Add Runbook

Adding new runbook #

How? #

  1. Figure out alert category from the alert name
  2. Open a PR with new file placed in correct component subdirectory. You can use links below to open a PR directly
  3. Name the new file the same as the alert it describes
  4. Fill in the new file following a template below.
  5. Remember to put alert name at the top of the file

Finding correct component #

All alerts are prefixed with a name of the component. If the alert is not prefixed, it should go into “general” component category.

For example KubeStateMetricsListErrors suggest it is a kube-state-metrics alert, but Watchdog is a “general” one.

Template #

Runbook example based on a NodeFilesystemSpaceFillingUp (thanks to @beorn7):

# NodeFilesystemSpaceFillingUp

## Meaning

This alert is based on an extrapolation of the space used in a file system. It fires if both the current usage is above a certain threshold _and_ the extrapolation predicts to run out of space in a certain time. This is a warning-level alert if that time is less than 24h. It's a critical alert if that time is less than 4h.

## Impact

A filesystem running completely full is obviously very bad for any process in need to write to the filesystem. But even before a filesystem runs completely full, performance is usually degrading.

## Diagnosis

Study the recent trends of filesystem usage on a dashboard. Sometimes a periodic pattern of writing and cleaning up can trick the linear prediction into a false alert.

Use the usual OS tools to investigate what directories are the worst and/or recent offenders.

Is this some irregular condition, e.g. a process fails to clean up behind itself, or is this organic growth?

## Mitigation

<Insert site specific measures, for example to grow a persistent volume.>