フリー問題

問題文

The team wants every future version to be comparable against its predecessor without a manual effort each time. Which mechanism produces that?

選択肢

1. A dashboard that shows the current version's metrics, so that the previous version's numbers can be read off the very same panels from a week earlier.
2. A rule that each version must be exposed to 10 percent of live traffic for a week before the next one is prepared; a comparison made on live traffic reflects the real distribution, and a fixed exposure rule removes the need to maintain a stored set of requests.
3. A stored set of production requests replayed automatically against each candidate, with the results and the environment recorded per version.
4. A requirement that each release note state what changed, so that the difference between two versions can be read from the notes when a comparison is needed.