Documentation Beyla Configure Sample traces

Configure Beyla OpenTelemetry trace sampling

Beyla accepts the standard OpenTelemetry environment variables to configure the sampling ratio of traces.

In addition, you can configure the sampling under the sampler YAML subsection of the otel_traces_export section. For example:

yaml Copy

otel_traces_export:
  sampler:
    name: "traceidratio"
    arg: "0.1"

If you are using the Grafana Alloy as your OTEL collector, you can configure the sampling policy at that level instead.

Specifies the name of the sampler. It accepts the following standard sampler names from the OpenTelemetry specification:

• always_on: samples every trace. Be careful about using this sampler in an application with significant traffic: a new trace will be started and exported for every request.
• always_off: samples no traces.
• traceidratio: samples a given fraction of traces (specified by the arg property that is explained below). The fraction must be a real value between 0 and 1. For example, a value of "0.5" would sample 50% of the traces. Fractions >= 1 will always sample. Fractions < 0 are treated as zero. To respect the parent trace’s sampling configuration, the parentbased_traceidratio sampler should be used.
• parentbased_always_on (default): parent-based version of always_on sampler (see explanation below).
• parentbased_always_off: parent-based version of always_off sampler (see explanation below).
• parentbased_traceidratio: parent-based version of traceidratio sampler (see explanation below).

Parent-based samplers are composite samplers which behave differently based on the parent of the traced span. If the span has no parent, the root sampler is used to make sampling decision. If the span has a parent, the sampling configuration would depend on the sampling parent.

Specifies the argument of the selected sampler. Currently, only traceidratio and parentbased_traceidratio require an argument.

In YAML, this value MUST be provided as a string, so even if the value is numeric, make sure that it is enclosed between quotes in the YAML file, (for example, arg: "0.25").