When an error occurs in a J2EE server or Web server, after following the procedure shown in 2.2.1 Overview of Troubleshooting, take appropriate actions and start the J2EE server or Web server. For details on how to restart J2EE servers or Web servers, see 4.1.24 Starting the system (when using CUI) in the uCosminexus Application Server System Setup and Operation Guide.

Note that if you stop a J2EE server due to an error, restart the Web server that sends a request to the J2EE server where the error occurred. If you do not restart, the redirector continues to use the established connection that is already invalid. As a result, the Web server keeps waiting till a communication timeout occurs after forwarding the request to the J2EE server where the error occurred, and after the communication time out the request is sent back to the client as an error.

For details on the communication timeout, see 4.6 Communication timeout (Web Server integration) in the uCosminexus Application Server Web Container Functionality Guide or 5.9 Communication timeout (In-process HTTP server) in the uCosminexus Application Server Web Container Functionality Guide.

If an error occurs in an SFO server, after clearing the cause of the error by acquiring the necessary data in the same way as in a J2EE server, restart the SFO server.

Further, when you restart the SFO server, the J2EE server reconnects to the SFO server. At this time, the negotiations process same as that at the time of initialization takes place between J2EE server and SFO server.

In the negotiation process, confirm whether the following information is shared between J2EE applications on redundant J2EE servers:

• Context root name of the Web application
• Upper limit for the number of HttpSessions
• Maximum size of the session information
• HTTP Cookie name used by the global session ID
• Timeout till lock wait within the SFO server

When this information between J2EE applications on the redundant J2EE servers differs, for those web applications, the memory session failover function continues to be invalid, but the SFO server is not reconnected.

In this case, stop the corresponding J2EE application once and restart it after you make the settings for the J2EE application memory session failover correctly.

When using the memory session failover function, a log is output by the J2EE server and SFO server that uses the memory session failover function. Check this log if required when an error occurs.

The following table describes the correspondence between the log output level and the contents output in a J2EE server.

Table 2-13 Correspondencebetween the log output level and the contents output in a J2EE server

Log output level	Contents that are output
Error	Information about starting and stopping of memory session failover function Information about the connection with the SFO server Information about error occurrence in the SFO server Information reporting that the size estimation functionality of the global session information is valid. Size information by the size estimation functionality of the global session information.
Warning	Information on the inheritance of the global session information Reporting that global session ID was not found by the invalid global session (expired) request
Information	Check results of the health check thread

The following table describes the correspondence between the log output level and the output contents in the SFO server.

Table 2-14 Correspondencebetween the log output level and the output contents in the SFO server

Log output level	Contents that are output
Error	Information related to starting and stopping of the SFO server Information related to errors that occurred in the SFO server Reporting that the number of global sessions for the maximum value is "0%","20%","40%","60%","80%", or "100%" Number of global sessions destroyed due to the expired validity in the SFO server
Warning	Global session ID of the global session destroyed due to the expired validity in the SFO server Reporting of a creation request for a global session as the maximum value of the number of global sessions has exceeded Notification of a request to acquire invalid global sessions (expired validity)
Information	Detailed information of global sessions destroyed due to expired validity in the SFO server