> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Scaling the Deployment using kubectl

> This tutorial explains how to scale an Azure Kubernetes Service deployment and understand the pod limit enforced by Azure CNI.

In this tutorial, you’ll learn how to scale an Azure Kubernetes Service (AKS) deployment and understand the per-node pod limit enforced by Azure CNI. We’ll cover:

1. Inspecting your current Deployment and Service
2. Scaling the Deployment to 5 replicas
3. Hitting the 30-pod per-node limit
4. Examining Namespaces and system pods

***

## 1. Inspect the current Deployment and Service

Before scaling, verify your application’s replica count and external endpoint.

```bash theme={null}
# Check the Deployment replicas
kubectl get deployments
# Output example:
# NAME            READY   UP-TO-DATE   AVAILABLE   AGE
# Find the LoadBalancer’s public IP
kubectl get service
# NAME            TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)         AGE
# kodekloudapp    LoadBalancer   10.0.199.121    20.247.251.108  80:30895/TCP    73m
# kubernetes      ClusterIP      10.0.0.1        <none>          443/TCP         124m
```

***

## 2. Scale to 5 replicas

Increase your Deployment to five pods:

```bash theme={null}
kubectl scale deployment kodekloudapp --replicas=5
kubectl get deployment kodekloudapp
# NAME            READY   UP-TO-DATE   AVAILABLE   AGE
# kodekloudapp    5/5     5            5           76m
```

### Validate load balancing

Open three incognito browser windows and navigate to your Service’s public IP. You should see traffic routed to different pods:

<Frame>
  ![The image shows three browser windows displaying the "KodeKloudApp" homepage with a welcome message, system name, and IP address highlighted in yellow. Each window has a different system name and IP address.](https://kodekloud.com/kk-media/image/upload/v1752869529/notes-assets/images/Azure-Kubernetes-Service-Scaling-the-Deployment-using-kubectl/kodekloudapp-homepage-browser-windows.jpg)
</Frame>

***

## 3. Scale to the pod limit (30 replicas)

When you created the AKS cluster, you configured Azure CNI with a maximum of 30 pods per node. Let’s push the Deployment to that limit:

```bash theme={null}
kubectl scale deployment kodekloudapp --replicas=30
kubectl get deployment kodekloudapp
# NAME            READY   UP-TO-DATE   AVAILABLE   AGE
# kodekloudapp    16/30   30           16          78m
```

Only 16 pods are running; the rest remain `Pending`:

```bash theme={null}
kubectl get pods
# NAME                           READY   STATUS    RESTARTS   AGE
# kodekloudapp-677fc758c5-5k92g  0/1     Pending   0          57s
# kodekloudapp-677fc758c5-bbp84  0/1     Pending   0          57s
# ...
```

### Filter non-running pods

List pods that aren’t in the `Running` phase:

```bash theme={null}
kubectl get pods --field-selector=status.phase!=Running
```

### Inspect pod scheduling events

Describe one pending pod to see why it isn’t scheduled:

```bash theme={null}
kubectl describe pod kodekloudapp-677fc758c5-5k92g
```

In the **Events** section you’ll find:

```text theme={null}
Warning  FailedScheduling   2m     default-scheduler   0/1 nodes are available: 1 Too many pods.
Normal   NotTriggerScaleUp  110s   cluster-autoscaler  max node group size reached
```

***

## 4. Namespaces and system pods

AKS uses several namespaces to isolate workloads. System pods in `kube-system` count toward your per-node limit.

```bash theme={null}
kubectl get namespaces
# NAME              STATUS   AGE
# default           Active   129m
# kube-node-lease   Active   129m
# kube-public       Active   129m
# kube-system       Active   129m
```

### Namespace overview

| Namespace       | Purpose                     | Pod Count |
| --------------- | --------------------------- | --------- |
| default         | User applications           | 16        |
| kube-node-lease | Node heartbeat leases       | 0         |
| kube-public     | Public config and resources | 0         |
| kube-system     | Core cluster services       | 12+       |

```bash theme={null}
kubectl get pods --namespace kube-system
# NAME                                               READY   STATUS    RESTARTS   AGE
# ama-logs-rs-7f8bcb7c6f-5dlqq                       1/1     Running   0          131m
# coredns-59b6bf8b4f-lwt4c                           1/1     Running   0          131m
# metrics-server-7d74d8758-wfsdd                     2/2     Running   0          130m
# ...
```

<Callout icon="triangle-alert" color="#FF6B6B">
  Azure CNI assigns IPs from your VNet based on the `--max-pods` setting at cluster creation. **You cannot change this limit post-creation**.
</Callout>

***

## Next steps

To work around the per-node pod limit, consider:

* Deploying multiple node pools with different `--max-pods` settings
* Switching to Kubenet or Azure CNI Overlay networks
* Splitting workloads across separate namespaces and node pools

***

## Links and References

* [Kubernetes Scaling Documentation](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#scaling-a-deployment)
* [AKS Networking Concepts](https://learn.microsoft.com/azure/aks/concepts-network)
* [Azure CNI IP Management](https://learn.microsoft.com/azure/aks/configure-azure-cni)

<CardGroup>
  <Card title="Watch Video" icon="video" cta="Learn more" href="https://learn.kodekloud.com/user/courses/azure-kubernetes-service/module/2e4891fe-2f53-4239-9ab9-8b15ba4c6369/lesson/9448e603-60d1-4b69-9175-3ae44984a0d8" />
</CardGroup>