Parallel drain in Cluster Autoscaler

[x13n]

Which component are you using?:

cluster-autoscaler

Is your feature request designed to solve a problem? If so describe the problem this feature should solve.:

Scale down of non-empty nodes taking very long time in large clusters.

Describe the solution you'd like.:

Parallel drain

Describe any alternative solutions you've considered.:

None really, the main factor contributing to slow scale down is the time to drain nodes one by one.

Additional context.:

Design was added in #4766

/assign

[k8s-triage-robot]

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/lifecycle stale

[x13n]

/remove-lifecycle stale

There are a few more changes that need adding, but hopefully initial implementation will land before 1.26 is cut.

[x13n]

The new behavior can be enabled with --parallel-drain=true, thanks to #5353. This is experimental as of now, so disabled by default.

[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle stale
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

[x13n]

/remove-lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle stale
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

[x13n]

/remove-lifecycle stale

I need to change the flag to be enabled by default now.