Prometheus is a Cloud Native Computing Foundation (CNCF) graduated project specifically designed for monitoring and alerting in dynamic, microservices-based environments like Kubernetes. It operates on a pull-based model, actively scraping (collecting) time-series metrics from configured endpoints. Its powerful query language (PromQL) and integration with the Kubernetes service discovery mechanism make it the de facto standard for collecting and monitoring metrics within the cloud native ecosystem. It serves as the core data source for metrics-based observability.

A. Grafana is a visualization and analytics tool. It queries and displays data from sources like Prometheus but does not collect the metrics itself.

B. ELK Stack (Elasticsearch, Logstash, Kibana) is a solution primarily focused on collecting, storing, and analyzing log data, not time-series metrics.

C. OpenTelemetry is an instrumentation framework used to generate and export telemetry data (metrics, logs, traces), but it is not the backend system that stores and monitors the metrics.

1. Prometheus Documentation: "Prometheus is an open-source systems monitoring and alerting toolkit... It collects metrics from configured targets at given intervals

evaluates rule expressions

displays the results

and can trigger alerts if some condition is observed to be true."

Source: Prometheus Authors

Prometheus Documentation

"Overview"

Section 1. Retrieved from https://prometheus.io/docs/introduction/overview/

2. Kubernetes Documentation: "The CNCF's Prometheus project can natively monitor Kubernetes

nodes

and Prometheus... Prometheus is the most common monitoring tool used with Kubernetes by the community."

Source: Kubernetes Authors

Kubernetes Documentation

"Tools for Monitoring Resources"

Section: "Full metrics solutions". Retrieved from https://kubernetes.io/docs/tasks/debug/debug-cluster/resource-metrics-pipeline/

3. Cloud Native Computing Foundation (CNCF): The CNCF

which hosts Kubernetes

lists Prometheus as a "Graduated" project

signifying its maturity and widespread adoption for monitoring.

Source: CNCF

Prometheus Project Journey. Retrieved from https://www.cncf.io/projects/prometheus/

4. University Courseware: Course materials on cloud computing frequently cite Prometheus as the standard for metrics collection in Kubernetes.

Source: University of California

Berkeley

CS 162: Operating Systems and System Programming

Lecture 22: "Cloud Computing"

Slide 53

"Monitoring: Prometheus". Retrieved from https://inst.eecs.berkeley.edu/~cs162/fa20/static/lectures/22-Cloud.pdf