In the previous chapter, we looked into the theory behind end-to-end tracing, and various architectural decisions one must make when building a distributed tracing infrastructure, including which data formats can be used for propagating metadata between processes and for exporting tracing data to a tracing backend. Fortunately, as we will see in this chapter, an end user of a tracing infrastructure, someone who wants to instrument their business application, or their open source framework, or library, typically does not need to worry about those decisions.
We only briefly touched upon the notion of instrumentation and trace points before, so in this chapter, we will dive deep into the question of instrumentation, using three canonical "Hello, World!" applications in Go, Java, and Python. You may be having Jules Winnfield's reflex right now: "Say Hello, World! again," but I promise to make it interesting.
The application will be built with...