What happened:

• Jaeger tracing was added to ACA, with the hope of having a end to end tracing from Alcor Services(such as NCM) all the way to ACA, for better analyzing and understanding of the system behavior. However, the tracing spans for ACA aren't connected to the tracing spans for NCM(and other upstream services such as the Test Controller). For more details, please visit: this Alcor PR

We suspect the un-connected tracing spans are caused by NCM(and Alcor Services) uses the opentracing libraries, and ACA, on the other hand, uses opentelemetry libraries. We suspect that by replacing the opentracing libraries with opentelemetry libraries, this problem might be solved.

Links for the libraries:

1. gRPC Tracing in NCM using opentracing
2. gRPC Tracing using opentelemetry in Java(for Alcor Services)
3. gRPC Tracing using opentelemetry in Cpp(for ACA)

If you compare the libraries, you can see that the syntax in 2 and 3 are very similar, and 1 is pretty distict from the other two. So, we have a good reason that this libraries mismatch might be the cause of those un-connected spans.

If you wish to take a look with the ACA with Jaeger added, please visit this branch of ACA