New output tag in internal metrics

Adding an output tag for component_sent_* metrics

In light of our work to support multiple output streams for components, we’ve added an output tag in the following metrics emitted by sources and transforms to ensure a seamless observability experience. You will not see the output tag for sink metrics because sinks currently do not use multiple outputs.

  • component_sent_events_total
  • component_sent_event_bytes_total
  • events_out_total (Note, this metric is deprecated in favor of the above)

For example, the remap transform has a default output and an optionally enabled dropped output. The default output is specified simply as the <component_id> while the dropped output is specified as <component_id>.dropped in downstream components. Metrics for events sent to the default output will include a tag output: _default. Metrics for events sent to the dropped output will include a tag output: dropped. In general, all sources and transforms will use output: _default in metrics for events sent to their default output.


For user-defined outputs, the output tag will be populated accordingly with the user’s custom output name. Importantly, to avoid naming collisions, _default is now a reserved name and cannot be used for user-defined outputs. The route transform is the only component that currently supports custom outputs (each configured route is an output).

Components that can currently use multiple outputs include:

You can view information about all of a component’s outputs on its documentation page.