.

40. The computer program product according to claim 38 wherein the LAN synchronization library includes:

computer usable code means for filtering and queueing updates for synchronization between the registry database and the local LAN databases.

41. The computer program product according to claim 38 wherein the code means for determing whether registry modifications are needed further includes:

computer usable code means for receiving event notifications of an update to process; and

computer usable code means for supervising update transmissions to the local databases from the registry database.

42. The computer program product according to claim 38 also comprising:

computer usable code means for maintaining a list of LAN local databases that are allowed to register with the system server.

43. The computer program product according to claim 38 wherein the code means for invoking comprises:

computer usable code means for retrieving all user and group information belonging to its associated LAN from each local database within the distributed computing environment;

computer usable code means for synchronizing the LAN local databases in each registry within the DCE with the user and group information.

44. The computer program product according to claim 43 wherein the LAN synchronizing code means comprises:

computer usable code means for invoking a callout to provide updates to the local registry databases within the DCE.

45. The computer program product according to claim 38 wherein the code means for providing primary communication comprises:

computer usable code means for generating shared memory objects for communicating with the secondary communications server.

46. The computer program product according to claim 38 wherein the providing primary communication code means comprises:

computer program product means for establishing the primary communications as a primary replica;

computer program product means for placing a first registry object within a stub database with given a designated sequence number such that the sequence number of a next registry update is one greater than the previous update.

47. The computer program product according to claim 38 wherein the establishing the secondary communications server code means comprises:

computer usable code means for establishing the secondary communications server as a secondary replica;

computer usable code means for receiving the entire registry database of the DCE from a primary replica; and

computer usable code means for establishing a propagation queue assigning a first propagation having a given sequence number wherein additional propagations are increased by one for each subsequent propagation for registry updates.

48. The computer program product according to claim 38 wherein the LAN server synchronization library maintains a persistent copy of all valid LAN server updates received from the primary communication in an update log file.

49. The computer program product according to claim 38 further comprising:

computer usable code means for providing security within the DCE.

50. A computer program product for synchronizing a distributed computing environment (DCE), comprising:

computer usable code means for establishing a registry database coupled to each of a plurality of local DCE databases within each computing system within the DCE;

computer usable code means for establishing a primary replica that synchronizes each of said plurality of local DCE databases within the DCE with the registry database, wherein each of said plurality of DCE databases is synchronized by the primary replica; and

computer usable code means for establishing a secondary replica that synchronizes at least one local area network (LAN) server comprising selected ones of the plurality of computing systems and their respective LAN databases with the registry database, wherein the LAN databases are synchronized by the secondary replica.

51. The computer program product of claim 50 wherein the code means for establishing the primary replica comprises:

computer usable code means for generating registry synchronization callouts for a specific LAN server to be synchronized.