Synchronization of computer databases using caching agents

• US 7,814,053 B1
• Filed: 09/11/2002
• Issued: 10/12/2010
• Est. Priority Date: 05/02/2002
• Status: Expired due to Fees

• Current Assignee: Access Company Limited
• Original Assignee: ACCESS Systems Americas Incorporated (Access Company Limited)
• Inventors: Pivowar, Alvin I., Poddar, Jayita
• Primary Examiner(s): Truong; Cam Y T
• Application Number:
  US10/242,344
• Time in Patent Office: 2,953 Days
• Field of Search: 707200-205, 707/8, 707/3, 711/161
• US Class Current: 707/614
• CPC Class Codes: G06F 16/24552 Database cache management
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• 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 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A method and system for synchronization of computer databases using caching agents. In one embodiment, information is accessed from a first database. The information is stored into a persistent store, which may be a permanent media, such as a magnetic disk. The information is retrieved from the persistent store. Such retrieval may be in close time proximity to the storing, or the retrieval may be at a substantially different time from the storing. The synchronization is completed by updating a second database with the information retrieved by the caching agent from the persistent store. As an advantageous result, synchronization of computer databases is more efficient due to an optimized storage format for the information as well as maximum bandwidth access. As a further beneficial result, if a database is not present at the time of synchronization, embodiments of the present invention may enable synchronization capabilities unavailable under the prior art.

Claims

1. A computer implemented method of synchronizing database information using a caching agent software module associated with a persistent store, the method comprising the steps of:

accessing, by a processor, coverage information as part of a first synchronization process between a first database and a second database for determining new data items to said caching agent software module by monitoring communication during the first synchronization process, wherein said coverage information is a tuple of versioning of said first and second databases;

storing said data items into said persistent store during said first synchronization process and updating said coverage information of said caching agent software module associated with said first synchronization process and the stored data items, wherein said updating is based on a synchronization clock, said coverage information describes a level of information in at least one database of said first and second databases;

adding a present value of said synchronization clock to a description of the coverage information of said first database in response to a change to a data element of said first database;

determining delta information needed by the at least one database to bring coverage to maximum level and updating said at least one database to maximum coverage level; and

without said first and second databases participating in a second synchronization, synchronizing a third database using in part said stored coverage information residing in the persistent store from said first synchronization process to identify the new data items to synchronize with said third database, and allowing for said third database to be updated with said data items from the databases that are not currently participating in said second synchronization, but are stored in said persistent store.

2. The method of synchronizing database information as described in claim 1 wherein said first synchronization process takes place at substantially the same time as said accessing.

3. The method of synchronizing database information as described in claim 1, wherein said first database is not available to said second database at the time of retrieving.

4. The method of synchronizing database information as described in claim 1 wherein said first database and said second database are not accessible at the same time for each other.

5. The method of synchronizing database information as described in claim 1 wherein said caching agent software module is single ended.

6. The method of synchronizing database information as described in claim 1 wherein said persistent store is accessed only by said caching agent software module.

7. The method of synchronizing database information as described in claim 1, further comprising making said information in the persistent store available to other databases for synchronizing.

8. The method of synchronizing database information as described in claim 1, wherein said storing further comprises synchronizing said information from the first database with previously-stored information in the persistent store.

9. The method of synchronizing database information as described in claim 1 wherein said second synchronizing takes place at a substantially different time from said accessing.

10. A removable storage media connected to a computing device storing instructions for controlling said computing device, the instructions associated with a single ended synchronization agent software module that caches database information for synchronizing a first database and a second database, the instructions comprising:

accessing coverage information associated with a first synchronization process between the first database and the second database to determine new data items to the single ended synchronization agent software module during said first synchronization process, wherein said coverage information is a tuple of versioning of said first and second databases,

storing said data items in a persistent store during said first synchronization process and updating said coverage information to represent addition of the data items, wherein said updating is based on a synchronization clock and said coverage information describes a level of information in at least on database of the first and second databases;

adding a present value of said synchronization clock to a description of the coverage information of said first database in response to a change to a data element of said first database;

determining delta information needed by the at least one database to bring coverage to maximum level and updating said at least one database to maximum coverage level; and

without said first and second databases participating in a second synchronization, synchronizing a third database using in part said stored coverage information residing in the persistent store from said first synchronization process to identify the data items to synchronize with said third database, and allowing for said third database to be updated with said data items from the databases that are not currently participating in said second synchronization, but are stored in said persistent store.

11. The removable storage media of claim 10 wherein said retrieving takes place while said first database is accessible by a synchronization system and wherein said first database is a source of at least a portion of said database information.

12. The removable storage media of claim 10 wherein retrieving takes place while said first database is not accessible by a synchronization system and wherein said first database is a source of at least a portion of database information.

13. The removable storage media of claim 10 wherein database information originates from said first and second databases and at least one other database.

14. The removable storage media of claim 10 wherein said persistent store is associated with a caching agent software module.

15. A system for synchronizing database information comprising:

a memory; and

at least one processing device configured to;

access coverage information associated with a first synchronization process between a first database and a second database, wherein said coverage information is a tuple of the versioning of said first and second databases and describes a level of information in at least one database;

store new data items based on said coverage information into a persistent store during said first synchronization process and updating said coverage information based on a synchronization clock;

adding a present value of said synchronization clock to a description of the coverage information of said first database in response to a change to a data element of said first database;

determining delta information needed by the at least one database to bring coverage to maximum level and updating said at least one database to maximum coverage level; and

without said first and second databases participating in a second synchronization, synchronizing a third database using in part said stored coverage information residing in the persistent store from said first synchronization process to identify the data items to synchronize with said third database, and allowing for said third database to be updated with said data items from the databases that are not currently participating in said second synchronization, but are stored in said persistent store.

16. The system as described in claim 15 wherein said first database is not accessible at the time of retrieving.

17. The system as described in claim 16 wherein the database information is associated with a plurality of databases residing on a hand held computer.

18. The system as described in claim 16 wherein said synchronizing takes place at substantially the same time as said accessing.

19. The system as described in claim 16 wherein said first database and said second database are not accessible at the same time.

20. The system as described in claim 15 wherein said storing is controlled by a single ended caching agent software module.

21. The system as described in claim 20 wherein said retrieving is controlled by said single ended caching agent software module.

22. The system as described in claim 20 wherein said persistent store is not accessed by application programs.

23. The system as described in claim 15 wherein said second synchronizing takes place at a substantially different time from said accessing.

24. The system as described in claim 15 wherein said processing device is further configured to synchronize said information from the first database with previously-stored information in the persistent store.

25. The system as described in claim 15 further comprising a module configured to make the information in the persistent store available to other databases for synchronizing.