Revision garbage collection¶

The config-gc ConfigMap contains settings that determine in-active revisions are cleaned up. This ConfigMap is located in the knative-serving namespace.

Cluster-wide configuration¶

The following properties allow you to configure revision garbage collection:

Name	Description
`retain-since-create-time`	Duration since creation before considering a revision for GC or "disabled"
`retain-since-last-active-time`	Duration since active before considering a revision for GC or "disabled"
`min-non-active-revisions`	Minimum number of non-active revisions to retain.
`max-non-active-revisions`	Maximum number of non-active revisions to retain or "disabled" to disable any maximum limit.

Revisions are retained if they belong to any one of the following categories:

Is active and is being reference by a route
Created within retain-since-create-time
Last referenced by a route within retain-since-last-active-time
There are fewer than min-non-active-revisions

Examples¶

Immediately collect any inactive revision¶

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-gc
  namespace: knative-serving
data:
  min-non-active-revisions: "0"
  max-non-active-revisions: "0"
  retain-since-create-time: "disabled"
  retain-since-last-active-time: "disabled"

Keep around the last ten non-active revisions¶

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-gc
  namespace: knative-serving
data:
  retain-since-create-time: "disabled"
  retain-since-last-active-time: "disabled"
  max-non-active-revisions: "10"

Disable garbage collection¶

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-gc
  namespace: knative-serving
data:
  retain-since-create-time: "disabled"
  retain-since-last-active-time: "disabled"
  max-non-active-revisions: "disabled"

Complex example¶

The following example configuration keeps recently deployed or active revisions, always maintains the last two revisions in case of rollback, and prevents burst activity from exploding the count of old revisions:

apiVersion: v1
kind: ConfigMap
metadata:
  name: config-gc
  namespace: knative-serving
data:
  retain-since-create-time: "48h"
  retain-since-last-active-time: "15h"
  min-non-active-revisions: "2"
  max-non-active-revisions: "1000"

Per-revision options¶

You can configure a revision so that it is never garbage collected by adding the serving.knative.dev/no-gc: "true" annotation:

apiVersion: serving.knative.dev/v1
kind: Revision
metadata:
  annotations:
    serving.knative.dev/no-gc: "true"
spec:
...