Feature Overview (aka. Goal Summary)  

Ability to scale the amount of worker nodes in a Hosted Cluster in ARO/HCP to 500 nodes.

Goals (aka. expected user outcomes)

• Customers will be able to have their managed Hosted Control Planes scale up to 500 concurrent worker nodes without control plane degradation

Requirements (aka. Acceptance Criteria):

• HCP AKS topology does not use request serving nodes
• It is possible to scale down and up 1..500 nodes
• There's no downtime or API availability loss during scale up.

Anyone reviewing this Feature needs to know which deployment configurations that the Feature will apply to (or not) once it's been completed.  Describe specific needs (or indicate N/A) for each of the following deployment scenarios. For specific configurations that are out-of-scope for a given release, ensure you provide the OCPSTRAT (for the future to be supported configuration) as well.

Use Cases (Optional):

Customer workloads require up to 500 nodes in a single hosted cluster.

Background

OCPSTRAT-1251 saw a big amount of work to enable customers to reach 500 nodes in the special ROSA/HCP topology.

Customer Considerations

500 nodes is the sum of all the maximum machines for the combined machinepools of an ARO/HCP hosted cluster

Documentation Considerations

There should be documentation/SOPs for spotting and reacting to possible noisy neighbor patterns.

Interoperability Considerations

ARO/HCP