The correct environment variable to configure is AWS_XRAY_DAEMON_ADDRESS. This variable tells the X Ray SDK where to send traces so it can discover the daemon running at a non default host and port such as 10.0.2.25 on port 3000.

When the SDK needs to emit segments it reads AWS_XRAY_DAEMON_ADDRESS to obtain the daemon host and port and this overrides the default of 127.0.0.1 on port 2000. Setting this variable in the task definition ensures the Node.js microservice sidecar pattern on ECS with Fargate routes trace traffic to the correct address.

AWS_XRAY_TRACING_NAME is not used to locate the daemon and only sets the service or tracing name that appears on segments.

AWS Distro for OpenTelemetry is a separate observability distribution and not an environment variable for the X Ray SDK so it does not control daemon discovery.

AWS_XRAY_CONTEXT_MISSING configures SDK behavior when no segment context is present and is typically set to values such as LOG_ERROR. It does not configure where the daemon runs or how the SDK connects to it.

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