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opentelemetry_xray
OpenTelemetry AWS X-Ray support for Erlang/Elixir.
This library includes two modules:
An id generator that creates X-Ray-compatible
trace_id
andspan_id
. It implements theotel_id_generator
protocol in the Erlang SDK.A propagator that reads and writes AWS X-Ray trace context headers. It implements the
otel_propagator_text_map
protocol in the Erlang SDK.
It assumes that you are using the AWS Distro for OpenTelemetry Collector, a version of the OpenTelemetry Collector which has support for AWS services such as X-Ray. You can run it as a sidecar container in an ECS task or as a daemon on an EC2 instance. It accepts standard OpenTelemetry traces, converts them to X-Ray format, and sends them to AWS.
In AWS X-Ray, the trace_id
is a 128-bit value. The first 32 bits are a Unix
time_t
and the rest are a 96-bit random number. If you use the default
trace_id, then X-Ray will reject your traces. This library generates ids that are compatible with X-Ray.
If your app is running behind an AWS Application Load Balancer, then the ALB will pass a trace in the
X-Amzn-Trace-Id
header. This library includes a propagator which reads the trace id from this header
and uses it to set spans for your app.
Links:
- Propagator: https://opentelemetry.io/docs/specs/otel/context/api-propagators/
- https://docs.aws.amazon.com/xray/latest/devguide/xray-concepts.html#xray-concepts-tracingheader
- https://aws-otel.github.io/docs/getting-started/x-ray#configuring-the-aws-x-ray-exporter
Since trace_context
and baggage
are the two default propagators, the
global TextMap Propagators must be configured.
configuration
Configuration
In config/config.exs
:
config :opentelemetry,
id_generator: :opentelemetry_xray_id_generator,
propagators: [:opentelemetry_xray_propagator, :baggage]
See phoenix_container_example for a complete Elixir Phoenix app that uses this library.