Assign a Minion to an appliance

A Minion associates a monitoring location with an appliance and optional Minion profile. When an appliance does not have a Minion, the Minion status area displays the Add Minion button.

A Minion profile lets you set Java virtual machine (JVM) parameters such as heap size, remote debug, and memory. You may want to create a Minion profile before you assign a Minion, but you can also create the profile later and update the Minion to add the profile to it.

To assign a Minion, follow these steps:

In the left menu, click Appliances.
Click the pencil icon beside the appliance to which you want to assign a Minion.
In the Minion section, click the Add (+) button.
Choose a monitoring location from the list.
(optional) To specify JVM attributes, choose a Minion profile from the list (see create Minion profile for JVM attributes).
Click Update.

After you assign a Minion, the appliance summary displays the Minion’s status in relation to OpenNMS:

Screen displaying Minion statuses including UP and UNKNOWN

The Minion can be in any of the following states:

UP: Online, running, and connected.
UNKNOWN: Online and running, but may not be connected.
GRACE_PERIOD: In a transient state.
DOWN: Not operational.

For more information about status classifications, see the global status mapping table.

Create Minion profile for JVM attributes

A Minion profile lets you set Java virtual machine (JVM) parameters such as heap size, remote debug, and memory. Create multiple Minion profiles to configure JVM attributes and reuse JVM configuration on a per-Minion basis.

Only users with an advanced understanding of JVM attributes should create Minion profiles.

In the left menu, click Appliances → Minion Profiles.
Click Configure JVM Flag.
Add JVM options separated by a comma (for example, -Xms1g, -Xmx2g to change the default heap size) and click Add New.

The Appliance Service dynamically creates the default heap size, based on 95% of the Minion container’s RAM size.
Navigate to the Minion Profiles screen and click Add New.
Type a name for the profile, choose a JVM configuration from the JVM Process Environment Config list, and click Add New.

To add a profile to an existing Minion, follow these steps:

In the left menu, click Appliances.
Click the pencil icon beside the appliance with the Minion that you want to update.
Expand the Minion section and choose the Minion profile from the Minion Profile list and click Update.

Changes to a Minion profile’s configuration respawns all Minions associated with that Minion profile. This process triggers a brief service interruption.

Verify Minion Appliance is visible in OpenNMS

When your Minion Appliance is up and running, you may want to check that it is visible in OpenNMS.

Sign in to your OpenNMS instance as an Admin user.
Under Info, choose Nodes.
Your Minion Appliance should appear in the list.

If the device does not appear in the list, see Why doesn’t this work? for troubleshooting help.

Verify Minion Appliance is UP/UP

A fully connected and properly operating Minion Appliance shows an "UP" Minion and OpenNMS status. You can view this in the list of appliances. See Global status mapping for details on different status indicators.