roadrunner_telemetry

telemetry events for Roadrunner.

Roadrunner hands its request, connection, and WebSocket events to one event handler, and drops them by default. roadrunner_telemetry is that handler: it turns every event into a telemetry event, so telemetry_metrics, Prometheus reporters, OpenTelemetry, LiveDashboard, and your own handlers can use them.

Installation

It needs Roadrunner 0.11 or later. Add it next to roadrunner in your rebar.config:

{deps, [
    roadrunner,
    roadrunner_telemetry
]}.

Make it Roadrunner's event handler in your sys.config:

[{roadrunner, [{event_handler, roadrunner_telemetry}]}].

Usage

Attach telemetry handlers as usual:

telemetry:attach(log_requests, [roadrunner, request, stop],
    fun(_Event, #{duration := D}, #{method := M, path := P, status := S}, _) ->
        Us = erlang:convert_time_unit(D, native, microsecond),
        logger:info("~s ~s -> ~p (~p us)", [M, P, S, Us])
    end, undefined).

Request events follow the telemetry span convention, with a shared telemetry_span_context, so tools that pair start and stop events work out of the box. Once your handlers are attached, telemetry:persist/0 makes the event lookup cheaper under load.

See the module documentation for every event with its measurements and metadata.

🚧 Status

roadrunner_telemetry is in 0.x. The core is functional and covered by tests, but the API may change between minor versions. Pin an exact version in your deps if you need stability across upgrades.

Contributing

Contributions are welcome! Run rebar3 precommit before opening a pull request: it checks formatting, runs xref, hank, dialyzer, and the docs build, and runs the tests with a 100% coverage gate.

License

roadrunner_telemetry is open-source under the Apache 2.0 License on GitHub.

See LICENSE.md for more information.

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