YAML File - Default Labels

The YAML file used by this client is divided into several sections, each serving a distinct purpose:

Table 1. YAML File Structure

globalVariables	Defines global variables that can be used throughout the YAML file.
defaultLabels	Sets default labels to be applied to all metrics.
metricObjects	Defines the metrics to be exposed to Prometheus, including their types and specific labels.
metricData	Specifies the data points to be collected, along with any processing functions to be applied.

Overview

Default labels are a set of key-value pairs that are automatically attached to every metric in the Prometheus Client. They provide a convenient way to include common information across all metrics.

Configuration

Defined under `defaultLabels` in the YAML file.
Applied globally to all metrics for consistent tagging.

Purpose

To ensure every metric includes essential information like environment details, version numbers, or system identifiers.
Simplifies metric queries and aggregation in Prometheus by having common labels.

Example

In this example, every metric reported by the Prometheus Client will include `environment` and `appVersion` labels.

```
defaultLabels:
  environment: "production"
  appVersion: "1.0.0"
```

Note: In the Prometheus Client configuration, default labels can dynamically reflect WinCC OA's real-time state. This functionality is enabled through YAML Commands or the `${}` notation, which allows for the integration of WinCC OA functions directly into label definitions.