Administer the Cluster Agent

You can use several settings in the Controller to administer the Cluster Agent.

Plan the Cluster Agent Deployment

If you have more than one Cluster Agent on your Controller, you must start your Cluster Agents in a staggered fashion. This procedure ensures that the Controller responds optimally. Use the table to determine the stagger start time for each cluster. Based on the cluster size, it may take a few minutes for the Cluster Agent to fully register with the Controller.

Plan capacity for Clusters

Capacity planning is important when preparing to deploy the Cluster Agent. The Cluster Agent and the Machine Agent share the capacity of the same Controller. The total number of pods and containers in your cluster is equal to the number of Machine Agents slots that are used. For example, if you have 250 pods and 250 containers, that is equivalent to using 500 Machine Agents in the Controller. See Controller Sizing.

Controller Settings for the Cluster Agent

These properties are recommended for a Controller supporting the Cluster Agent. Certain Server Visibility properties will apply to all instances of Server Visibility and the Cluster Agent.

Property	Description	Recommended
`sim.cluster.agent.limit`	Maximum number of Cluster Agents per account. Configurable at the account level. For example, if you set the `sim.cluster.agent.limit` to a value of five, and you have ten Cluster Agents reporting, then the Controller randomly selects a subset of Cluster Agents. These random Cluster Agents will not be registered and reported. If the configured limit is reached, any new Cluster Agent will not be registered.	10
`sim.cluster.pod.limit`	Maximum number of pods per Cluster Agent per account. Configurable at the account level. If the number of pods exceeds the configured limit, the Cluster Agent randomly selects a set of pods that will not register or report.	1500
`sim.machines.registrations.maxPerSecondPerAccount`	Maximum number of machine registrations allowed per account, per second. This property applies to all instances of Server Visibility and the Cluster Agent.	10000
`sim.cluster.container.limit`	Controller level limit for the number of containers per cluster. This is used if there is no account-level configuration. To overwrite at account-level, add an additional property to the corresponding account. This property only affects the Cluster Agent.	3000
`sim.machines.offline.toStaleTimeoutMillis`	Length of time in milliseconds before an offline machine is considered stale, and eligible for purging. This property applies to all instances of Server Visibility and the Cluster Agent.	172,800,000 ms (2 days)
`sim.machines.registrations.update.frequency`	Machine's timestamp update frequency in milliseconds. This property applies to all instances of Server Visibility and the Cluster Agent.	86,400,000 ms (1 day)
`sim.cluster.events.maxPerMinute`	Controller level limit for the number of cluster events that are allowed per minute. This property only affects the Cluster Agent.	4000
`sim.machines.simAllowed`	Availability of Server Visibility features. This property must be set to true to send the data (metrics) from Cluster Agent to Controller.	true
`sim.cluster.monitoring.enabled`	This property enables the Cluster Agent on the Controller. If set to false, all Cluster Agents stop reporting metrics and components, but still register every minute. This property only affects the Cluster Agent.	true

See Controller Settings for Server Visibility.

To avoid the risk of purging live entities, ensure that the sim.machines.offline.toStaleTimeoutMillis value is always greater than the sim.machines.registrations.update.frequency value.

On-Premises Customers

For on-premises customers, to modify the Cluster Agent properties for your account:

Log in to the Administration Console with the administrator root password.
Select Controller Settings.
In the Controller Settings list, search for the setting.
In the Value field, enter the recommended value.
Click Save.
Log out of the Administrator Console.

SaaS Customers

For SaaS customers, create an AppDynamics Support ticket to have the Cluster Agent properties updated for your account.

Control Cluster Agent Reporting

You can stop and resume the Cluster Agent from reporting metrics and registering containers and pods. You can do this on a per-account basis, or on a Controller-wide basis.

Stop a Cluster Agent by Account

To stop the Cluster Agent on the Controller:

Log in to the Administration Console with the administrator root password.
Select Account Settings.
In the accounts list, double-click the account for which you want to configure the Cluster Agent.
In the Additional Properties pane, click +Add Property.
In the left field, enter "sim.cluster.monitoring.enabled".
In the right field, enter "false".
Click OK to save the property.
Log out of the Administrator Console.

Start a Cluster Agent by Account

To start the Cluster Agent on the Controller:

Log in to the Administration Console with the administrator root password.
Select Account Settings.
In the accounts list, double-click the account for which you want to configure the Cluster Agent.
Locate the sim.cluster.monitoring.enable property, and in the right field, enter "true".
Click OK to save the property.
Log out of the Administrator Console.
If the Cluster Agent has been stopped using the "sim.cluster.monitoring.enabled" setting, it does not resume reporting metrics and registering pods and containers until you enable the Cluster Agent using the User Interface. See Use the Cluster Agent.

Stop all Agents on the Controller

To stop all Cluster Agents on the Controller:

Log in to the Administration Console with the administrator root password.
Select Controller Settings.
In the Controller Settings list, search for the "sim.cluster.monitoring.enabled" setting.
In the right field, set the value to "false".
Click Save.
Log out of the Administrator Console.

Start all Agents on the Controller

To start all Cluster Agents on the Controller:

Log in to the Administration Console with the administrator root password.
Select Controller Settings.
In the Controller Settings list, search for the "sim.cluster.monitoring.enabled" setting.
In the right field, set the value to "true".
Click Save.
Log out of the Administrator Console.
If Cluster Agents have been stopped using the "sim.cluster.monitoring.enabled" setting, they do not resume reporting metrics and registering pods and containers until they are enabled through the User Interface. See Use the Cluster Agent.