Observability Engineering

Chapter 6. Stitching Events into Traces

In the previous chapter, we explored why events are the fundamental building blocks of an observable system. This chapter examines how you can stitch events together into a trace. Within the last decade, distributed tracing has become an indispensable troubleshooting tool for software engineering teams.

Distributed traces are simply an interrelated series of events. Distributed tracing systems provide packaged libraries that “automagically” create and manage the work of tracking those relationships. The concepts used to create and track the relationships between discrete events can be applied far beyond traditional tracing use cases. To further explore what’s possible with observable systems, we must first explore the inner workings of tracing systems.

In this chapter, we demystify distributed tracing by examining its core components and why they are so useful for observable systems. We explain the components of a trace and use code examples to illustrate the steps necessary to assemble a trace by hand and how those components work. We present examples of adding relevant data to a trace event (or span) and why you may want that data. Finally, after showing you how a trace is assembled manually, we’ll apply those same techniques to nontraditional tracing use cases (like stitching together log events) that are possible with observable systems.

Distributed Tracing and Why It Matters Now

Tracing is a fundamental software debugging technique ...