Owl Monitoring System -- Manager Installation Manual -- Defining Graphs

|  | ## Owl Monitoring System ## Manager Installation Manual

### 5. Defining Graphs

| 5.1. |  | Graphing with nagiosgraph
| 5.2. |  | Graphing with drraw.cgi
| 5.3. |  | Adding Graphs to the Nagios Sidebar

After Owl sensor data has been gathered for several hours and rrdtool has been adding it to the RRD databases, you can consider how you will graph the data. Graphing capabilities are provided by nagiosgraph and drraw.cgi. Both are very useful and have their place in your Owl monitor. It isn't a question of which to use; the question is how you want to use each and how you want to display your monitoring data.

### 5.1. Graphing with nagiosgraph

nagiosgraph provides menus for easy selection of data, available through three CGI scripts. These are simple graphs that only display a single sensor/root server/DNS record per graph. For these scripts, the host is an Owl sensor and the service is a root server/DNS record type. Links for these scripts are included in the example-side.php file.

- show.cgi - Provides graphs for a user-selected host/service pair. A graph is provided for the current day, week, month, and year.

- showhost.cgi - Provides graphs for a user-selected host. A graph will be displayed for any service with that host. A graph is provided for the current day, week, and month.

- showservice.cgi - Provides graphs for a user-selected service. A graph will be displayed for any host with that service. A graph is provided for the current day, week, and month.

### 5.2. Graphing with drraw.cgi

drraw.cgi provides a much more complex graphing capability than is available through nagiosgraph. It allows data from multiple sensor/root server/DNS record groups to be displayed on a single graph. Set-up for the graphs is not difficult and is done through a browser-based interface. However, there are a number of things that must be specified before the graph can be displayed.

The graph-definition webpage talks about selecting data sources to be displayed. This is referring to the group of RRD databases you want drraw.cgi to use for this particular graph.

Defining simple graphs, even those with multiple data sources, is not complicated. However, you can define fairly involved graphs (e.g., averaging data from different databases) with drraw.cgi.

### 5.3. Adding Graphs to the Nagios Sidebar

The share/side.php script builds the left sidebar of links on the Nagios page. Several simple modifications will improve access to the graphing facilities. Obviously, this step must wait until after the system has been set up and site-specific graphs have been defined.

The example-side.php file (in the Owl manager distribution) contains sample lines for both drraw.cgi and nagiosgraph. Add the contents of this file to the share/side.php file after the "Quick Search" text-entry box.

The sample lines must be modified for your installation in the following ways:

- The paths in the links must match the way you installed it.

- If links to specific drraw.cgi graphs are to be included in the sidebar, then the graph id in the link must be set. The id for a particular graph may be found from the graph's URL, and is the field following "Graph=".

Section 4. Adding Sensors | Owl Monitoring System Manager Installation Manual | Section 6. Changing Queries on Existing Owl Sensors

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