Troubleshooting cache integration

Use this information to troubleshoot issues with your cache integration configuration, including HTTP session and dynamic cache configurations.

Procedure

Problem: HTTP session IDs are not being reused.
Cause: You can reuse session IDs. If you create a data grid for session persistence in Version 7.1.1 or later, session ID reuse is automatically enabled. However, if you created prior configurations, this setting might already be set with the wrong value.
Solution: Check the following settings to verify that you have HTTP session ID reuse enabled:
- The reuseSessionId property in the splicer.properties file must be set to true.
- The HttpSessionIdReuse custom property value must be set to true. This custom property might be set on one of the following paths in the WebSphere® Application Server administrative console:
  - Servers > server_name > Session management > Custom properties
  - Dynamic clusters > dynamic_cluster_name > Server template > Session management > Custom properties
  - Servers > Server Types > WebSphere application servers > server_name, and then, under Server Infrastructure, click Java and process management > Process definition > Java virtual machine > Custom properties
  - Servers > Server Types > WebSphere application servers > server_name > Web container settings > Web container
If you update any custom property values, reconfigure eXtreme Scale session management so the splicer.properties file becomes aware of the change.
Problem: When you are using a data grid to store HTTP sessions and the transaction load is high, a CWOBJ0006W message displays in the SystemOut.log file.
```
CWOBJ0006W: An exception occurred:
com.ibm.websphere.objectgrid.ObjectGridRuntimeException:
java.util.ConcurrentModificationException
```
This message occurs only when the replicationInterval parameter in the splicer.properties file is set to a value greater than zero and the Web application modifies a List object that was set as an attribute on the HTTPSession.

Solution: Clone the attribute that contains the modified List object and put the cloned attribute into the session object.
Problem: When running web applications with Servlet 3.0 spec, web application filters and listeners are not invoked by WebSphere eXtreme Scale session management. For example, listeners are not called back when sessions are invalidated using remote container eviction with WebSphere eXtreme Scale.
Cause: WebSphere eXtreme Scale does not identify filters and listeners defined using annotations or programmatically.

Solution: Filters and listeners must be explicitly declared in the web.xml file of the web application.