Auto Discovery

Auto discovery is the process of automatically adding nodes to Horizon. This is done through discovery, which is run either periodically on a schedule or as one-off, unscheduled operations.

Make sure you complete the tasks in Step 3: Provision Inventory before adding nodes.

Configure discovery

Configuring discovery specifies the parameters that Horizon uses when scanning for nodes. To configure discovery for a requisition, follow these steps:

  1. Log in to the Horizon web UI as a user with admin permissions.

  2. Click the gear symbol in the top-right of the page.

  3. Under Provisioning, click Configure Discovery.

    To configure a discovery scan to run only once, click Run Single Discovery Scan instead, and configure it as appropriate.

  4. (Optional) Under General Settings, define the scheduling options (sleep time, retries, timeout, and so on).

  5. Under Specific Addresses, click Add New to add an IP address for discovery:

    • Type the target IP address, the timeout, and the maximum number of retries in the appropriate boxes.

    • Choose a requisition from the Foreign Source list. Any discovered nodes will be added to this requisition upon discovery.

    • (Optional) If you have any installed Minions, choose one from the Location list.

    • Click Add to save the configuration settings.

  6. (Optional) Include specific URLs by clicking Add New under Include URLs:

    • Type the target URL, the timeout, and the maximum number of retries in the appropriate boxes.

    • Choose a requisition from the Foreign Source list.

    • (Optional) If you have any installed Minions, choose one from the Location list.

    • Click Add to save the configuration settings.

  7. (Optional) Exclude specific URLs by clicking Add New under Exclude URLs:

    • Type the target URL in the URL box.

    • Choose a requisition from the Foreign Source list.

    • (Optional) If you have any installed Minions, choose one from the Location list.

    • Click Add to save the configuration settings.

  8. (Optional) Set an inclusive range of IP addresses to add for discovery by clicking Add New under Include Ranges:

    • Type the beginning and ending IP addresses, the timeout, and the maximum number of retries in the appropriate boxes.

    • Choose a requisition from the Foreign Source list.

    • (Optional) If you have any installed Minions, choose one from the Location list.

    • Click Add to save the configuration settings.

  9. (Optional) Set an inclusive range to remove from discovery by clicking Add New under Exclude Ranges:

    • Type the beginning and ending IP addresses in the appropriate boxes.

    • (Optional) If you have any installed Minions, choose one from the Location list.

    • Click Add to save the configuration settings.

  10. Click Save and Restart Discovery.

After the discovery process is finished, navigate to the requisition that you specified to view the nodes that were found:

  1. Click the gear symbol in the top-right of the page.

  2. Under Provisioning, click Manage Provisioning Requisitions and find the requisition that you specified for the discovery process.

  3. (Optional) Click Edit beside the requisition’s name to manage its nodes.

    • Click Edit beside a node’s name to update its information.

    • Click Delete beside a node’s name to remove it from the requisition.

    • Click Synchronize to update the Horizon database with any changes.

Repeat the steps in this section for each requisition that you want to provision.

Automatic discovery detectors

Automatic discovery with detectors lets you specify the services to detect, as well as the ICMP ping, for specified IP addresses. Discovery sends a new suspect event only when the specified detectors succeed.

A definition that does not include specific detectors will fall back to ICMP ping for discovery.
Sample discovery configuration with detectors
<discovery-configuration xmlns="http://xmlns.opennms.org/xsd/config/discovery" packets-per-second="1"
    initial-sleep-time="30000" restart-sleep-time="86400000" retries="1" timeout="2000">

    <definition location="MINION" foreign-source="ApexOffice">

		<detectors>
			<detector name="reverse-dns-lookup" class-name="org.opennms.netmgt.provision.detector.rdns.ReverseDNSLookupDetector"/>
			<detector name="SNMP" class-name="org.opennms.netmgt.provision.detector.snmp.SnmpDetector">
				<parameter key="timeout" value="5000"/>
				<parameter key="ttl" value="120000"/>
			</detector>
		</detectors>

		<specific>10.0.0.5</specific>

		<include-range>
			<begin>192.168.0.1</begin>
			<end>192.168.0.254</end>
		</include-range>

    <exclude-range>
			<begin>192.168.0.120</begin>
			<end>192.168.0.125</end>
		</exclude-range>

		<include-url>file:/opt/opennms/etc/include.txt</include-url>

	</definition>

</discovery-configuration>

Configure manual discovery

In addition to the configuration settings above, there are some optional settings you can configure via ${OPENNMS_HOME}/etc/discovery-configuration.xml:

Name Description Default Value

packets-per-second

Number of ICMP packets that will be generated each second.

1

initial-sleep-time

Amount of time, in milliseconds, before the discovery process begins after Horizon has started. This delay allows Horizon to fully start before generating new events.

30000 (30 seconds)

restart-sleep-time

The time, in milliseconds, before the discovery process starts following its last run.

86400000 (1 day)

timeout

The amount of time, in milliseconds, that the discovery process will wait for a response from a given IP address before moving on.

2000

retries

The maximum number of attempts to query a given IP address before moving on.

1

foreign-source

Foreign source requisition to which discovered nodes will be added.

Blank

location

Monitoring location where the discovery batch will run. This is used only when at least one Minion has been deployed.

Default

chunk-size

Defines the number of IP addresses to delegate to each Minion for scanning, when using a monitoring location.

100
Discovery range configuration tags and examples
Tag Description

specific

Specify individual IP addresses to discover. May be repeated multiple times.

<specific>ip-address</specific>

include-range

Specify a range of IP addresses to discover. May be repeated multiple times.

<include-range>
    <begin>start-ip-address</begin>
    <end>end-ip-address</end>
</include-range>

exclude-range

Specify a range of IP addresses to exclude from discovery.

<exclude-range>
    <begin>start-ip-address</begin>
    <end>end-ip-address</end>
</exclude-range>
The exclude-range tag will override addresses only in an include-range. It will not override specific IP addresses or addresses included in a file. There is no "specific" version of the exclude tag. To exclude a specific IP address, use an exclude-range where the beginning and ending IP address is the same.

include-url

Specify the full path to a text file containing one IP address per line to include in discovery. You can embed comments in this file. Any content on a line after a # character is ignored.
You can use the following path formats:

<include-url>file:filename</include-url>
<include-url>http://IPADDRESS/filename</include-url>
<include-url>file:///path/to/file/on/local/server</include-url>