Propagate X-Ray tracing header

[Morras]

According to the custom runtime documentation, the processing task should

Propagate the tracing header – Get the X-Ray tracing header from the Lambda-Runtime-Trace-Id header in the API response. Set the _X_AMZN_TRACE_ID environment variable locally with the same value. The X-Ray SDK uses this value to connect trace data between services.

Without the _X_AMZN_TRACE_ID the X-Ray SDK cannot create subsegments which essentially means X-Ray cannot be used with Lambda functions running with this graalvm runtime.

[mfriesen]

@Morras should be fixed in 2.2.0 release. Please let me know if that fixes your issue.

[Morras]

Thank you so much for looking at this @mfriesen .

Unfortunately it does not work.

The X-Ray SDK is reading the value from the environment variables and not the system properties.
For reference the relevant SDK code is line 40 of this class and line 49-52 is the error I am getting when I run the Lambda function on graalvm.

Unfortunately there does not appear to be an easy way of changing environment variables at runtime from Java.
Work arounds are discussed in this StackOverflow post. Considering this would only need to work on Lambda's Linux environment, a workaround might be possible, but not that pretty.

[mfriesen]

Hopefully this PR will get merged and the issue should be solved. aws/aws-xray-sdk-java#251

[mfriesen]

Waiting on aws/aws-xray-sdk-java#251 to be released. This should be fixed for aws-xray-sdk-java > 2.8.0

[Morras]

We are running a fork of the next version of aws-xray-sdk-java to get this functionality, and I can confirm that this works with that version.