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.
It needs Roadrunner 0.16. 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}]}].Using Elixir or Gleam? See the Elixir and Gleam guides.
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.
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.
roadrunner_telemetry is open source and maintained on personal time. If you or your company find it useful, consider sponsoring.
I also accept coffees ☕
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.
Copyright (c) 2026 William Fank Thomé
roadrunner_telemetry is open-source under the Apache 2.0 License on GitHub.
See LICENSE.md for more information.