問題文
The store's payment integration has a thread pool. Which set of measurements does the Prometheus project's instrumentation guidance identify as the key metrics for a thread pool?
選択肢
- The identifier of each thread as a label on a single gauge, so that the state of every worker can be inspected individually.
- The number of exceptions thrown inside worker threads, because that is the only signal that distinguishes a healthy pool from an unhealthy one under load.
- The number of queued requests, the number of threads in use, the total number of threads, the number of tasks processed, and how long they took.
- The processor and memory consumption of the process, because a saturated pool always shows up as resource pressure first.