The Java Agent identifies and tracks business transactions, captures statistics and diagnostic data, and analyzes and reports data to the Controller. The Java Agent uses dynamic bytecode injection to instrument a JVM and it runs as a part of the JVM process.

Caution: The Java Agent may fail if there are other Application Performance Management (APM) products installed in the same JVM.  They can coexist as long as the other APM does not interfere with the Java Agent class transformations. We discourage the simultaneous use of other Byte Code Injection (BCI) agents.

Overview of the Java Agent Installation Process

Installing the Java Agent involves adding it as a javaagent (Java Programming Language Agent) on your JVM and setting up connection and identifying parameters for it to report data to the Controller.

Install the Java Agent as the same user or administrator of the JVM. Otherwise the Java Agent may not have the correct write permissions for the system. The Java Agent directories must have write permission so that AppDynamics can update the logs and other Java Agent files.

Planning for Java Agent Installation

Before installing the Java Agent, be prepared with the following information.

Important Files

In addition to the JVM startup script file, two other files are important during installation:

• The -javaagent argument uses the fully-qualified path of the javaagent.jar file. No separate classpath arguments need to be added.

• The <agent_home>/conf/controller-info.xml file is where you add the configuration mentioned in the planning list.

To Install the Java Agent

1. Download and unzip the Java Agent

• Download the Java Agent ZIP file from AppDynamics Download Center.
• Extract the ZIP file to the destination directory as the same user or administrator of the JVM. Take note of the following:
  • Extract the Java Agent to a directory that is outside of your container
  • All files should be readable by the Java Agent
  • Runtime directory should be writable by the Java Agent

Note: Do not unzip/install the Java Agent into to the ..\tomcat\webapps directory. By default Tomcat tries to undeploy and deploy files under the webapps folder. To avoid the possibility that Tomcat will occasionally not restart, we recommend installing the Java Agent to a directory outside of tomcat, such as \usr\local\agentsetup\AppServerAgent.

2. Add the Java Agent properties as a 'javaagent' argument to your JVM

This step adds the Java Agent to the startup script of your application server. Use the server-specific instructions below to add this argument for different application server JVMs:

3. Configure how the Java Agent connects to the Controller

• Configure properties for the Controller host name and its port number.
• You can configure these two properties using either the controller-info.xml file or the JVM startup script:

Optional settings for Java Agent-to-Controller communication

• To configure the Java Agent to use SSL, see App Agent for Java Configuration Properties
  and Enable SSL (Java).
• To configure the Java Agent to use proxy settings see App Agent for Java Configuration Properties

4. (Only for Multi-tenant mode or SaaS Installations) Configure Java Agent account information

• This step is required only when the AppDynamics Controller is configured in Controller Tenant Mode or when you Use a SaaS Controller.
  Skip this step if you are using single-tenant mode, which is the default in an on-premise installation.

• Specify the properties for Account Name and Account Key. This information is provided in the Welcome email from the AppDynamics Support Team. You can also find this information in the <controller-install>/initial_account_access_info.txt file.

5. Configure how the Java Agent identifies the AppDynamics business application, tier, and node

When configuring an Java Agent, you identify the business application, tier, and node it belongs to in the AppDynamics application model. See
Logical Model and Name Business Applications, Tiers, and Nodes for more information on this model.

You can configure these properties using either the controller-info.xml file or JVM startup script options. Use these guidelines when configuring agents:

• Configure items that are common for all the nodes in the controller-info.xml file.
• Configure information that is unique to a node in the startup script.

-javaagent:<agent_home>/javaagent.jar=uniqueID=<my-app-jvm1>

Additional Installation Scenarios

Refer to the links below for typical installation scenarios, especially for cases where there are multiple JVMs on the same machine:

• Configure App Agent for Java on Multiple JVMs on the Same Machine that Serves the Same Tier
• Configure App Agent for Java on Multiple JVMs on the Same Machine that Serve Different Tiers
• Configure App Agent for Java to Use Existing System Properties
• App Agent for Java on z-OS or Mainframe Environments Configuration
• Configure App Agent for Java for Batch Processes
• Add the Agent into an Embedded JVM

6. Verify Java Agent configuration

• Ensure that you have added -javaagent argument in your JVM startup script. This is not a -D system property but a different standard argument for all JVMs v1.5 and higher.
• Ensure that you have added all mandatory items either in the Java Agent controller-info.xml file or in the JVM startup script file.
• The user running the JVM process/application server process is the user accessing the Java Agent installation.

7. Verify successful installation and reporting

a. Verify Java Agent installation

After a successful install, your Java Agent logs, located at <agent_home>/logs, should contain following message:

Started AppDynamics Java Agent Successfully

If the agent log file is not present, the Java Agent may not be accessing the javaagent command properties. The application server log file where STDOUT is logged will have the fallback log messages, for further troubleshooting.

b. Verify that the Java Agent is reporting to the Controller

Use the AppDynamics UI, to verify that the Java Agent is able to connect to the Controller:

• Point your browser to: http://<controller-host>:<controller-port>/controller
• Provide the admin credentials to log into the AppDynamics UI.
• Select the application. In the left navigation pane, click Servers -> App Servers -> <tier> -> <node>. Click the Agents tab and App Server Agent subtab. An agent successfully reporting to the Controller will be listed and the Reporting property shows an "up" arrow symbol. For more details see Verify App Agent-Controller Communication.
• When deploying multiple agents for the same tier, see if you get the exact number of nodes reporting in the same tier.

Example Configuration: Java Agent Deployment on a Single JVM

The following example shows a sample deployment of the Java Agent for the ACME Bookstore.

• Add the javaagent argument to the start-up script of the JVM:

java -javaagent:<install_dir_for_agent>/javaagent.jar

• Define the five mandatory items for agent configuration in the  Java Agent controller-info.xml file:

<controller-info>
    <controller-host>192.168.1.20</controller-host>
    <controller-port>8090</controller-port>
    <application-name>ACMEOnline</application-name>
    <tier-name>InventoryTier</tier-name>
    <node-name>Inventory1</node-name>
</controller-info>

Learn More

• App Agent for Java Configuration Properties
• Uninstall the Java Agent
• Logical Model