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This topic discusses techniques for finding and interpreting the information in the App Agent for Java log files.

Resolving App Agent for Java Startup Issues

After sending a request to your web application, data should appear in the UI. If no data appears, check the following:

1. You have re-started the application server.
2. Verify that the javaagent argument has been added to the startup script of your JVM.
3. Verify that you configured the agent-controller communication properties and agent identification properties in the controller-info.xml file or as system properties in the startup script of your JVM. See App Agent for Java Configuration Properties.
4. Check the Agent logs directory located at <Agent_Installation_Directory>/logs/<Node_Name> for the agent.log file.
5. Verify that the Agent is compatible with the Controller. For details see Agent - Controller Compatibility Matrix.

Locating the App Agent for Java Log Files

Agent log files are located in the <Agent_Installation_Directory>/logs/<Node_Name> folder.

The agent.log file is the recommended file to help you with troubleshooting. This log can indicate the following:

Error messages related to starting the App Agent for Java use this format:

ERROR com.singularity.JavaAgent - Could Not Start Java Agent

Resolving Incomplete Agent Configuration Issues

The following table lists the typical error messages for incomplete Agent configuration:

Error Message

Solution

Cannot connect to the Agent - ERROR com.singularity.XMLConfigManager -
Incomplete Agent Identity data, Invalid Controller Port Value []

This indicates that the value for the controller port in controller-info.xml is missing.
Add the port value, along with the host value (<your-host-name>), to fix this error.
(warning)

  • For on-premise Controller installations: Default port value is 8090 for HTTP and 8181 for HTTPS. 
  • For Controller SaaS service: Default port value is 80 for HTTP and 443 for HTTPS.

Caused by: com.singularity.ee.agent.configuration.a:
Could not resolve agent-controller basic configuration

This is usually caused because of incorrect configuration in the Controller-info.xml file.
Ensure that the information for agent communication (Controller host and port) and agent identification (application, tier and node names) is correctly configured.
Alternatively, you can also use the system properties (-D options) or environment variables to configure these settings.

For more information about agent properties see App Agent for Java Configuration Properties.

Unblocking the Controller Port

The following table lists the typical error message when the Controller port is blocked in your network:

Error Message

Solution

ERROR com.singularity.CONFIG.ConfigurationChannel - Fatal transport error: Connection refused
WARN com.singularity.CONFIG.ConfigurationChannel - Could not connect to the controller/invalid response from controller,
cannot get initialization information, controller host \x.x.x.x\, port 8090, exception Fatal transport error: Connection refused

Try to ping <your-host-name> from the machine where you have configured the Application Server Agent.
If it works, then confirm if the Controller port is not blocked in your network.
(info) To check if a port was blocked in the network; use command: netstat -an for Windows and nmap for Linux.
 
(warning) * For on-premise Controller installations: Default port value is 8090 for HTTP and 8181 for HTTPS.

  • For Controller SaaS service: Default port value is 80 for HTTP and 443 for HTTPS.

Correcting File Permission Issues

Following table lists the typical error message when the file permissions are not correct:

Error Message

Solution

ERROR com.singularity.JavaAgent - Could Not Start Java Agent com.singularity.ee.agent.appagent.kernel.spi.c: Could not start services"

This is usually caused because of incorrect permissions for log files.
Confirm if the user who is running the server, has read and write permission on the agent directories.
If the user has chmod a-r equivalent permission, change the permission to chmod a+r "<agent_directory>"

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