ADDING INDIVIDUAL DATABASE FAILOVER/SWITCHOVER TO AN EXISTING STORAGE COMPONENT WITH LIMITED IMPACT

• US 20090327519A1
• Filed: 06/26/2008
• Published: 12/31/2009
• Est. Priority Date: 06/26/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bansal, Yogesh, Wistrom, Mark, Kleewein, James, Kuppusamy, Manoharan, Benfield, Rebecca, Thiel, Gregory, Wetmore, Alexander R., Kol, Ayla, Sundaram, Naresh
• Granted Patent: US 8,275,907 B2
• Time in Patent Office: Days
• US Class Current: 709/239
• CPC Class Codes: G06F 11/2025 using centralised failover control functionality
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• CPC Class Codes: G06F 11/2041 with more than one idle spare processing component
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06Q 10/107 Computer-aided management of electronic mailing [e-mailing]
• CPC Class Codes: H04L 51/56 Unified messaging, e.g. interactions between e-mail, instant messaging or converged IP messaging [CPM]
• CPC Class Codes: H04L 67/025 for remote control or remote monitoring of applications
• 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 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

High availability architecture that employs a mid-tier proxy server to route client communications to active data store instances in response to failover and switchover. The proxy server includes an active manager client that interfaces to an active manager in each of the backend servers. State information and configuration information are maintained separately and according to semantics consistent with needs of corresponding data, the configuration information changing less frequently and more available, the state information changing more frequently and less available. The active manager indicates to the proxy server which of the data storage instances is the currently the active instance. In the event that the currently active instance is inactive, the proxy server selects a different backend server that currently hosts the active data store instance. Client communications are then routed to the different backend server with minimal or no interruption to the client.

Claims

1. A computer-implemented data system, comprising:

a proxy component for routing communications between clients and backend servers; and

configuration information for representing the proxy component as a data storage component, the representation facilitating high availability of data in response to failover at the backend servers.

2. The system of claim 1, further comprising state information that includes status of the backend servers and associated backend data store instances, and location of an active backend data store instance.

3. The system of claim 2, wherein the state information is stored and maintained separately from the configuration information.

4. The system of claim 1, further comprising an active manager client as part of the proxy component that communicates to an active manager of a backend server to locate an active data store instance as part of failover and switchover.

5. The system of claim 1, wherein the proxy component discards session information of a communications session between a client and a backend server when the session ends.

6. The system of claim 1, wherein the backend servers and associated backend data store instances are made peer objects.

7. The system of claim 1, wherein the backend servers are messaging storage servers having associated message data store instances, and the proxy component connects the clients to an active message data store instance from an inactive message data store instance during failover.

8. The system of claim 1, further comprising a referral component for processing a referral from a backend mailbox server to which a client attempts to interact, or a referral from the proxy component to the backend mailbox server, the referral indicates a different backend mailbox server that hosts an active mail data store instance.

9. A computer-implemented data system, comprising:

a proxy component for routing communications between messaging clients and messaging storage servers;

configuration information for representing the proxy component as a data storage component; and

an active manager client as part of the proxy component that communicates with the messaging storage servers to locate an active message data store instance in response to failover.

10. The system of claim 9, further comprising state information that includes status of the messaging storage servers and associated message data store instances, and location of the active message data store instance, the state information stored and maintained separately from the configuration information.

11. The system of claim 10, wherein the state information and the configuration information are maintained separately according to semantics consistent with needs of corresponding data, the configuration information changing less frequently and more available, the state information changing more frequently and less available.

12. The system of claim 9, wherein the active manager client facilitates activation of a new message data store instance and begins directing the clients associated with a hub transport component, a mid-tier client access component, unified messaging component to the new active message data store instance.

13. The system of claim 9, wherein the messaging storage servers each include an active manager that communicates with the active manager client, the active manager client uses the configuration information to find the messaging storage servers and to direct queries to the associated active managers for the active message data store instance.

14. A computer-implemented data method, comprising:

receiving client communications of a client at a mid-tier proxy server;

accessing configuration information that defines backend servers of a server cluster for selection and for directing queries;

querying the selected backend servers for a currently active data store instance; and

routing the client communications via the proxy server to an active backend server hosting the currently active data store instance.

15. The method of claim 14, further comprising:

detecting that the currently active data store is inactive; and

routing the client communications to a newly selected active data store instance.

16. The method of claim 14, further comprising:

processing state information that maintains active/inactive state of data store instances and associated backend servers; and

routing the client communications to the newly selected active data store instance based in part on the state information.

17. The method of claim 16, further comprising maintaining the state information separately from the configuration information, the state information and the configuration are maintained according to semantics consistent with needs of corresponding data, the configuration information changing less frequently but more available than the state information, which changes more frequently relative to the configuration information.

18. The method of claim 14, further comprising receiving a referral from a selected backend server to route the client communications to a different backend server, and routing the client communications to the different backend server.

19. The method of claim 14, wherein the proxy server includes one of a hub transport role, a unified communications server role, or a client access server role.

20. The method of claim 14, further comprising representing the proxy server as a data storage component in the configuration information to provide high availability failover and switchover of data stores instances associated with the backend servers.