PCA (Prometheus Certified Associate) sample exam question with answer 182

Question:
Which of the following is a valid use case for the "unless" binary operator in PromQL?

1. Filtering time series data based on label values
2. Calculating the rate of change of a metric over time
3. Combining multiple time series data
4. Evaluating whether a metric does not meet a certain threshold value

Answer:
D - The unless binary operator in PromQL is used to evaluate whether a metric does not meet a certain threshold value. It is used in combination with the ==, !=, >, <, >=, or <= operators to negate the result of the comparison