From the AppDynamics Agents page, you can manage, reset, and disable app agents connected to the Controller, and view agent status and information.  

Permissions

To manage app agents, you must belong to a role with the Account level permission:

  • Administer users, groups, roles, authentication, and so on 
  • View license
  • View AppDynamics agents
  • Use Agent Download Wizard

The predefined Account Owner role includes the required permission. 

To access app agent administration settings, click Settings > AppDynamics Agents > App Server Agents. 

Associate App Agents with a Business Application

If you start an application server with an app agent without specifying the business application, the agent appears in the App Server Agents tab as an unassociated agent. You can associate an agent with an application manually:

  1. From the agents list in the App Server Agents tab, select the unassociated app agent from the list.

    In the View menu, click Agents not associated with an Application to filter the list of App Server Agents.

  2. Click Associate with Application. This button is enabled only for app agents that are connected to the Controller but not associated with a business application. 

Reset App Agents

To reset app agents, users need the "Agent Advanced Operation" permission.
Resetting the app agent causes the agent to register itself with the Controller in the same way it does at JVM or application startup, but without restarting the JVM or application. Resetting the app agent purges in-memory data for the agent. It also applies certain configuration changes to the app agent, such as app agent node property changes. 

Resetting an app agent causes the Controller to:

  • Purge data such as in-memory business transactions and metrics, exit calls, and registration information for the agent  
  • Reset the business transaction limit counter to zero for the selected agent

Resetting an agent does not re-instrument or remove existing instrumentation. After a reset, the agent re-registers business transactions and backends and it creates new metrics. You may lose a few minutes worth of data between the reset and re-registration operations.

You may need to reset agents after you have reconfigured business transaction or backend detection and the agent is not applying the updated rules:

  1. Delete all existing transactions and backends. See information on deleting unwanted business transactions in Transaction Detection Rules, Monitor Databases, and Remote Services.
  2. Choose a reset option:
    • To reset all the app agents for a business application, click Reset Agents.
    • To disable a individual app agents, select one or more agents and click Reset Selected App Agent(s).

Enable and Disable App Agents

Disabling an app agent stops the agent from reporting metrics to the Controller. Disabling an agent can help you diagnose agent installation or application issues. It also lets you compare the difference in overhead between when the agent when capturing data versus when it is not, for example, without removing the agent. Disabling the agent does not require you to shut down or restart the application server.

Disabling an app agent does not stop the agent from operating or remove the bytecode instrumentation added by the agent. To fully remove the agent including remove bytecode instrumentation, follow the steps to uninstall the app agent or fully disable agent instrumentation under the Install App Server Agents page specific for the agent type. Uninstalling an app agent or fully disabling an app agent in this manner typically requires an application restart. 

All agents connected to the Controller count against the agent license limits for that Controller. Even though it only reports minimal app server-related data, a disabled app agent is still connected to the Controller and consumes an app agent license. 

To enable or disable all the app agents for a business application, the App Server Agents tab, click Enable Agents or Disable Agents.

Permission:

You must have the application-level permission, configure agent properties to enable and disable agents.

You can enable or re-enable individual agents by selecting them and clicking Enable Selected App Agent or Disable Selected App Agent. Alternatively, enable or disable app agents individually from the Agents tab on the Node Dashboard:

  • To disable the agent, click Agent is Off.
  • To enable the agent, click Agent is On.
    It takes about a minute for the operation to take effect.

By default turning the agent Off completely disables monitoring. For Java agents, un-check Disable all monitoring including JVM and JMX metrics on the Disable This App Agent pane to continue collecting JVM and JMX metrics such as heap memory, memory pools, garbage collection, and thread count.

Delete App Agents

Deleting an app agent removes the agent and any associated data from the Controller database. This does not affect the instrumentation of the application server. If the application server is still running with an app agent, or if it is subsequently restarted with an app agent, the agent re-registers and appears again in the Controller.

You can delete an app agent by clicking Delete Agent from System.

To completely remove an app agent completely so that it does not register again, uninstall it. See uninstallation instructions for your agent platform under Install App Server Agents.