Nagios Overview

The HP XC System Software uses the Nagios open source application to gather and display system statistics, such as processor load and disk usage. Nagios watches hosts and services and alerts you when problems occur or are resolved. HP XC System Software integrates Nagios with software packaged with the HP XC System Software including Supermon, SLURM, and LSF.

The design of the Nagios application incorporates the concept of a plug-in, that is, an independent file that extends the Nagios application. This design allows the development of service checks, which are use to examine system and network services.

Nagios, as provided with the HP XC System Software, is configured with system and network service checks already in place for your system; they were automatically configured for each node with the nagios nconfig script when the cluster_config utility was run.

The HP XC system automatically configures the Nagios environment based on the configuration of the HP XC system. Autoconfiguration is based on the information in the HP XC configuration and management database (CMDB). The configuration is updated as a result of changes to the HP XC database.

Nagios obtains most of its data from the Supermon open source monitoring application, which is integrated with the HP XC System Software.

The Nagios master can be configured for improved availability. When configured for improved availability, the head node must have the management_server role but not the management_hub role; the other node in the availability set must have the management_server role and the management_hub role. By default, the head node acts as the Nagios master and the other node in the availability set acts as a Nagios_monitor. If the head node fails, the availability tool reconfigures the other node in the availability set to act as both the Nagios master and a Nagios monitor.

You can find the complete documentation for Nagios on the Nagios Web site:

www.nagios.org

Specific information on Nagios features are available on the following Web site:

www.nagios.org/about/

Additional information on Nagios is commercially available. The following Web site lists documents that describe Nagios and its use for system and network administration:

http://www.nagios.org/propaganda/books/

“Messages Reported by Nagios” describes troubleshooting information reported by Nagios.

This section addresses the following topics:

Nagios Components

The components that comprise Nagios are as follows:

Nagios	Nagios engine Nagios Web interface Nagiostats tool
Standard Plug-Ins	These plug-ins are not configured for any particular system. Although they are all provided, not all these plug-ins are used on HP XC systems.
Additional Packages	These packages include the following: Nagios Remote Plug-In Executor (NRPE), which executes commands on nodes remotely Nagios Service Check Acceptor (NSCA), which receive Nagios status data from distributed monitors NAN, which queues and batches Nagios alerts to reduce email messages. Nagios Console Monitor (NSC), a text display monitor, based on the curses library package, for viewing Nagios data

Nagios Hosts

A Nagios host refers to any entity with an IP address, not just nodes. An interconnect switch and an HP StorageWorks Scalable File Share (SFS) server are considered Nagios hosts.

Nagios Plug-Ins

The following is a list of Nagios plug-ins provided with the HP XC System Software:

• Apache HTTPS server reports

• Configuration information

• Environment status report

• Load average status report

• LSF failover monitor

• Nagios Host monitor

• Nagios monitor

• Node information report

• Interconnect ping status report

• ProCurve switch status (cluster necs1-1)

• Resource monitor

• Resource status report

• Root key synchronization reports

• SFS appliance status

• SLURM monitor

• SLURM status report

• Supermon metrics monitor

• Switch status reports

• Syslog alert monitor

• Syslog alerts status

• System event log

• System free space status report

For more information on the services monitored by Nagios and the type of function monitored for that service, see Table 8-2.

Nagios Web Interface

Nagios provides a Web interface capable of displaying current system and networking information in a browser window. See “Using the Nagios Web Interface” for more information.

Nagios Files

The following lists the files and directories that are important to Nagios configuration for HP XC:

/opt/hptc/nagios/bin	Contains the Nagios binaries.
/opt/hptc/nagios/libexec	Contains plug-ins specific to Nagios and to the HP XC system.
/opt/hptc/nagios/etc	Contains the Nagios configuration values. NOTE: Files having file names of the form xc*.cfg and *_local.cfg are generated during and as a result of the nconfig process. Do not modify these files manually. Modify the file nagios.cfg in this directory or an appropriate file with the file name of the form *_template.cfg in the /opt/hptc/nagios/etc/templates directory.
/opt/hptc/nagios/etc/templates	Contains files that contain specific functionality drawn in based on HP XC service mappings.
/opt/hptc/nagios/var	Contains log files and the Nagios FIFO queue.