@mercure/cgroupv2-metrics

npm utils module to read metrics in cgroup v2


Keywords
node, cgroup, metrics, docker, kubernetes, cgroups, cgroups-v2, k8s, linux-kernel, prestop, readiness-probe, typescript
License
MIT
Install
npm install @mercure/cgroupv2-metrics@0.0.1

Documentation

build status

CGROUP V2 METRICS

  • npm module for reading cgroupv2 RAM and CPU metrics.
  • Reads from /sys/fs/cgroup/.
  • Useful for kubernetes probes : readiness, liveness or prestop, all available since v1.25

Installation

npm install @mercure/cgroupv2-metrics

Use case

  • You can use those metrics to have more control over kubernetes pods :

A pod has a heavy load incoming, and you do not want that pod to be reached by kubernetes internal load-balancer. Since kubernetes does not provide load-balancer over resources consumption, you can use a readiness probe, which check metrics every "x" seconds and trigger the probe if RAM and/or CPU are overloaded. This probe will eject the pod from load-balancer by setting the pod "unavailable". Once consumption will decrease to an acceptable level, probe trigger will stop and the pod will be available from load-balancer again.

  • Check examples folder to see how k8s probes can be implemented

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