MODELING DISTRIBUTION AND FAILOVER DATABASE CONNECTIVITY BEHAVIOR

• US 20110087636A1
• Filed: 10/08/2009
• Published: 04/14/2011
• Est. Priority Date: 10/08/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Olix, David W., Neerincx, Matt A., Mumford, Chadwin J., Michailov, Zlatko V.
• Granted Patent: US 8,996,909 B2
• Time in Patent Office: Days
• US Class Current: 707/655
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor

Abstract

Aspects of the subject matter described herein relate to database connectivity behavior. In aspects, an entity seeking to access data that is replicated via instances of a database follows a plan. The plan provides information as to which instance(s) the entity is to attempt to access the data from. The plan may include connection data that indicates parameters the entity is to use in connecting to the instance(s). The plan may also indicate one or more other instances from which the entity may attempt to access the data if the client is not able to access the data from initial instance(s).

Claims

1. A method implemented at least in part by a computer, the method comprising:

obtaining a plan regarding a database, the plan potentially including one or more of failover data and distribution data, the failover data, if any, indicating one or more instances of the database to which failover applies to access the replicated data, the distribution data, if any, indicating one or more instances of the database to which distribution applies to access the replicated data, the instances of the database providing access to the replicated data;

following the plan to determine at least one instance of the database from which to attempt to access the replicated data; and

if the at least one instance is unavailable for accessing the replicated data, determining whether the plan indicates at least another instance of the database from which to attempt to access the replicated data.

2. The method of claim 1, wherein obtaining a plan comprises obtaining a hierarchical data structure, the hierarchical data structure having one or more intermediate nodes and one or more leaf nodes, the intermediate nodes indicating the failover data, if any, and the distribution data, if any, the leaf nodes representing instances of the database, the leaf nodes indicating connection data associated with their represented instances of the database.

3. The method of claim 2, wherein following the plan comprises using the distribution data to determine one of the leaf nodes and subsequently using the connection data indicated by the one of the leaf nodes to attempt to access the replicated data on an instance of the database represented by the one of the leaf nodes.

4. The method of claim 2, wherein following the plan comprises using the failover data to determine at least one of the leaf nodes, subsequently using the connection data indicated by the at least one of the leaf nodes to attempt to access the replicated data on the at least one instance of the database, the at least one instance represented by the at least one of the leaf nodes, and if the at least one instance is unavailable for accessing the replicated data, using the failover data to determine at least another of the leaf nodes, the at least another of the leaf nodes representing the at least another instance.

5. The method of claim 1, wherein following the plan comprises using the distribution data to determine a server farm that includes the at least one instance of the database and subsequently using the failover data to determine the at least one instance from instances of the database hosted by servers of the server farm.

6. The method of claim 1, wherein following actions indicated by the plan comprises using the failover data to determine a server farm that includes the at least one instance of the database and subsequently using the distribution data to determine the at least one instance from instances of the database hosted by servers of the server farm.

7. The method of claim 6, wherein determining whether the plan indicates at least another instance of the database from which to access the replicated data comprises determining whether the failover data, if any, indicates that the at least another instance is a failover instance of the at least one instance.

8. The method of claim 1, wherein obtaining the plan comprises contacting a plan server external to an entity that follows the plan and requesting the plan from the plan server.

9. The method of claim 1, wherein obtaining the plan comprises retrieving data associated the plan from local volatile or nonvolatile memory.

10. The method of claim 1, wherein obtaining the plan comprises obtaining data associated with the plan from a user interface.

11. In a computing environment, an apparatus, comprising:

a plan manager operable to obtain a plan regarding a database that has replicated data, the plan potentially including one or more of failover data and distribution data, the failover data, if any, indicating one or more instances of the database to which failover applies to access the replicated data, the distribution data, if any, indicating one or more of the instances to which distribution applies to access the replicated data, the instances of the database providing access to the replicated data;

a plan evaluator operable to follow the plan to determine at least one instance of the database from which to access the replicated data; and

a connection manager operable to attempt to access the replicated data from the at least one instance of the database, the connection manager further operable to use connection data associated with the at least one instance of the database in conjunction with attempting to access the replicated data from the at least one instance of the database.

12. The apparatus of claim 11, wherein the plan indicates connection data for each instance that replicates the replicated data, the connection data for any instance of the database potentially being different from the connection data for another instance of the database.

13. The apparatus of claim 11, wherein the plan comprises a hierarchical data structure having one or more intermediate nodes and one or more leaf nodes, the intermediate nodes indicating the failover data, if any, and the distribution data, if any, the leaf nodes representing the instances of the database, the leaf nodes indicating connection data associated with their represented instances of the database.

14. The apparatus of claim 11, further comprising a distribution manager operable to determine, via the distribution data, an algorithm for distributing access requests among the one or more instances of the database, the distribution manager further operable to execute the algorithm to determine the at least one instance of the database from which to access the replicated data in response to a request from the plan evaluator.

15. The apparatus of claim 11, further comprising a failover manager operable to determine, via the failover data, whether a failover instance of the at least one instance is indicated, the failover manager further operable to instruct the connection manager to attempt to access the replicated data from the failover instance if the replicated data is not available from the at least one instance of the database.

16. The apparatus of claim 11, wherein the plan manager being operable to obtain a plan comprises the plan manager being operable to obtain the plan from one of:

a plan server external to the apparatus, volatile memory of the apparatus, non-volatile memory of the apparatus, and a user interface.

17. A computer storage medium having a hierarchical data structure encoded thereon, the hierarchical data structure encoding a plan, the hierarchical data structure comprising:

leaf nodes representing instances of a database that has replicated data that is accessible via functioning instances of the database;

one or more intermediate nodes that indicate failover data and/or distribution data, the failover data, if any, indicating one or more instances of a database to which a failover applies to access replicated data of a database, the distribution data, if any, indicating one or more of the instances to which distribution applies to access replicated data of the database; and

hierarchical data that indicates one or more relationships between the leaf nodes and/or the intermediate nodes.

18. The hierarchical data structure of claim 17, further comprising:

connection data that indicates connection parameters for connecting with the instances of the database, the connection parameters for one instance of the database potentially being different from the connection parameters for another instance of the database; and

association data that associates the connection data with the leaf nodes whereby each instance of the database is associated with at least some connection data.

19. The hierarchical data structure of claim 17, wherein the hierarchical data is indicated at least in part by an order in the hierarchical data structure of the leaf nodes and the intermediate nodes.

20. The hierarchical data structure of claim 17, wherein the distribution data indicates a distribution algorithm.