whentimeslows/website
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add upgrade notes to cpu-mgt-policies

Browse Source 
Signed-off-by: Mac Chaffee <machaffe@renci.org>
This commit is contained in:
Mac Chaffee
2022-02-13 18:18:14 -05:00
parent 2853547cf9
commit d657a0d10a
1 changed files with 23 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
content/en/docs/tasks/administer-cluster/cpu-management-policies.md
+23 -1
View File
@@ -46,7 +46,8 @@ management policies to determine some placement preferences on the node.
### Configuration ### Configuration
The CPU Manager policy is set with the `--cpu-manager-policy` kubelet The CPU Manager policy is set with the `--cpu-manager-policy` kubelet
option. There are two supported policies: flag or the `cpuManagerPolicy` field in [KubeletConfiguration](/docs/reference/config-api/kubelet-config.v1beta1/).
There are two supported policies:
* [`none`](#none-policy): the default policy. * [`none`](#none-policy): the default policy.
* [`static`](#static-policy): allows pods with certain resource characteristics to be * [`static`](#static-policy): allows pods with certain resource characteristics to be
@@ -68,6 +69,27 @@ and `CPUManagerPolicyBetaOptions` feature gates. Diverging from the Kubernetes s
feature gates guard groups of options, because it would have been too cumbersome to add a feature feature gates guard groups of options, because it would have been too cumbersome to add a feature
gate for each individual option. gate for each individual option.
### Changing the CPU Manager Policy
Since the CPU manger policy can only be applied when kubelet spawns new pods, simply changing from
"none" to "static" won't apply to existing pods. So in order to properly change the CPU manager
policy on a node, perform the following steps:
1. [Drain](/docs/tasks/administer-cluster/safely-drain-node) the node.
2. Stop kubelet.
3. Remove the old CPU manager state file. The path to this file is
`/var/lib/kubelet/cpu_manager_state` by default. This clears the state maintained by the
CPUManager so that the cpu-sets set up by the new policy won’t conflict with it.
4. Edit the kubelet configuration to change the CPU manager policy to the desired value.
5. Start kubelet.
Repeat this process for every node that needs its CPU manager policy changed. Skipping this
process will result in kubelet crashlooping with the following error:
```
could not restore state from checkpoint: configured policy "static" differs from state checkpoint policy "none", please drain this node and delete the CPU manager checkpoint file "/var/lib/kubelet/cpu_manager_state" before restarting Kubelet
```
### None policy ### None policy
The `none` policy explicitly enables the existing default CPU The `none` policy explicitly enables the existing default CPU