SYSTEM AND METHOD FOR PROVIDING SESSION AFFINITY IN A CLUSTERED DATABASE ENVIRONMENT

• US 20130054516A1
• Filed: 02/16/2012
• Published: 02/28/2013
• Est. Priority Date: 06/27/2011
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Somogyi, Alexander, Revanuru, Naresh, Felts, Stephen, Zhou, Tong
• Granted Patent: US 8,635,185 B2
• Time in Patent Office: Days
• US Class Current: 707/609
• CPC Class Codes: G06F 16/23 Updating
• CPC Class Codes: G06F 16/256 in federated or virtual databases
• 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
• CPC Class Codes: G06F 16/28 Databases characterised by their database models, e.g. relational or object models
• CPC Class Codes: G06F 16/285 Clustering or classification

Abstract

A clustered database environment (e.g. Oracle Real Application Cluster (RAC)) includes multiple database instances that appear as one server. An application server (e.g. WebLogic Server (WLS)) can use a data source (e.g. an Oracle GridLink data source) and connection pools to connect with the clustered database. In accordance with an embodiment, a data source configuration allows for specification of a preferred affinity policy, such as a data affinity, temporal affinity, and/or session or session-based affinity policy. In accordance with an embodiment, the system includes a number of features that improve application connectivity in the clustered database environment, including a select-only case for application continuity, wherein an application-independent infrastructure, e.g. implemented within a Java Database Connectivity (JDBC) driver, enables recovery of work from an application perspective and masks system communications, hardware failures and hangs.

Claims

1. A system for supporting session affinity in a data source and clustered database environment, comprising:

a clustered database system, and a notification service associated with a plurality of database instances therein, wherein the notification service is used to broadcast notifications that describe state changes in the clustered database;

an application server, and a data source and connection pools associated therewith, wherein the data source and connection pools are used to manage connections to the plurality of database instances in the clustered database, and

wherein the data source can use session or session-based affinity, wherein database operations are directed to a particular database instance for a period of time when the application may be performing multiple, related updates to a specific data set.

2. The system of claim 1, wherein an affinity policy can be defined globally across multiple data sources, or individually for each data source, and wherein the affinity policy defines which type of affinity will be used by that data source at runtime.

3. The system of claim 2, wherein at runtime, when an application requests a connection from the data source which has a session affinity policy set, the system makes a callback to get any available web session contex, and if such a web session context is available, the system can use that to choose the most appropriate connection.

4. The system of claim 3, wherein the system can uses a functionality such as work context, which propagates around the system with the request, and wherein a servlet container can determine from the work context which is persisted with the web session, whether an affinity policy is set, and if so, set the work context as appropriate and retrieve additional information to then choose the most appropriate connection.

5. A method for supporting session affinity in a data source and clustered database environment, comprising the steps of:

providing access to a clustered database system, and a notification service associated with a plurality of database instances therein, wherein the notification service is used to broadcast notifications that describe state changes in the clustered database;

providing an application server, and a data source and connection pools associated therewith, wherein the data source and connection pools are used to manage connections to the plurality of database instances in the clustered database, and

wherein the data source can use session or session-based affinity, wherein database operations are directed to a particular database instance for a period of time when the application may be performing multiple, related updates to a specific data set.

6. The method of claim 5, wherein an affinity policy can be defined globally across multiple data sources, or individually for each data source, and wherein the affinity policy defines which type of affinity will be used by that data source at runtime.

7. The method of claim 6, wherein at runtime, when an application requests a connection from the data source which has a session affinity policy set, the system makes a callback to get any available web session contex, and if such a web session context is available, the system can use that to choose the most appropriate connection.

8. The method of claim 7, wherein the system can uses a functionality such as work context, which propagates around the system with the request, and wherein a servlet container can determine from the work context which is persisted with the web session, whether an affinity policy is set, and if so, set the work context as appropriate and retrieve additional information to then choose the most appropriate connection.

9. A non-transitory computer readable medium, including instructions stored thereon which when read and executed by one or more computers cause the one or more computers to perform the steps comprising:

providing access to a clustered database system, and a notification service associated with a plurality of database instances therein, wherein the notification service is used to broadcast notifications that describe state changes in the clustered database;

providing an application server, and a data source and connection pools associated therewith, wherein the data source and connection pools are used to manage connections to the plurality of database instances in the clustered database, and

wherein the data source can use session or session-based affinity, wherein database operations are directed to a particular database instance for a period of time when the application may be performing multiple, related updates to a specific data set.

10. The non-transitory computer readable medium of claim 9, wherein an affinity policy can be defined globally across multiple data sources, or individually for each data source, and wherein the affinity policy defines which type of affinity will be used by that data source at runtime.

11. The non-transitory computer readable medium of claim 10, wherein at runtime, when an application requests a connection from the data source which has a session affinity policy set, the system makes a callback to get any available web session contex, and if such a web session context is available, the system can use that to choose the most appropriate connection.

12. The non-transitory computer readable medium of claim 11, wherein the system can uses a functionality such as work context, which propagates around the system with the request, and wherein a servlet container can determine from the work context which is persisted with the web session, whether an affinity policy is set, and if so, set the work context as appropriate and retrieve additional information to then choose the most appropriate connection.