[EKS] [request]: Add/Remove Availability Zone(AZ) for Worker Nodes during EKS Cluster Dataplane Upgrade

[jafferaws]

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Tell us about your request
Add/Remove Availability Zone(AZ) for Worker Nodes during EKS Cluster Dataplane Upgrade

Which service(s) is this request for?
EKS

Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?
The ability to expand the number of Availability Zones (AZ) for the Dataplane (Worker Nodes) Node Group while upgrading the Cluster. Clients seeking more IP capacity for worker nodes and high availability may wish to add or remove the extra AZ. We urgently need to have this feature available for customer needs as AWS EKS does not currently offer it.

Are you currently working around this issue?
We are unable to resolve this problem during Cluster upgrade scenarios.

[mikestef9]

Can you provide some more details here, don't really understand what the ask is

[jafferaws]

@mikestef9 Thank you for the comment.

Here's the ask:
Scenario: I have two Availability Zones (AZ) tied to my EKS cluster. In the course of upgrading the EKS version from one version to newer version, I would like to add more AZ to the cluster. I want to convert it from a 2AZ cluster to a 3AZ cluster. I'm not aware of any AWS-provided solutions at this time for this use case.

Am looking for solution to add additional Availability Zone to a existing EKS clusters while performing EKS version Upgrade.

Kindly provide the solution. Any inputs would be highly appreciated.

Thanks,
Jaffer

[mikestef9]

Still don't follow. EKS already supports changing subnets associated with the cluster control plane. And you can always choose which subnets/AZs to run worker nodes at any time.

[jafferaws]

Hi @mikestef9 . My request is not about the control plane subnet changes. I need to add new Availability Zone(AZ) to the Data plane (worker node) in the existing EKS cluster. Meaning, I already have a data plane (worker nodes) with 2 Availability Zone setup. I want to add additional Availability Zone to the existing cluster. Is it possible? if not, I would need that option available as feature request.

[pedroperezclickit]

Hello @jafferaws any update from AWS about this topic?

[wooyoungAhn]

Hello
I have same problem
any update from AWS?

[AliceMajere]

Hello,
I would like this feature too. It is possible to expend the CIDR and add/remove subnet, but you cannot add a subnet from AZ3 if the EKS cluster was created with only AZ1 and AZ2 originally.
It would be great if we could expend/reduce the cluster number of AZ without having to create a complete new cluster.

[mikestef9]

There may be multiple asks here which is getting confusing. You cannot use a new AZ in the EKS control plane subnets. But the dataplane (worker nodes) you have always been able to run whereever you want. It's completed unrelated to the subnets passed to the control plane.

A feature request for updating control plane subnets to new AZs is now open #2330, but I still don't understand what this request is asking for.