Kubernetes Namespace Resource Quota and Limits

Kubernetes, an open-source container orchestration platform, empowers organizations to deploy, scale, and manage containerized applications efficiently. As Kubernetes environments grow, managing resources becomes crucial to ensure optimal performance and resource utilization. One powerful feature Kubernetes offers for this purpose is the Namespace Resource Quota and Limits.

Understanding Namespace Resource Quota:

In Kubernetes, a namespace provides a way to logically divide cluster resources among multiple users or projects. Resource quotas allow administrators to set constraints on the amount of resources a namespace can consume. This prevents resource hogging and ensures fair distribution among different workloads.

Setting Resource Quota:

To set a resource quota for a namespace, use the following command:

kubectl create quota <quota-name> --hard=<resource1>=<value1>,<resource2>=<value2> --namespace=<namespace-name>

Replace <quota-name>, <resource1>, <value1>, <resource2>, <value2>, and <namespace-name> with appropriate values.

Setting Resource Limits:

Resource limits define the maximum amount of resources a container or pod can consume. This prevents a single pod from monopolizing cluster resources and affecting others adversely.

Defining Resource Limits in Pod Specification:

To set resource limits for a pod, include the following in the pod specification:

resources:
  limits:
    <resource1>: <limit1>
    <resource2>: <limit2>

Replace <resource1>, <limit1>, <resource2>, and <limit2> with the desired values.

Step-by-Step Instructions:

1. Creating a Namespace:

If you don't have a namespace yet, create one using:

kubectl create namespace <namespace-name>

Replace <namespace-name> with your desired namespace name.

2. Setting Resource Quota:

Create a resource quota for the namespace using:

kubectl create quota <quota-name> --hard=<resource1>=<value1>,<resource2>=<value2> --namespace=<namespace-name>

3. Applying Resource Limits:

In your pod specification, define resource limits:

resources:
  limits:
    <resource1>: <limit1>
    <resource2>: <limit2>

More Examples:

Example 1: Resource Quota for CPU and Memory:

kubectl create quota cpu-mem-quota --hard=cpu=2,memory=2Gi --namespace=my-namespace

Example 2: Pod with Resource Limits:

apiVersion: v1
kind: Pod
metadata:
  name: mypod
  namespace: my-namespace
spec:
  containers:
  - name: mycontainer
    image: myimage
    resources:
      limits:
        cpu: "1"
        memory: "1Gi"