PCA (Prometheus Certified Associate) sample exam question with answer 73

Question:
You are instrumenting an HTTP API with Prometheus metrics. You want to define a metric that tracks the latency of HTTP requests made to your API. You only care about the average latency and do not have a need for percentiles.
Which of the following metric names and types is the MOST appropriate for this scenario?

1. http_request_duration, Histogram
2. http_request_duration, Summary
3. http_request_duration_seconds, Summary
4. http_request_duration_seconds, Histogram

Answer:
C - check metric types and metric naming.
Histogram is incorrect as we only care about the average latency.
Thus, collecting a histogram metric with bucketed values is overkill for this scenario and will use more storage space compared to a summary metric.
Additionally, the unit of measurement should be included at the end of the metric name