Why is it wrong to assume that every library in an application will automatically produce traces?
Select an answer to reveal the explanation.
Short Explanation
Automatic instrumentation only covers the frameworks and libraries the tracer supports. If a library isn't in that supported set, you won't get spans from it unless you instrument it manually. So don't assume every library automatically produces traces.
Full Explanation
Automatic instrumentation covers supported frameworks and libraries; anything outside that set produces no spans unless instrumented manually. Tracers instrument known entry points and clients. A custom protocol or unsupported library will simply not appear, leaving a blank stretch in the call path that is easy to misread as fast execution.
The claim that tracing is never automatic and always requires manual code changes is wrong because automatic instrumentation genuinely covers many common frameworks without code changes.
The claim that libraries produce traces only when the application runs in a container is wrong because containerisation does not determine instrumentation coverage.
The claim that traces from libraries are collected but discarded by the backend unless enabled per library is wrong because the spans are never produced in the first place rather than being discarded later.
For the exam, check library and framework coverage rather than assuming it.