Prometheus

Prometheus is an open-source monitoring and alerting toolkit originally built at SoundCloud. It is a part of the Cloud Native Computing Foundation and is widely used for monitoring Kubernetes and microservices architectures.

Prometheus works by scraping and storing metrics from configured targets at given intervals. It includes a local on-disk time series database to store metric data efficiently and reliably for long periods. Some key components and concepts in Prometheus include exporters, which expose metrics from services in a standard format for Prometheus to scrape; service discovery, which allows Prometheus to discover targets through mechanisms like Kubernetes; alerting rules, which allow you to define alert conditions and send notifications; and PromQL, a powerful query language to analyze and aggregate the metrics.

Prometheus is well-suited for Kubernetes monitoring because of its native support for service discovery and relabeling. For example, you can configure Prometheus to automatically discover all pods in a Kubernetes cluster labeled with the app=my-app label and start scraping metrics from them. It also integrates well with Grafana for building dashboards. Overall, Prometheus provides a flexible and robust platform for gathering metrics and alerting on issues in Kubernetes and microservices environments.