Monitoring

Monitoring is about collecting metrics from the infrastructure, as well as applications.

The long used and now deprecated Heapster has been replaced with an integrated Metrics Server. Once installed and configured, the server exposes a standard API which other agents can use to determine usage. It can also be configured to expose custom metrics, which then could also be used by autoscalers to determine if an action should take place.

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Prometheus is part of the Cloud Native Computing Foundation (CNCF). As a Kubernetes plugin, it allows you to scrape resource usage metrics from Kubernetes objects across the entire cluster. It also has several client libraries which allow you to instrument your application code in order to collect application-level metrics.

Other CNCF projects such as OpenTelemetry, which allows for adding instrumentation to code, and Jaeger, for consuming the telemetry, are popular to use when tracking distributed issues. An alpha feature is API Server Tracing, which leverages OpenTelemetry. More can be found on the Kubernetes website.