PCA Metric Collection & Data Modeling 5

Question 1

What is the significance of the `_bucket`, `_sum`, and `_count` suffixes automatically created for a Prometheus Histogram?

Accepted Answer

They are the three separate time series Prometheus stores for every histogram metric

Answer

Prometheus automatically creates three time series for each histogram: `_bucket` (cumulative counts per bucket), `_sum` (total sum of observations), and `_count` (total number of observations).

Question 2

When using the Prometheus Pushgateway, which HTTP method is used to replace all metrics for a specific job and instance grouping?

Accepted Answer

PUT

Answer

PUT replaces all metrics for the specified job/instance grouping atomically, while POST only updates the provided metrics.

Question 3

What does the `up` metric that Prometheus automatically generates represent?

Accepted Answer

Whether a scrape target was successfully reached (1) or failed (0)

Answer

Prometheus automatically generates an `up` metric (value 1 for success, 0 for failure) for each scrape target to indicate scrape health.

Question 4

Which label relabeling action in Prometheus drops a target if the source label matches a given regex?

Accepted Answer

`drop`

Answer

The `drop` relabeling action removes targets from the scrape pool if the source label value matches the specified regular expression.

Question 5

A Summary metric client-side calculates quantiles over a 10-minute sliding window. What is a key limitation compared to Histograms?

Accepted Answer

Summaries cannot be aggregated across multiple instances in PromQL

Answer

Because Summary quantiles are pre-calculated client-side, they cannot be meaningfully aggregated across multiple instances using PromQL aggregation operators.

(PCA) Prometheus Certified Associate Practice Test

(PCA) Prometheus Certified Associate Practice Test

PCA Metric Collection & Data Modeling 5