Correlation String Transportation

Your application needs to pass the correlation string, generated by the tracer, to correlate a business transaction between multiple services. The correlation string must be serialized and communicated alongside the application payload.

Inbound HTTP Calls

If you pass the correlation string through an HTTP call, the string is passed as an HTTP header. The tracer searches for the key that holds the correlation header string in your function's invocation object. Correlation occurs when the Serverless Tracer finds the correlation header key. If the key cannot be found, the tracer creates a new business transaction.

Other Protocols

For protocols other than HTTP, you need to define protocol-specific transportation of the correlation string to enable business transaction correlation.

The tracer creates a new business transaction if:

  • You have not arranged for the correlation string to be passed, or
  • The tracer cannot find the correlation string.

To get started, see Set Up the Serverless APM Environment.