# Show load balancing

> Run several hello-kubernetes pods across your nodes, and watch a Service send requests to each of them.

Each page shows the pod and the node that answered. With several pods, you can watch a Service spread requests across them. This guide installs four pods, sees where they run, and sends requests to them from inside the cluster.

You need `kubectl`, [Helm 4](https://helm.sh/docs/intro/install/), and a cluster. With more than one node, the pods spread across them.

## Install four pods

```bash
helm install spread oci://ghcr.io/paulbouwer/charts/hello-kubernetes \
  --namespace hello-lb --create-namespace \
  --set deployment.replicaCount=4 \
  --set service.type=ClusterIP \
  --wait
kubectl get pods --namespace hello-lb --output wide
```

The `NODE` column shows where each pod runs. The scheduler spreads them across nodes where it can.

## Send requests through the Service

Run a short-lived pod that asks the Service for the page 10 times, and prints the pod that answered each time:

```bash
kubectl run lb-test --namespace hello-lb --rm -i --quiet --restart=Never --image=busybox:1.37 -- \
  sh -c 'for i in $(seq 1 10); do wget -qO- http://hello-kubernetes-spread | grep -A1 "pod:" | tail -n1; done'
```

*Output:*

```text
      <td>hello-kubernetes-spread-7798544b7b-fvsmz</td>
      <td>hello-kubernetes-spread-7798544b7b-s9bfh</td>
      <td>hello-kubernetes-spread-7798544b7b-fvsmz</td>
      <td>hello-kubernetes-spread-7798544b7b-lqzrb</td>
      ...
```

Each request opens a new connection, and the Service sends each connection to one of the pods.

## In a browser

Reach the app through a `LoadBalancer` Service, an [Ingress](https://paulbouwer.github.io/hello-kubernetes/docs/deploy/ingress.md) or a [Gateway](https://paulbouwer.github.io/hello-kubernetes/docs/deploy/gateway.md), and refresh the page. The pod name changes, but not on every refresh. A browser keeps its connection open, and the Service balances connections, not requests. An Ingress controller or a Gateway balances each request, so the change is easier to see through one.

`kubectl port-forward` always connects to one pod, so the name never changes through it.

## Clean up

```bash
helm uninstall spread --namespace hello-lb
kubectl delete namespace hello-lb
```