AWS EKS maximum number of Pods per EC2 Node instance limit.

Managing Kubernetes workloads on AWS EKS (Elastic Kubernetes Service) involves optimizing resources, one of which is the number of Pods each EC2 instance can support. Every managed Kubernetes service, including AWS EKS, has operational limitations tied to the maximum Pods per node based on the EC2 instance type. Understanding and calculating these limits can help prevent resource allocation issues and streamline your deployments.

Why is There a Pod Limit Per Node in AWS EKS?

The maximum number of Pods a node can handle depends on the networking resources of the EC2 instance:

• Each EC2 instance has a certain number of Elastic Network Interfaces (ENIs) and IPv4 addresses per ENI.
• Not every IP address on an ENI can be used for Pods. AWS reserves some IPs for essential services, such as the AWS CNI and kube-proxy.

For instance:

• A t3.medium instance has a max of 17 Pods.
• A t3.large can support 35 Pods.

Formula to Calculate Max Pods Per EC2 Instance

Using the following formula, you can estimate the maximum number of Pods an instance type supports:

Max Pods=(Number of ENIs×IPv4 per ENI)−1

Example with a t2.medium EC2 instance

For a t2.medium instance, here are the relevant details:

• Number of ENIs: 3
• IPv4 per ENI: 6

Using these values in the formula:

Max Pods=(3×6)−1

Max Pods=18−1

Max Pods=17

So, a t2.medium instance in EKS can support up to 17 pods.

Applying this formula manually can be tedious, especially if you manage multiple instance types or scale dynamically.

Max Pods Calculator

To simplify this process, you can use an online Max Pods per Node Calculator. This tool automatically calculates the maximum pods based on instance type, making scaling and management much easier. You can access it here: Kubernetes Max Pods per Node Calculator.

Using this calculator can save time and reduce errors, especially for complex deployments.

The Max Pods Calculator lets you:

• Calculate Pods per EC2 instance based on the latest ENI and IPv4 limits.
• Select any instance type to see its capacity, allowing you to make informed scaling decisions.
• Avoid manual math every time you adjust your instance sizes in EKS.

Cheers to a smoother EKS experience! 🎉

💬 If you have any suggestions or questions, please leave a comment below!
👏 If you found this article helpful, feel free to give it a clap and share it with your friends.

Feel free to connect, and let’s continue the conversation!😊

• YouTube: Techwithpatil
• LinkedIn: Tech with Patil
• Instagram: techwithpatil

Thank you! 🙏

Get notified so you don't miss out on techwithpatil's latest posts! 👇