Send Erlang and Elixir logs and traces to Bronto

This page covers instrumenting an Erlang or Elixir application with the OpenTelemetry SDK to send logs and traces to Bronto over OTLP/HTTP via a local OTel Collector. Both signals are co-equal: logs are captured via the kernel logger handler automatically, and traces are created using the OTel API macros and functions.

If you don’t have a Collector and want to export directly from your application to Bronto, see Direct export to Bronto at the bottom of this page.

Prerequisites

Erlang/OTP 24 or later, or Elixir 1.13 or later
Rebar3 (Erlang) or Mix (Elixir)
A running OTel Collector configured to forward logs and traces to Bronto — see Connect Open Telemetry to Bronto
OpenTelemetry Erlang/Elixir SDK documentation

Install dependencies

def deps do
  [
    {:opentelemetry_api, "~> 1.4"},
    {:opentelemetry, "~> 1.4"},
    {:opentelemetry_exporter, "~> 1.7"}
  ]
end

{deps, [
  {opentelemetry_api, "~> 1.4"},
  {opentelemetry, "~> 1.4"},
  {opentelemetry_exporter, "~> 1.7"}
]}.

Package	Purpose
`opentelemetry_api`	Core OTel API
`opentelemetry`	SDK — `LoggerProvider`, processors, kernel log handler
`opentelemetry_exporter`	OTLP/HTTP exporter

Configure the log bridge

The OTel SDK ships an Erlang kernel logger handler (otel_log_handler) that captures all log events emitted via :logger (Erlang) or Logger (Elixir). Configure it in your application config.

import Config

config :opentelemetry,
  resource: [
    service: [
      name: "my-service",
      namespace: "my-team"
    ],
    "deployment.environment": "production"
  ],
  logs_exporter: :otlp

config :opentelemetry_exporter,
  otlp_protocol: :http_protobuf,
  otlp_logs_endpoint: "http://localhost:4318/v1/logs"

[
  {opentelemetry, [
    {resource, #{
      <<"service.name">>      => <<"my-service">>,
      <<"service.namespace">> => <<"my-team">>,
      <<"deployment.environment">> => <<"production">>
    }},
    {logs_exporter, otlp}
  ]},
  {opentelemetry_exporter, [
    {otlp_protocol, http_protobuf},
    {otlp_logs_endpoint, "http://localhost:4318/v1/logs"}
  ]}
].

No code changes are required — the kernel logger handler is installed automatically when the opentelemetry application starts.

Set resource attributes

Resource attributes are attached to every log record exported from this process. Two attributes drive how Bronto organises incoming logs:

OTel attribute	Bronto concept	Description
`service.name`	Dataset	Groups logs from one service
`service.namespace`	Collection	Groups related services or a team’s services

These are set via the resource config key in the setup above.

Complete example

# Existing Logger calls work unchanged
require Logger

Logger.info("Application started")
Logger.warning("Low disk space", disk_free_gb: 2.1)
Logger.error("Database connection failed", reason: :timeout)

%% Existing logger calls work unchanged
?LOG_INFO("Application started"),
?LOG_WARNING("Low disk space ~p GB free", [2.1]),
?LOG_ERROR("Database connection failed: ~p", [timeout]).

Existing Logger / :logger calls require no changes. The OTel handler runs alongside any existing handlers (console, file) configured in your kernel logger setup.

Verify delivery

After running your application, check both signals in Bronto:

Logs: open the Search page and filter by the dataset name you set in service.name — your log records should appear within a few seconds.
Traces: open the Explore Traces page and filter by the same service.name — your spans should appear within a few seconds.

If no logs appear, check:

The OTel Collector is running and reachable at the configured endpoint.
The Collector’s pipeline includes a logs pipeline with an otlp receiver and the Bronto exporter — see Connect Open Telemetry to Bronto.
The opentelemetry application is started before your application (listed in extra_applications or applications in your .app.src/mix.exs).

Traces

Framework-specific instrumentation libraries are available for Phoenix, Ecto, LiveView, Absinthe, and more — add opentelemetry_phoenix, opentelemetry_ecto, etc. to your deps and they instrument those frameworks automatically. See Erlang/Elixir instrumentation libraries for the full list.

Configure tracing

Tracing is included in the same opentelemetry and opentelemetry_exporter packages — no additional dependencies are needed. Add the traces endpoint to your config:

config :opentelemetry,
  resource: [
    service: [name: "my-service", namespace: "my-team"],
    "deployment.environment": "production"
  ],
  traces_exporter: :otlp,
  logs_exporter: :otlp

config :opentelemetry_exporter,
  otlp_protocol: :http_protobuf,
  otlp_traces_endpoint: "http://localhost:4318/v1/traces",
  otlp_logs_endpoint: "http://localhost:4318/v1/logs"

{opentelemetry, [
  {resource, #{
    <<"service.name">>      => <<"my-service">>,
    <<"service.namespace">> => <<"my-team">>,
    <<"deployment.environment">> => <<"production">>
  }},
  {traces_exporter, otlp},
  {logs_exporter, otlp}
]},
{opentelemetry_exporter, [
  {otlp_protocol, http_protobuf},
  {otlp_traces_endpoint, "http://localhost:4318/v1/traces"},
  {otlp_logs_endpoint, "http://localhost:4318/v1/logs"}
]}

Creating spans

require OpenTelemetry.Tracer, as: Tracer

Tracer.with_span "process-payment" do
  Tracer.set_attributes([{"payment.amount", 99.99}, {"payment.currency", "USD"}])
  Logger.info("Processing payment")  # trace_id and span_id injected automatically
end

?with_span(<<"process-payment">>, #{}, fun(_SpanCtx) ->
  ?set_attributes([{<<"payment.amount">>, 99.99}]),
  ?LOG_INFO("Processing payment")
end)

Any log emitted inside a span will automatically have trace_id and span_id attached.

Direct export to Bronto

If you are not using an OTel Collector, export directly to Bronto by replacing the exporter endpoints and adding your API key:

config :opentelemetry_exporter,
  otlp_protocol: :http_protobuf,
  otlp_logs_endpoint: "https://ingestion.eu.bronto.io/v1/logs",
  otlp_traces_endpoint: "https://ingestion.eu.bronto.io/v1/traces",
  otlp_headers: [{"x-bronto-api-key", "<YOUR_API_KEY>"}]

{opentelemetry_exporter, [
  {otlp_protocol, http_protobuf},
  {otlp_logs_endpoint, "https://ingestion.eu.bronto.io/v1/logs"},
  {otlp_traces_endpoint, "https://ingestion.eu.bronto.io/v1/traces"},
  {otlp_headers, [{<<"x-bronto-api-key">>, <<"<YOUR_API_KEY>">>}]}
]}

Region	Logs endpoint	Traces endpoint
EU	`https://ingestion.eu.bronto.io/v1/logs`	`https://ingestion.eu.bronto.io/v1/traces`
US	`https://ingestion.us.bronto.io/v1/logs`	`https://ingestion.us.bronto.io/v1/traces`

See API Keys for how to create a key with ingestion permissions. No other changes to the rest of the setup are required.

​Prerequisites

​Install dependencies

​Configure the log bridge

​Set resource attributes

​Complete example

​Verify delivery

​Traces

​Configure tracing

​Creating spans

​Direct export to Bronto

Prerequisites

Install dependencies

Configure the log bridge

Set resource attributes

Complete example

Verify delivery

Traces

Configure tracing

Creating spans

Direct export to Bronto