scheduling-framework.md: update Reserve and Unreserve descriptions #22035
Conversation
Add warning to avoid sharing security groups between multiple services in the `service.beta.kubernetes.io/aws-load-balancer-security-groups` annotation
Signed-off-by: Weiping Cai <weiping.cai@daocloud.io>
…s/docs/concepts_workloads_controllers/jobs-run_and_replicaset
Some words in spanish weren't translated correctly.
--dry-run is deprecated `--restart=Never` flag is unnecessary to create a pod from 1.18
imagePullPolicy when defined without a value defaults to Always not to IfNotPresent
Update docs for new container- Makefile targets
update to right styling for VolumeSnapshotClass concept
k8s-ci-robot
added
the
sig/docs
|
Deploy preview for kubernetes-io-master-staging ready! Built with commit 81b50a6 https://deploy-preview-22035--kubernetes-io-master-staging.netlify.app |
|
|
||
| The reserve extension point happens before the scheduler actually binds a Pod to | ||
| a node and its uses are three-fold. First, it serves as a hook to allocate | ||
| resources in the designated node that the scheduled Pod might need. Second, it |
There was a problem hiding this comment.
It shouldn't be used to allocate resources. Such actions are usually costly and should be done in PreBind.
There was a problem hiding this comment.
We should also preserve the phrasing "Plugins which maintain runtime state (aka "stateful plugins") should use this extension point"
There was a problem hiding this comment.
Is the volume binding plugin an exception then? I'm now confused as to whether reserve plugins are purely informational or if they can have side effects other than cycle state changes.
There was a problem hiding this comment.
Volume binding plugin only updates its cache. It doesn't bind the volumes. That's done in PreBind.
| serves as an informational plugin which maintain runtime state (aka "stateful | ||
| plugins") to be notified by the scheduler when resources on a node are being | ||
| reserved for a given Pod. Third, it exists to prevent race conditions while the | ||
| scheduler waits for the bind to succeed. This is the penultimate step in the |
There was a problem hiding this comment.
Why do you say penultimate?
There was a problem hiding this comment.
There's also a permit extension point in the scheduling cycle -- reserve is not the last step.
There was a problem hiding this comment.
Or is permit a part of the binding cycle? The flow chart in this doc says it's a part of the scheduling cycle, but your other comment says it's a part of the binding cycle.
There was a problem hiding this comment.
Oh, I forgot about kubernetes/kubernetes#88199. Please make sure the doc for Permit is up to date. I believe we did update it.
|
|
||
| The reserve extension point may fail or succeed. If it fails, the | ||
| [Unreserve](#unreserve) extension point is triggered. Alternatively, if it | ||
| succeeds, the Pod is deemed to be in the reserved state, at which point, |
There was a problem hiding this comment.
We are actually packing information pertaining to the other extension points here.
It should be more like:
"If it succeeds, the binding routine is initiated, where Permit is the first extension point to run."
|
Hi @adtac It looks to me as if you wanted to target docs for the next release? If that's right, you should revise this pull request and choose dev-1.19 as the target branch. /hold |
|
Oops, missed that. Yes, this should target dev-1.19 |
|
/milestone 1.19 |
k8s-ci-robot
added
size/XXL
|
Deploy preview for kubernetes-io-vnext-staging processing. Building with commit cbdd710 https://app.netlify.com/sites/kubernetes-io-vnext-staging/deploys/5ef3a2913ef4cf000877947c |
k8s-ci-robot
added
language/es
|
[APPROVALNOTIFIER] This PR is NOT APPROVED This pull-request has been approved by: The full list of commands accepted by this bot can be found here.
Needs approval from an approver in each of these files:
Approvers can indicate their approval by writing |
k8s-ci-robot
added
language/it
|
welp, github just autoclosed the PR :( I'll create a new one with the correct target branch I guess |
|
/reopen |
|
@alculquicondor: Failed to re-open PR: state cannot be changed. The adtac/reserve branch has been deleted. In response to this:
Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. |
This doc update depends on the following API changes:
tl;dr: Reserve and Unreserve plugins have been merged into one plugin called a Reserve plugin. These plugins must implement both extension points. Also, since reserve extension points may fail, after kubernetes/kubernetes#92391, we will trigger the unreserve extension point in the event of such failures. The extension points are no longer merely informational; they can have state changes + side effects such as allocating resources.
/assign @alculquicondor
/cc @ahg-g
/sig scheduling
/hold