Graphing Performance Info With PNP4Nagios
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## Graphing Performance Info With PNP4Nagios

Introduction

The icingastats utility allows you to graph various Icinga performance statistics over time using PNP4Nagios. This is important because it can help you to:

- Ensure Icinga is operating efficiently

- Locate problem areas in the monitoring process

- Observe the performance impacts of changes in your Icinga configuration

Prerequisites

PNP4Nagios is one of the most popular addons due to easy installation and little maintenance during operation. The documentation along with further links to download the software can be found at http://docs.pnp4nagios.org/pnp-0.6/start.

check_nagiostats was published by Jochen Bern and can be called as an active service check or via crontab to submit passive check results. Despite its name it can be used for Icinga as well.

- After downloading the plugin and placing it into the plugin directory (e.g. `/usr/local/icinga/libexec` if you used the quickstart installation guides) you have to check the values of the configuration section within the script.

  - Most important is "`EXEC=``/path/to/icingastats`" (e.g. `/usr/local/icinga/bin/icingastats`) pointing to the `icingastats` binary.

  - Depending on your likings you may want to change the value of `CUMULATE` from "AVG" to "MIN" or "MAX", respectively. The setting of `TIMEFRAME` influences the timeperiod which will be used for cumulated values in the output of the plugin.

  - Changing the values of `PASSIVE_EMERGENCY_HOST` and `PASSIVE_EMERGENCY_SERVICE` shouldn't be necessary because you pass the values as arguments to the script.

- You can call the plugin using active or passive checks

  - Active

    Make sure that your object configuration files contain a matching service definition such as

         define service{
            host_name               <the Icinga server>
            service_description     icingastats # (or something appropriate)
            check_command           check_stats
            check_interval          1
            retry_interval          1
            ...
         }

    and a command definition

         define command{
            command_name            check_stats
            command_line            $USER1$/check_nagiostats
         }

    Don't forget to restart Icinga after these changes.

  - Passive

    Make sure that your object configuration files contain a matching service definition such as

         define service{
            host_name               <the Icinga server>
            service_description     icingastats # (or something appropriate)
            active_checks_enabled   0
            check_command           check_stats!3!Freshness threshold exceeded
            check_freshness         1
            freshness_threshold     180         # check interval + x seconds
            ...
         }

    and a command definition

         define command{
            command_name            check_stats
            command_line            $USER1$/check_dummy $ARG1$ $ARG2$
         }

    Don't forget to restart Icinga after this change.

    Add a line to the crontab of the Icinga user which will call the `icingastats` binary and submit the results to the command pipe

         * * * * * /usr/local/icinga/libexec/check_nagiostats --passive <host> icingastats >> /usr/local/icinga/var/rw/icinga.cmd

    This way the values are updated in regular intervals.

- Create a symbolic link in the (user) templates folder of PNP4Nagios

       $> ln -s ../templates.dist/nagiostats.php check_stats.php

  Make sure that check_stats (without the extension .php) matches the value you specified as first parameter in the check_command.

Example Graphs

We'll describe what the graphs produced by `check_nagiostats` mean and what they can be used for...

Average Host / Service Check Latency

Figure 8.1. Average Host / Service Check Latency

This graph shows the average latency times of hosts and services over time for both active and passive checks, respectively. Useful for understanding:

- Host checks

- Service checks

- Active checks

- Passive checks

- Performance tuning

Consistently high latencies can be an indication that one or more of the following variables need tweaking:

- max_concurrent_checks

- check_result_reaper_frequency

- max_check_result_reaper_time

Service Statistics

Figure 8.2. Service Statistics

This graph shows the values for the several service states along with the average number of services being checked actively/passively within the timeperiod you specified. Useful for understanding:

- Service checks

- Predictive service dependency checks

- Cached checks

- Flap detection

Host Statistics

Figure 8.3. Host Statistics

This graph shows the values for the several host states along with the average number of hosts being checked actively/passively within the timeperiod you specified. Useful for understanding:

- Host checks

- Predictive host dependency checks

- Cached checks

- Flap detection

Average Execution Times

Figure 8.4. Average Execution Times

This graph shows the average execution times of hosts and services over time. Useful for understanding:

- Host checks

- Service checks

- Performance tuning

| Note
To be honest: We tweaked the graphs a bit, meaning the colours. Yellow is sometimes hard to distinguish from the background so we changed some lines in the PNP4Nagios template file `template.dist/nagiostats.php` from `$i=0;` to `$i=1;`.

Additional graphs

Well, we tweaked the template a bit more because the plugin delivers the data but there aren't appropriate graphs (but looking at the template file it is very easy to add the lines if you really need the following graphs).

External Commands

Figure 8.5. External Commands

This graph shows how may external commands have been processed by the Icinga daemon over time. Unless you're processing a large number of external commands (as in the case with distributed monitoring setups), this graph may appear mostly empty. Monitoring external commands can be useful for understanding the impacts of:

- Passive checks

- Distributed monitoring

- Redundant/failover monitoring

External Command Buffers

Figure 8.6. External Command Buffers

This graph shows how many external command buffer slots are in use over time. If the number of used buffers is near the number of available buffers on a regular basis, it is likely you need to increase the available external command buffer slots. Each buffer slot can hold one external command. Buffers are used for temporarily holding external commands from the time they are read from the external command file to the time they are processed by the Icinga daemon.

As you can see just one buffer is used and that's the one for the graphs as mentioned above.

Cached Host and Service Checks

Figure 8.7. Cached Host and Service Checks

This graph shows how may cached host and service checks have occurred over time. Useful for understanding:

- Cached checks

- Predictive host and service dependency checks

Average State Changes

Figure 8.8. Average State Changes

This graph shows the average percent state change (a measure of volatility) over time, broken down by hosts and services that were last checked either actively or passively. Useful for understanding:

- Flap detection

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