0
374
ViewsAvoiding AWS EKS IPs limitation per node
A company would like to scale their microservice application using namespaces, namespace represents a separate application per each client. The application consists of 22 microservices, the company has 80 clients, hence there will be 22 * 80 = 1760 pods in the cluster. The diagram is given below.
It was initially calculated that it would be enough to have 4 r4.xlarge nodes to keep proper performance. But the company has encountered a different kind of problem: the number of IP addresses per instance. For example, for 4 nodes of r4.xlarge type only: 4(nodes) * 4(network interfaces) * 15(Private IPv4 addresses) = 240 addresses available, but 1760 needed!
Increasing the number of nodes several times over budget.
Are there any ways to avoid that IPs amount limitation? Or maybe you can propose another solution
2 answers
Answer question0
Limitation is because you are using AWS VPC CN Plugin docs.aws.amazon.com/eks/latest/userguide/pod-networking.html. Using this plugin allows Kubernetes pods to have the same IP address inside the pod as they do on the VPC network.
As per Documentation, The Amazon VPC CNI plugin might not meet requirements for all use cases. Amazon EKS maintains a network of partners that offer alternative CNI solutions with commercial support options. For more information, see Alternate compatible CNI plugins. https://docs.aws.amazon.com/eks/latest/userguide/alternate-cni-plugins.html
Please note that you cannot use IP address targeting mode of AWS Load Balancer Controller. It will have to be Instance Targeting Mode.