Service monitors

To support several specific applications and management agents, Pollerd executes Service Monitors. This section describes all available built-in Service Monitors which are available and can be configured to allow complex monitoring. For information how these can be extended, see Development Guide of the OpenNMS documentation.

Common Configuration Parameters

Application or Device specific Monitors are based on a generic API which provide common configuration parameters. These minimal configuration parameters are available in all Monitors and describe the behavior for timeouts, retries, etc.

Table 1. Common implemented configuration parameters
Parameter Description Required Default value


Number of attempts to test a Service to be up or down.




Timeout for the isReachable method, in milliseconds.




Invert the up/down behavior of the monitor



In case the Monitor is using the SNMP Protocol the default configuration for timeout and retry are used from the SNMP Configuration (snmp-config.xml).

Minion Configuration Parameters

When nodes are configured with a non-default location, the associated Service Monitors are executed on a Minion configured with that same location. If there are many Minions at a given location, the Service Monitor may be executed on any of the Minions that are currently available. Users can choose to execute a Service Monitor on a specific Minion, by specifying the System ID of the Minion. This mechanism is used for monitoring the Minions individually.

The following parameters can be used to override this behavior and control where the Service Monitors are executed.

Table 2. Minion configuration parameters
Parameter Description Required Default value


Specify the location at which the Service Monitor should be executed.


(The location of the associated node)


Specify the System ID on which the Service Monitor should be executed




Use the foreign id of the associated node as the System ID



When specifying a System ID the location should also be set to the corresponding location for that system.

Using Placeholders in Parameters

Some monitor parameters support placeholder substitution. You can reference some node, interface, and asset record properties by enclosing them in { and }. The supported properties are:

  • nodeId

  • nodeLabel

  • foreignSource

  • foreignId

  • ipAddr (or ipAddress)

  • all node asset record fields (e.g. username, password)

Parameters that support placeholder substitution are marked 'Yes' in the 'Placeholder substitution' column of the Configuaration and Usage section of the monitor documentation.