njmon_exporter

Prometheus exporter for IBM AIX systems running njmon.

WIP - This exporter is currently in development.

• Create a TCP server for inbound njmon connections
• Export initial metrics to Prometheus exporter format and serve them
• Add support for a yaml configuration file
• Register an exporter port in the Prometheus Wiki
• Support command line flags
• Logging
• Config validation support
• Provide decent unit test coverage
• Add a method for appending labels to selected source hosts (E.g. Dev vs. Prod)
• Declare it ready for use

Overview

njmon_exporter provides an interface between Prometheus and the AIX njmon tool (http://nmon.sourceforge.net/pmwiki.php?n=Site.Njmon). It listens for the connections described below:

• njmon instances running on IBM AIX systems (Default port: 8086)
• Promtheus scrapes (Default port: 9772)

Installation

Install and run the exporter

• Compile the Go code to create an njmon_exporter binary for your system.
• Choose a Linux VM to host the exporter
• Copy over the compiled binary to somewhere sane. E.g. /usr/local/bin/njmon_exporter
• Copy the example njmon_exporter.yml file from the repository to your preferred configuration directory. E.g. /etc/prometheus/njmon_exporter.yml.
• Test the exporter: /usr/local/bin/njmon_exporter --config /etc/prometheus/njmon_exporter.yml

Configure your prometheus.yml

• Create a new section for njmon with content something like this:

- job_name: 'njmon'
    static_configs:
      - targets:
          - <exporter_host>:9772
    scrape_interval: 60s
    honor_labels: true

• Reload Prometheus to pick up the new config.

Configure njmon

• njmon can be configured to run from a crontab entry. I find this ideal but YMMV.
• Select a user account to run njmon from
• Edit the crontab (crontab -e)
• Insert a line like this: 4 * * * * /usr/local/bin/njmon -k -s 60 -i <exporter_host> -p 8086.
• Run njmon to avoid waiting for crontab to start it /usr/local/bin/njmon -k -s 60 -i <exporter_host> -p 8086
• Repeat this section for each AIX host you want to monitor

Instance Labels

Overview

The njmon_exporter includes a method for tagging incoming njmon sources by matching their hostname against a list defined in the njmon_exporter.yml config file. The concept came about following a need to identify specific hosts as Production vs. Non-Production.

Configuration

The njmon_exporter.yml file contains a section titled instance_label. There are four required parameters in this section:-

• label_name: The name of the label that will be appended to all host metrics (E.g. environment).
• label_hit: The value to associate with label_name when a hostname match occurs (E.g. prod).
• label_miss: The value to associate with label_name when an incoming hostname isn't matched (E.g. dev).
• hit_instance: A list of incoming hostnames that will trigger label_name=label_hit.

Production vs. Development is just an example. Any label can be generated and populated based on a match (or no match) of the hit_instance list.