Types of graphs

Centreon Broker handles most existing RRD graph types. It can handle ABSOLUTE, COUNTER, DERIVE and GAUGE graphs as described in the .. _rrdcreate man page: http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html .

Performance data syntax

For this purpose, Centreon Broker enhanced the existing Nagios’ performance data syntax. The standard syntax is like this:

label=valueUOM;warn;crit;min;max

Where UOM is the unit, warn the warning threshold, crit the critical threshold, min the minimal value and max the maximal value.

The new enhanced syntax is as such:

type[label]=valueUOM;warn;crit;min;max

Where type is one of a, c, d or g for ABSOLUTE, COUNTER, DERIVE or GAUGE, respectively. When using the new syntax, the square brackets are required around the label. However, Centreon Broker still recognises the old syntax in which case it assumes that the graph is of the GAUGE type.

Let’s take an example:

c[total_traffic_in]=123456789B;;;0;4294967296

In the case above, the total_traffic_in metric is of type COUNTER. Its value is currently 123456789 and its unit is B (bytes). Its value range from 0 (min) and 4294967296 (max). Warning and critical thresholds are not specified.

Database relationship

The type of the metric in specified by the data_source_type field of the metrics table. This table is filled by storage endpoints. The data_source_type field is set only when a new metric is inserted in the table. This means that if you modify the performance data format of an existing metric, its type won’t be updated. To achieve metric type change you need to either use Centreon and force the metric type or follow the following steps:

  • update the data_source_type field of the target metric entry in the metrics table
  • make Broker aware of this change (restart, SIGHUP)
  • rebuild the graph