Your team is developing a set of Lambda functions. They need to debug the Lambda functions using the X-Ray service. Which of the following are environment variables which AWS Lambda uses to communicate with the X-Ray service? Choose 3 answers from the options given below.

Answer options:

A._X_AMZN_TRACE_ID
B.AWS_XRAY_CONTEXT_MISSING
C.AWS_XRAY_DAEMON_ADDRESS
D.AWS_LAMBDA_XRAY

Answer – A, B and C
The AWS Documentation mentions the following.
AWS Lambda uses environment variables to facilitate communication with the X-Ray daemon and configure the X-Ray SDK.
_X_AMZN_TRACE_ID: Contains the tracing header, which includes the sampling decision, trace ID, and parent segment ID. If Lambda receives a tracing header when your function is invoked, that header will be used to populate the _X_AMZN_TRACE_ID environment variable. If a tracing header was not received, Lambda will generate one for you.
AWS_XRAY_CONTEXT_MISSING: The X-Ray SDK uses this variable to determine its behavior in the event that your function tries to record X-Ray data, but a tracing header is not available. Lambda sets this value to LOG_ERROR by default.
AWS_XRAY_DAEMON_ADDRESS: This environment variable exposes the X-Ray daemon`s address in the following format: IP_ADDRESS:PORT. You can use the X-Ray daemon`s address to send trace data to the X-Ray daemon directly, without using the X-Ray SDK.
For more information on using Lambda with X-Ray, please refer to the below URL-
https://docs.aws.amazon.com/lambda/latest/dg/lambda-x-ray.html