Step 2: Turn on Default Notifications

This section describes how to turn on default notifications in Horizon.

Horizon uses notifications to inform users about events in the network without requiring them to log in to the web UI. Notifications are commonly sent through email and text/pager messages, but can be customized to send to a variety of external systems. For additional information, including alternative notification mechanisms, see Notifications in the Deep Dive section and the notifd daemon reference section.

Enable notifications

Notifications are disabled by default in a fresh Horizon installation, as indicated by the red bell symbol in the menu bar:

red bell notifications

Follow these steps to enable notifications:

  1. Log out of the admin account and log in as the user you created in Step 1: First-Time Login.

  2. Click the Gear symbol in the top-right of the screen.

  3. Under Event Management, click On beside Notification Status, and click Update. The red bell symbol in the top menu bar turns green, indicating that notifications are enabled globally.

notifications-on
The workflow above is functionally equivalent to editing ${OPENNMS_HOME}/etc/notifd-configuration.xml and setting status="on" in the top-level notifd-configuration element. This configuration file update happens immediately, with no need to restart Horizon.

The following event notifications are defined by default:

  • High threshold (off by default)

  • High threshold rearmed (off by default)

  • Low threshold (off by default)

  • Low threshold rearmed (off by default)

  • interfaceDeleted (on by default)

  • interfaceDown (on by default)

  • nodeAdded (on by default)

  • nodeDown (on by default)

  • nodeLostService (on by default)

You can turn them on and off in the Event Management  Configure Notifications  Configure Event Notifications screen. See Notifications in the Deep Dive section for more information.

Configure destination paths

A destination path specifies the "who" (recipient), "when" (delay), and "how" (method) of a notification. It also specifies escalation targets. Configuring destination paths separately from individual events lets you use the same information for multiple notifications. This minimizes duplication and encourages reuse.

You must specify a destination path to receive notifications from Horizon. The Email-Admin destination path is defined by default, and is the notification path when no other destination paths are specified. It sends email notifications to users in the Admin group.

This example specifies a destination path that sends notifications to users in the Admin group (currently just the admin user) and to an email address that you specify.

  1. Click the Gear symbol in the top-right of the screen.

  2. Under Event Management, click Configure Notifications.

  3. Under Configure Notifications, click Configure Destination Paths.

  4. Click New Path and configure it:

    1. Specify a name for the path (for example, Email-Bob) and define an initial delay.

    2. Click Edit.

    3. Under Send to Selected Groups, choose Admin.

    4. Click Add Address, type an email address in the box, and click OK

      The address appears in the Send to Email Addresses list.

    5. Click Next Step.

    6. (Optional) Define a delay interval for group notification. This will determine the delay between sending notifications to each member of a group.

      For example, defining a five minute delay will mean that, when a notification is generated, the first member of the group will be notified immediately. Subsequent members will then be notified in five-minute increments, from the top of the list of group members to the bottom.

    7. Click Next Step.

    8. Select javaEmail from the list of commands and make sure it is on.

    9. Click Next Step.

      The Admin group and the email address you specified appear in the Initial Targets list.

  5. Verify the settings, and click Finish.

You can define multiple notifications for the same unique event identifier (UEI) to use different destination paths. By default, Horizon runs the destination path of all notifications matching the event’s UEI. You can configure notifd to process only the destination path of the first matching notification by editing ${OPENNMS_HOME}/etc/notifd-configuration.xml and setting match-all="false" in the top-level notifd-configuration element.

Configuration of destination paths is stored in ${OPENNMS_HOME}/etc/destinationPaths.xml. Changes to this file happen immediately, with no need to restart Horizon.