フリー問題

問題文

Which sampler value keeps whole traces at a consistent rate without inspecting their content, and what is that technique called?

選択肢

1. A sampler that always keeps everything, because keeping all traces is by definition a consistent rate and therefore satisfies the same requirement at a higher cost.
2. A ratio based on the trace identifier, which is also referred to as deterministic sampling.
3. A sampler that obtains its strategy from a remote server, where a central rate applied everywhere keeps whole traces at one rate.
4. A sampler that inspects the span status, and keeping the failures and a share of the rest gives a consistent rate overall.