Last year, the OpenTelemetry project introduced OTTL context inference for the transform processor. The goal was to allow users to write OTTL statements without worrying about internal telemetry contexts.
Starting with collector-contrib v0.146.0, context inference is available in the Filter Processor through four new top-level config fields: trace_conditions, metric_conditions, log_conditions, and profile_conditions.
In this post, we’ll look at what context inference means specifically for filtering: how it simplifies configuration and how evaluation works.

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OpenTelemetry collector-contrib v0.146.0 introduces OTTL context inference to the Filter Processor, previously only available in the Transform Processor. Four new top-level config fields — trace_conditions, metric_conditions, log_conditions, and profile_conditions — let users write flat condition lists without manually organizing them into context blocks like resource, span, or spanevent. The processor automatically infers the execution context from path prefixes, combines conditions with logical OR, and executes them hierarchically (higher-level matches short-circuit lower-level evaluation for performance). Advanced grouping with per-group error_mode settings is also supported. The legacy configuration format remains fully supported.

OTTL context inference comes to the Filter Processor

The new approach: Conditions with OTTL context inference