Nagios

To create accounts, you must first make yourself the root user and then create a new nagios user account and give it a password.

Its a command-line utility that allows you to view current statistics for a running Nagios process.

Nagios also used to only poll information from its target hosts, but now has plug-ins that run agents on target hosts.

This section discusses some things to consider when you attempt to optimize Nagios to improve server performance.

Nagios will use the global thresholds for flap detection if you do not specify host- or service-specific thresholds.

In this article, I focus on Nagios, an open source host, service, and network monitoring program for your Ajax applications.

If you have problems installing, take a look at the Nagios Web page (see Resources for a link) and join the mailing list.

Add Nagios to the list of system services and have it automatically start when the system boots, as shown in Listing 9.

Such an application might receive notifications from other sources, aggregate them, and pass a computed summary to Nagios.

What makes Nagios plug-ins so exciting is the ease with which they're written and shared.

Encrypt communication channels between Nagios installations and between Nagios servers and your monitoring agents.

Nagios can also assume a service is down if it has not received notifications in some period of time.

The most exciting aspect of Nagios is that writing your own plug-ins is simple and requires learning only a few easy principles.

The NOC can be alerted of system failures or see a shiny red error light on the Nagios Web interface.

The open source Nagios project (see Resources) solves complex monitoring and notification requirements quite handily.

So, I'm going to talk about Ganglia and Nagios, two tools that monitor data centers.

Add both the nagios user and the apache user to this group, as shown in Listing 2.

Storing information from Nagios in a database will allow for quicker retrieval.

To store the downloads, first create a directory like shown in Listing 3.

The final step of Nagios configuration is definition of services for the configured hosts.

Do not run Nagios as a root.

The opportunity to write your own plug-ins makes it possible to monitor everything that your Nagios server can communicate with.

Before you install Nagios, use yum to install Apache, the CC compiler, and the GD development libraries.

From the monitoring host, Nagios can monitor the CPU, disk usage, memory usage, and other local resources on remote machines.

Nagios is an open source monitor that watches servers, services, resources, and more.

I discuss how you can quickly install and start Nagios, access CGIs, and monitor hosts and services.

Event Broker API - An API has been created to allow individual developers to create addons that integrate with the core Nagios daemon.

It is more concerned with gathering metrics and tracking them over time compared with Nagios's focus as an alerting mechanism.

Another Nagios feature worth your attention is the passive check.

First notice the inheritance scheme of Nagios objects.

This is useful for processing security alerts as well as redundant and distributed Nagios setups.

Ganglia is more concerned with gathering metrics and tracking them over time while Nagios has focused on being an alerting mechanism.

Then, install the Nagios Web config file in the Apache conf. d directory by typing make install-webconf.

Nagios offers pager and e-mail notifications by default.

You will need to modify sample scripts in the eventhandlers subdirectory of the Nagios distribution.

When you restart Nagios, you now can do alerts on Ganglia metrics!

Nagios has a built-in notification system.

Navigate to the Nagios Web site and download Nagios from this site.

While they give you the basic command-line options, you can add other options as listed in the Nagios Plugin Manual.

So you never have to face incompleteness, I'll show you how to extend Nagios to monitor a network switch.

With Nagios there are many ways to accomplish a single task.

Finally, if there are no errors, start Nagios.

In this two-part article, I will discuss Ganglia and Nagios since there is some anecdotal evidence that these are the most popular.

Now, you need to register this command so that Nagios knows how to invoke it.

"Build in alerts and monitoring" : Maurya uses nagios and ganglia to get notified of any abnormal dips in system usage

When finished, you restart Nagios and you can see that I can now view my switch entries

Part 2 in this two-part series explores setting up Nagios and integrating it with Ganglia, including

Nagios (tested with version 3. 0. 6)