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

Distributing alert rule evaluation across multiple Prometheus servers

Answer

Synchronizing recording rules between primary and replica Prometheus instances

Answer

Load-balancing incoming metric push requests across a Prometheus cluster

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

Rewrite alert expression syntax before forwarding to Alertmanager

Answer

Dynamically rename the remote_write URL based on metric labels

Answer

Inject authentication headers into outbound remote write HTTP requests

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

They support additional metric types not available in standard Prometheus

Answer

They eliminate the need for any exporters by using agent-based metric push

Answer

They automatically generate Grafana dashboards from ingested metric names

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

{job~="node"}

Answer

job="node"

Answer

match(job, "node")

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

Special metric types used to track 99th-percentile latency without histograms

Answer

Pre-computed aggregation values stored alongside raw histograms

Answer

Configuration examples embedded in the prometheus.yml for documentation

Question 6

What is the purpose of a 'stale marker' sent by Prometheus via remote_write?

Accepted Answer

Signaling to the remote storage backend that a time series has stopped being scraped

Answer

Marking metric series that have exceeded the local retention period for cleanup

Answer

Flagging series that have inconsistent or unexpected label set changes

Answer

Indicating that the remote_write send queue has reached its capacity limit

Question 7

In a Prometheus remote_write configuration, what does the 'url' field specify?

Accepted Answer

The HTTP endpoint of the remote storage system that will receive the written metric samples

Answer

The scrape URL of the target exporter to monitor

Answer

The Alertmanager endpoint where firing alerts should be sent

Answer

The federation endpoint of another Prometheus server to pull metrics from