PCA PCA Storage & Retention 2

Question 1

Which Prometheus feature enables long-term metric storage by sending data to an external system?

Accepted Answer

remote_write

Answer

remote_write streams scraped metrics to an external storage backend like Thanos, Cortex, or VictoriaMetrics for long-term retention.

Question 2

What does Prometheus TSDB compaction do?

Accepted Answer

Merges and deduplicated smaller blocks into larger, more efficient blocks

Answer

Compaction merges multiple small blocks into larger ones and removes deleted or out-of-order samples to improve query efficiency.

Question 3

What is a Prometheus 'block' on disk?

Accepted Answer

An immutable directory containing chunks, an index, and metadata for a fixed time range

Answer

A TSDB block is an immutable directory holding compressed chunk files, an inverted index, and a meta.json describing its time range.

Question 4

Which flag controls how long Prometheus retains data when using time-based retention?

Accepted Answer

--storage.tsdb.retention.time

Answer

The --storage.tsdb.retention.time flag specifies the maximum age of data blocks before they are deleted.

Question 5

What is Prometheus federation primarily used for in storage contexts?

Accepted Answer

Allowing one Prometheus server to scrape metrics from another Prometheus server

Answer

Federation lets a higher-level Prometheus scrape aggregated or selected metrics from one or more other Prometheus instances.

(PCA) Prometheus Certified Associate Practice Test