Increasing Node Allocatable Memory on an EKS Node

Asked Jan 23 '22 at 14:45

Active Jan 23 '22 at 14:45

Viewed 968 times

Occasionally my EKS nodes become NotReady and freeze-up due to high page swapping. This occurs despite the fact that swapping is disabled, likely due to the explanation here on why swapping can't actually be disabled on Linux.

To remediate this, I'd like to increase the amount of memory that is reserved by the node (and unavailable for pods). I have observed issues with swapping only above 95% memory utilization, so by restricting the node to 90% usage I should be able to prevent swapping induced by memory pressure.

What is the correct way on EKS to customize Node Allocatable for a managed node group?
Do I need to create a new node group or can I update an existing one?
Must the node group be created with eksctl or can I customize a node group created in the AWS web console too?

asked Jan 23 '22 at 14:45

Natan Yellin

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Did you see pods been evicted when your node is under pressure? – gohm'c Jan 23 '22 at 15:24
@gohm'c no, I don't – Natan Yellin Jan 23 '22 at 17:26
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You should see pods been evicted first. Do you currently use self-managed node group with custom image? – gohm'c Jan 24 '22 at 03:28
No, it's all AWS managed node groups. – Natan Yellin Jan 24 '22 at 09:10
There are pods without memory limits though. (I know this is a problem, but it's not entirely under my control.) – Natan Yellin Jan 24 '22 at 09:11
Which Kubernetes version are you using? When node is `NotReady`, could you please run `kubectl describe node {node-name}` and check `Events:` (at the bottom of the command output) and paste it here? – Mikolaj S. Jan 24 '22 at 13:47
@WytrzymałyWiktor no, afraid not. We've added memory limits and it hasn't occured since, but I'd still like to customize Node Allocatable – Natan Yellin Jan 26 '22 at 16:53
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Could you answer my questions - which Kubernetes version are you using? When node is NotReady, could you please run `kubectl describe node {node-name}` and check `Events` (at the bottom of the command output) and paste it here? – Mikolaj S. Jan 28 '22 at 11:59
@MikolajS. yes, will check and follow up later this week – Natan Yellin Jan 29 '22 at 16:17

Increasing Node Allocatable Memory on an EKS Node

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