What is the purpose of resource requests in Kubernetes?

The purpose of resource requests in Kubernetes is primarily to guide the kube-scheduler in determining the optimal node for placing Pods. When you specify resource requests for a container, you indicate the minimum amount of CPU and memory resources that a container requires to run efficiently. This information is crucial for the kube-scheduler, as it uses these requests to find a suitable node that has enough available resources to meet the specified requirements.

By evaluating the resource requests, the kube-scheduler can make informed decisions about where to place the Pods, ensuring that they do not end up on nodes that are already overcommitted or unable to provide the necessary resources. This enhances overall cluster efficiency and can improve application performance by avoiding resource contention among Pods.

While resource requests may indirectly impact performance, they are not designed to limit performance directly, nor do they solely define memory usage or function as a monitoring tool. Instead, requests are about guaranteeing minimum resources and optimizing scheduling decisions within the Kubernetes cluster.