PCA PCA Federation & Remote Storage 3

Question 1

What is 'cross-shard' federation typically used for in large-scale Prometheus deployments?

Accepted Answer

Merging metrics from multiple Prometheus shards that each scrape a subset of targets

Answer

When a single Prometheus cannot scrape all targets, multiple shards each cover a subset; a federation layer then pulls aggregated metrics from all shards into a unified view.

Question 2

What does the 'write_relabel_configs' option inside a remote_write block allow you to do?

Accepted Answer

Filter or transform metric series before they are sent to the remote storage endpoint

Answer

write_relabel_configs applies relabeling rules to metric series just before remote_write sends them, allowing operators to drop, modify, or filter metrics destined for remote storage.

Question 3

What is the main advantage of Cortex or Thanos over a standalone Prometheus for production long-term storage?

Accepted Answer

They provide horizontally scalable, multi-tenant storage with global query capability across instances

Answer

Cortex and Thanos both decouple storage from individual Prometheus instances, enabling scalable multi-tenant long-term retention and unified querying across many Prometheus servers.

Question 4

When configuring the match[] parameter on the /federate endpoint, which selector would correctly fetch all metrics from the 'node' job?

Accepted Answer

{job="node"}

Answer

The match[] parameter accepts standard PromQL instant vector selectors using curly-brace syntax, so {job="node"} is the correct form to select all series for the node job.

Question 5

What are 'exemplars' in Prometheus and how do they relate to remote storage?

Accepted Answer

Trace ID references attached to metric observations that can be forwarded via remote_write

Answer

Exemplars are optional references to distributed trace IDs stored alongside histogram or summary observations; they can be forwarded through remote_write to link metrics with traces in a compatible backend.

(PCA) Prometheus Certified Associate Practice Test

(PCA) Prometheus Certified Associate Practice Test

PCA PCA Federation & Remote Storage 3