OTSpanContex.toTraceId() truncates 128-bit TraceIds to 64-bit decimal.

[LeifW]

The toTraceId() method on OTSpanContext calls .toString() on the DDTraceId, which the Javadoc for says "Returns a 64-bit only decimal String representation of the DDTraceId".
So how do we get the original 128-bit hexadecimal TraceId?

[PerfectSlayer]

Hello @LeifW

You cannot get the 128-bit trace identifier from the OpenTracing API. You will only have the 64 lower bits as an integer.
What is your use case that needs it?

[LeifW]

We're using Datadog toTraceId wrapped in the Natchez library here: https://github.com/typelevel/natchez/blob/main/modules/datadog/src/main/scala/DDSpan.scala#L82
Would like to get that value as a string for correlating traceIds in our logs.

[PerfectSlayer]

It seems you are using the dd-trace-api dependency too, right?
If so, you can call the static methods CorrelationIdentifier.getTraceId() and CorrelationIdentifier.getSpanId() to get the IDs to inject into logs.

OpenTelemetry API will also support the 128-bit trace IDs, but OpenTracing will only give you access to the first 64-bit.