WHY OBSERVABILITY MATTERS

STARTING SMALL AND GROWING You do not need an expensive platform on day one. A harness that writes one line of structured text per event to a file is already a big step beyond having nothing. Begin with the basics listed above, look at the data every week, and add detail only when a real question cannot be answered. In the Practice Lab you will add exactly this kind of recording in Chapter 68. QUESTIONS OBSERVABILITY SHOULD ANSWER A useful way to decide what to build is to list the questions you will ask on a bad day. Why did this particular run fail? Which tool fails most often, and what error does it give? Did the answer get worse after last week's change? Which users or task types are hurt most? How much does a typical run cost, and which runs cost far more than that? If your data can answer these questions, it is good enough. If it cannot, the missing item tells you exactly what to start recording.