Open Source Summit Europe 2022

So you have OpenTelemetry tracing working, but how good is the data contained in the traces? Have you ever had a production issue, looked at the trace and thought “I still can’t tell what is going on!”. We need QA for our Traces… or at least a process that drives them to improve over time. Trace-based testing is a technique that is becoming popular to test systems at an integration or end-to-end level by applying assertions against the data contained in an OpenTelemetry (OTel) trace. Trace-based testing provides much deeper testing than traditional black box testing because it takes advantage of the richness of the information contained in the trace. We will demonstrate via a live coding exercise that utilizing trace-based testing not only allows you to quickly increase test coverage, but the practice results in improved traceability. In this session, Ken will look at a failure scenario and the associated trace. He will then work through the process of creating a trace based test to cover this scenario, improving the OTel instrumentation as part of this process. With the test completed, he will show how the addition of the data also improves the trace, increasing observability.