System providing methodology for replication subscription resolution

• US 7,346,633 B2
• Filed: 06/10/2004
• Issued: 03/18/2008
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: Sybase Incorporated (SAP SE)
• Original Assignee: Sybase Incorporated (SAP SE)
• Inventors: Li, Zhenpeng, Shang, Heping
• Primary Examiner(s): Gaffin; Jeffrey
• Assistant Examiner(s): PULLIAM, CHRISTYANN R
• Application Number:
  US10/709,974
• Publication Number:
  US 20050278346A1
• Time in Patent Office: 1,377 Days
• Field of Search: 707/201
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2255 Hash tables
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system providing methodology for replication subscription resolution. In one embodiment, for example, a system of the present invention for determining subscribers to which a published item of data should be replicated comprises: an interface module for receiving user input of lists of a plurality of subscribers, each list specifying items of data to be replicated to a given subscriber, a build module for building an index based on the lists of the plurality of subscribers containing entries indicating subscribers For each item of data specified in the lists and a default list of subscribers for items of data not matching any of the entries; and a resolution module for receiving a published item of data and determining subscribers to which the published item should be replicated based on the index.

Claims

1. A system which determines subscribers to which a published item of data is to be replicated, the system comprising:

a computer having a processor and memory;

an interface module which receives user input of lists from a plurality of subscribers, each list specifying items of data to be replicated to a given subscriber, wherein said lists include wildcard information and negation information;

a build module which builds an index based on the lists from the plurality of subscribers, the index including an entry for each item of data to be replicated and a bitmap string associated with each entry representing subscribers to each item of data, with at least one entry including a wildcard, and one entry including a default list of subscribers for items of data not matching any of the other entries, wherein the bitmap string includes one bit for each subscriber; and

a resolution module which receives a published item of data, determines subscribers to which the published item is to be replicated based on the index, and replicates enabling said published item to be replicated to subscribers, wherein time for determining subscribers to the published items does not depend on number of subscribers.

2. The system of claim 1, wherein at least one of the plurality of subscribers comprises a replicate database.

3. The system of claim 1, wherein the published item of data comprises an item of data published by a primary database for replication.

4. The system of claim 1, wherein the lists of from the plurality of subscribers include a list having negation information specifying at least one item of data not to be replicated to a particular subscriber.

5. The system of claim 1, wherein the lists from the plurality of subscribers include a list comprising a negation set indicating that all data other than items specified on the list should be replicated to a particular subscriber.

6. The system of claim 1, wherein the interface module receives at least one string identifying data to be replicated to a subscriber.

7. The system of claim 6, wherein the index comprises a hash table and the build module builds the hash table based, at least in part, on said at least one string.

8. The system of claim 1, wherein the index built by the build module comprises a hash table of entries based on the lists from the plurality of subscribers.

9. The system of claim 1, wherein the build module builds at least one entry including a wildcard providing that all items of data of a certain type are to be replicated to subscribers of said at least one entry.

10. The system of claim 1, wherein the build module builds a bitmap string representing the default list of subscribers.

11. The system of claim 10, wherein the build module adds each subscriber having a list comprising a whole set to the bitmap string representing the default list of subscribers.

12. The system of claim 10, wherein the build module adds each subscriber having a list comprising a negation set to the bitmap string representing the default list of subscribers.

13. The system of claim 1, wherein the resolution module generates a hashed value based on at least one string identifying the published item.

14. The system of claim 13, wherein the resolution module searches for the hashed value in the index.

15. The system of claim 14, wherein the resolution module determines subscribers to which the published item should be replicated based upon at least one entry in the index including the hashed value when the hashed value is found in the index.

16. The system of claim 14, wherein the resolution module determines subscribers to which the published item should be replicated based upon the default list when the hashed value is not found in the index.

17. The system of claim 13, wherein the resolution module receives a plurality of strings identifying the published item and substitutes a wildcard for one of the strings to search for matching entries in the index which include a wildcard.

18. The system of claim 1, wherein the resolution module determines subscribers to which the published item should be replicated based upon the default list of subscribers for published items without matching entries in the index.

19. The system of claim 1, wherein the build module removes a subscriber from the index in response to a request to remove a subscriber.

20. A method which determines subscribers to which a published item of data is to be replicated, the method comprising:

receiving lists from a plurality of subscribers, each list specifying items of data to be replicated to a given subscriber, wherein said lists include wildcard information and negation information;

building an index based on said lists from the plurality of subscribers, the index including any entry for each item of data to be replicated and a bitmap string associated with each entry identifying subscribers to which each item of data specified in said lists should be replicated, at least one entry including a wildcard, and one entry including a default list identifying subscribers to published items of data not matching any of the other index entries, wherein the bitmap string includes one bit for each subscriber;

given a published item of data, determining whether the published item matches at least one entry in the index, wherein time for determining subscribers to the published item does not depend on number of subscribers;

if the published item matches at least one entry in the index, generating a set of subscribers to which the published item is to be replicated based on the subscribers associated with said at least one entry; and

otherwise, returning the default list of subscribers to which the published item is to be replicated.

21. The method of claim 20, wherein at least one of the plurality of subscribers comprises a replicate database.

22. The method of claim 20, wherein the published item of data comprises an item of data published by a primary database for replication.

23. The method of claim 20, wherein said receiving step includes specifying items of data not to be replicated to a subscriber.

24. The method of claim 20, wherein said receiving step includes receiving a list comprising a negation set indicating that all data other than items specified on the list should be replicated to a subscriber.

25. The method of claim 20, wherein said receiving step includes receiving at least one string identifying data to be replicated to a subscriber.

26. The method of claim 25, wherein said index comprises a hash table and said building step includes building the hash table based on said at least one string.

27. The method of claim 26, wherein said step of building a hash table includes building a bitmap string for each entry representing subscribers to an item of data.

28. The method of claim 20, wherein said index comprises a hash table and said building step includes building a hash table of entries.

29. The method of claim 20, wherein said step of generating a bitmap string includes removing a subscriber from the bitmap string representing subscribers to an item of data when the subscriber has specified the item of data as an excluded item in a negation set.

30. The method of claim 20, wherein said building step includes building a bitmap string representing the default list of subscribers.

31. The method of claim 30, wherein said step of building a bitmap string for representing the default list of subscribers includes adding each subscriber having a list comprising a whole set.

32. The method of claim 30, wherein said step of building a bitmap string representing the default list of subscribers includes adding each subscriber having a list comprising a negation set.

33. The method of claim 20, wherein said building step includes building at least one entry including a wildcard indicating all items of data of a certain type should be replicated to a subscriber.

34. The method of claim 33, wherein said determining step includes receiving a plurality of strings identifying the published item and substituting a wildcard for one of the strings to search for matching entries in the index which include a wildcard.

35. The method of claim 20, wherein said determining step includes generating a hashed value based on at least one string identifying the published item.

36. The method of claim 35, wherein said determining step includes searching for the hashed value in the index.

37. The method of claim 20, wherein said determining step includes building a list of subscribers based upon a plurality of matching entries.

38. A computer-readable medium having processor-executable instructions which, when executed by a processor, perform the method of claim 20.