Capable as the wizards are, they’re no match for the Core Config Manager (CCM) when it comes to managing existing objects and advanced settings. In this article, we’ll dig into the CCM and explore how it works, what it does, and how it’s used.

Accessing the CCM

To get to the Core Config Manager, go to Configure > Core Config Manager.

On the CCM main page, you’ll see an Object Summary of all the Core objects, a list of Recent Snapshots, and a left-hand menu full of options. Let’s explore some key functions and capabilities.

Making Small Changes

One of the most common tasks you’ll complete in the CCM is making granular changes to specific settings on your monitored hosts and services. We’ll cover a simple example here, and you can refer to the full guides for complete details:

Service management with the CCM

Host management with the CCM

If you wanted to make the check interval on a key service more aggressive, you’d simply click Services in the left-hand submenu, then do a quick search to locate your service:

Once you locate the service and click through, you’ll be brought to the Service Management section. Hit the Check Settings tab, update the Check Interval to your new setting, and click Save.

Applying Your Config

Once you’ve saved your change, you will be returned to the Services directory and will notice a banner at the top indicating you need to Apply Configuration:

Changes made in the Nagios XI user interface need to be written to the underlying Nagios Core monitoring engine in order to take effect. Apply Configuration verifies that your configuration changes are valid, then updates the Core configs.

Uh-oh… Something Went Wrong

If you apply the config and an error is detected, you’ll see a screen like this:

Don’t panic! Until you apply a working config, the Core engine will continue monitoring based on the last known good config, so your monitoring will continue uninterrupted.

In this example, we can see that our service is missing a service description. If we navigate to the Apache-Weblogger services, we can quickly spot the problem, which shows red ‘Not Applied’ text in the Status column:

Simply update the settings (in this case by adding a Service Description) and Apply Configuration again to write the changes.

Also note that each time you Apply Configuration, a snapshot is taken. These can be viewed in the Quick Tools > Configuration Snapshots section of the CCM. You can roll back to previous configurations anytime by clicking the circular arrow icon in the Actions column.

You can also review exactly what was changed by clicking the View diff button in the Diff Changes column for an entry:

Managing Groups

The CCM is also where you’ll manage your host groups and service groups, which enable you to quickly filter things like dashboards and reports to focus on specific subsets of your monitored assets and to carry out advanced approaches like hostgroup inheritance, whereby any host added to a group inherits various common services automatically. You can learn more about managing groups in this article:

Master Host and Service Groups in Nagios XI

Advanced Options

Dependencies

Host and Service Dependencies can be managed in the Advanced section of the CCM. You may already be familiar with parent/child relationships, which enable you to define host topology so that Nagios XI alerts you intelligently based on its ability to reach hosts. When a parent breaks, the child hosts and their services are marked as Unreachable rather than Critical, and you can customize whether and how Unreachable states alert.

Dependencies function in a similar way but aren’t meant to be dictated by topology alone. Any host or service can be made dependent on any other hosts or services you wish, providing a way to define advanced relationships based on the specifics of your environment. Note that, unlike Parent/Child relationships, dependencies don’t impact auto-generated topology diagrams like the Hypermap and Network Status Map.

Escalations

Host and Service Escalations provide a way to customize notifications when problems persist for too long, for example, sending an email to a manager if a host is still down after three notifications are sent to admins. These can be managed in either the Alerting > Host Escalations/Service Escalations section or via the handy Escalation Wizard in the Tools section of the CCM.

Event Handlers

Event handlers are automated actions you set XI to take when state changes occur. A simple example would be to execute a restart script on a host when Nagios detects that a key service is stopped, but ultimately, anything you can script can be done, so the possibilities are vast. This document provides full details and an example to try:

Introduction to Event Handlers in Nagios XI

Commands

These are the commands Nagios runs to do things like execute status checks, send notifications, and fire off event handlers. You’ll notice 160+ pre-loaded commands that XI uses to support the default monitoring wizards and alerting functions and can add your own as needed. This example shows the check_xi_ncpa command, which is run when Nagios executes a check on a host running the NCPA agent:

Import Config Files

If you’re currently using Nagios Core and would like to import your config files into Nagios XI, you can learn more about the process, the ready-made Import Prep Tool, and carry out the import in this section of the CCM.

Making Big Changes

The Bulk Modifications Tool has long been a favorite of Enterprise Edition users, especially those with large and dynamic environments. The tool enables you to quickly modify a key setting on as many hosts or services as you’d like with a few clicks.

Bulk Renaming not only provides a way to rename many objects at once but, even better (unlike renaming one at a time in the Core Config Manager) ensures that your historical performance data is retained even after changing the name of an object.

Give it a Try

As you can see, understanding and utilizing the CCM’s key capabilities is an important element of mastering XI administration.

If you’re not already using Nagios XI, the free trial version is a great way to experience the power of the Core Config Manager for yourself:

Nagios XI Free Trial

If you have any questions or need a hand, you can reach us at sales@nagios.com.