A user makes a request and is routed by a hardware load balancer to instance A of Instance A of the application becomes unavailable because of node failure, process The hardware load balancer marks instance A as unavailable. The user makes a subsequent re

Configuring High Availability for Oracle ADF and WebCenter Applications 6-43 – Routing traffic to all available instances – Configured correctly with a health monitor to mark unavailable instances – Configured to support persistence of session state

6.3.2.8 Expected Behavior for Application Failover

If the environment has been configured correctly, application users do not notice when an application instance in a cluster becomes unavailable. The sequence of events in an application failover is, for example, as follows:

1. A user makes a request and is routed by a hardware load balancer to instance A of

the application.

2. Instance A of the application becomes unavailable because of node failure, process

failure, or network failure.

3. The hardware load balancer marks instance A as unavailable.

4. The user makes a subsequent request. The request is routed to instance B.

5. Instance B is configured as a replication partner of Instance A and has the users

session state.

6. The application resumes using the session state on Instance B and the user

continues working without interruption. Exceptions to Expected Behavior For Oracle WebCenter, the known exceptions are as follows: ■ Oracle ADF Pop-ups - Open pop-ups close on failover, affecting the following components which otherwise have no exceptions: – Oracle Composer Property Inspector, EL Builder, Task Flow parameter picker, Resource String Editor – Save confirmation dialog box – Lists – Links link deletion pop-up When failover occurs, you must repeat the action that leads to the pop-up to make it reappear. The specific ways in which this appears in WebCenter Spaces and suggested remedies are listed in Table 6–7 . 6-44 Oracle Fusion Middleware High Availability Guide ■ Component Specific Issues - Other issues which are specific to different components in Oracle WebCenter are listed in Table 6–8 . Table 6–7 Oracle WebCenter Troubleshooting Scenarios Action Before Failover After Failover Suggested Remedy Go to any page and click Create Page . Type in a name, select a theme, and click OK. When you select the theme, the page creation pop-up closes. Repeat the operation. Launch Manage Pages. Perform any operation within the pop-up, except for closing the pop-up, for example, click Page Actions. When you perform any operation, the Manage Pages pop-up is closed. Repeat the operation. Launch Manage Pages, click Page Actions against a page, and then the Delete option in the menu. Click OK on the confirmation pop-up. Clicking OK closes the confirmation pop-up and the Manage Pages pop-up. The result of the deletion which may have gone through is not visible among the tabs. Relaunch the Manage Pages pop-up to see if the page is deleted. If not, try deleting once again. Launch Personalize Applications pop-up. Perform any operation that sends a request, other than clicking OK, for example, expand the Applications node. Perform any operation that sends a request, other than clicking OK, for example, expand the Applications node. When you perform any operation that sends a request to the server, the Personalize Applications pop-up is closed. Repeat the operation Launch Preferences. Switch between the Preferences tabs General, Accounts, Messaging, Search. When you switch between the Preference tabs, the Preferences pop-up is closed. Repeat the operation Launch Manage Favorites. Stop the server, perform any operation other than closing the pop-up. For example, expand a folder, click Edit favorite information . Perform any operation other than closing the pop-up, for example, expand a folder, and click Edit favorite information . When you perform any operation, the Manage Favorites pop-up is closed. Relaunch the Manage Favorites pop-up to see if the operation was successful. If not, retry the operation. Choose to edit applications and create a new folder An MDS exception opens. Retry the operation Work in Oracle Composer Customization Manager. Oracle Composer loses the state associated with the Customization Manager Relaunch Customization Manager. Select a component while in Oracle Composer Source View Oracle Composer loses track of the component. Repeat the operation Configuring High Availability for Oracle ADF and WebCenter Applications 6-45

6.3.2.9 Monitoring Logging of Application Deployments