PodChaos Experiment

This document introduces how to create PodChaos experiments.

Note:

Currently, Chaos Mesh does not support simulation injection of naked pods. And it only supports some specific pods, such as deployment, statefulset, daemonset.

PodChaos allows you to simulate pod faults, specifically pod failure and pod kill. pod failure can be used to simulate a situation where a pod is down. In this case, the pod is unavailable for a long time.

• Pod Failure action periodically injects errors to pods. And it will cause pod creation failure for a while. In other words, the selected pod will be unavailable in a specified period.

• Pod Kill action kills the specified pod (ReplicaSet or something similar might be needed to ensure the pod will be restarted).

pod-failure configuration file

Below is a sample pod-failure configuration file:

apiVersion: chaos-mesh.org/v1alpha1
kind: PodChaos
metadata:
  name: pod-failure-example
  namespace: chaos-testing
spec:
  action: pod-failure
  mode: one
  value: ''
  duration: '30s'
  selector:
    labelSelectors:
      'app.kubernetes.io/component': 'tikv'
  scheduler:
    cron: '@every 2m'

For more sample files, see examples. You can edit them as needed.

Description:

• action defines the specific chaos action for the pod. In this case, it is pod failure.
• mode defines the mode to run chaos action. Supported mode: one / all / fixed / fixed-percent / random-max-percent.
• value depends on the value of mode. If mode is one or all, leave value empty. If fixed, provide an integer of pods to do chaos action. If fixed-percent, provide a number from 0 to 100 to specify the percent of pods the server can do chaos action. If random-max-percent, provide a number from 0 to 100 to specify the max percent of pods to do chaos action.
• duration defines the duration for each chaos experiment. The value of the duration field is 30s, which indicates that pod failure will last 30 seconds.
• selector is used to select pods that are used to inject chaos actions. For more details, see Define the Scope of Chaos Experiment.
• scheduler defines the scheduler rules for the running time of the chaos experiment. For more rule information, see robfig/cron.

pod-kill configuration file

Below is a sample pod-kill configuration file:

apiVersion: chaos-mesh.org/v1alpha1
kind: PodChaos
metadata:
  name: pod-kill-example
  namespace: chaos-testing
spec:
  action: pod-kill
  mode: one
  selector:
    namespaces:
      - tidb-cluster-demo
    labelSelectors:
      'app.kubernetes.io/component': 'tikv'
  scheduler:
    cron: '@every 1m'

The detailed description of each field in the configuration template are consistent with that in pod-failure.