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(kuberay-rayservice-quickstart)=
# RayService Quickstart
## Prerequisites
This guide mainly focuses on the behavior of KubeRay v1.6.0 and Ray 2.46.0.
## What's a RayService?
A RayService manages these components:
* **RayCluster**: Manages resources in a Kubernetes cluster.
* **Ray Serve Applications**: Manages users' applications.
## What does the RayService provide?
* **Kubernetes-native support for Ray clusters and Ray Serve applications:** After using a Kubernetes configuration to define a Ray cluster and its Ray Serve applications, you can use `kubectl` to create the cluster and its applications.
* **In-place updating for Ray Serve applications:** See [RayService](kuberay-rayservice) for more details.
* **Zero downtime upgrading for Ray clusters:** See [RayService](kuberay-rayservice) for more details.
* **High-availabilable services:** See [RayService high availability](kuberay-rayservice-ha) for more details.
## Example: Serve two simple Ray Serve applications using RayService
## Step 1: Create a Kubernetes cluster with Kind
```sh
kind create cluster --image=kindest/node:v1.26.0
```
## Step 2: Install the KubeRay operator
Follow [this document](kuberay-operator-deploy) to install the latest stable KubeRay operator from the Helm repository. Note that the YAML file in this example uses `serveConfigV2` to specify a multi-application Serve configuration, available starting from KubeRay v0.6.0.
## Step 3: Install a RayService
```sh
kubectl apply -f https://raw.githubusercontent.com/ray-project/kuberay/v1.6.0/ray-operator/config/samples/ray-service.sample.yaml
```
## Step 4: Verify the Kubernetes cluster status
```sh
# Step 4.1: List all RayService custom resources in the `default` namespace.
kubectl get rayservice
# [Example output]
# NAME SERVICE STATUS NUM SERVE ENDPOINTS
# rayservice-sample Running 2
# Step 4.2: List all RayCluster custom resources in the `default` namespace.
kubectl get raycluster
# [Example output]
# NAME DESIRED WORKERS AVAILABLE WORKERS CPUS MEMORY GPUS STATUS AGE
# rayservice-sample-cxm7t 1 1 2500m 4Gi 0 ready 79s
# Step 4.3: List all Ray Pods in the `default` namespace.
kubectl get pods -l=ray.io/is-ray-node=yes
# [Example output]
# NAME READY STATUS RESTARTS AGE
# rayservice-sample-cxm7t-head 1/1 Running 0 3m5s
# rayservice-sample-cxm7t-small-group-worker-8hrgg 1/1 Running 0 3m5s
# Step 4.4: Check the `Ready` condition of the RayService.
# The RayService is ready to serve requests when the condition is `True`.
kubectl describe rayservices.ray.io rayservice-sample
# [Example output]
# Conditions:
# Last Transition Time: 2025-06-26T13:23:06Z
# Message: Number of serve endpoints is greater than 0
# Observed Generation: 1
# Reason: NonZeroServeEndpoints
# Status: True
# Type: Ready
# Step 4.5: List services in the `default` namespace.
kubectl get services
# NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
# ...
# rayservice-sample-cxm7t-head-svc ClusterIP None <none> 10001/TCP,8265/TCP,6379/TCP,8080/TCP,8000/TCP 71m
# rayservice-sample-head-svc ClusterIP None <none> 10001/TCP,8265/TCP,6379/TCP,8080/TCP,8000/TCP 70m
# rayservice-sample-serve-svc ClusterIP 10.96.125.107 <none> 8000/TCP 70m
```
When the Ray Serve applications are healthy and ready, KubeRay creates a head service and a Ray Serve service for the RayService custom resource. For example, `rayservice-sample-head-svc` and `rayservice-sample-serve-svc` in Step 4.5.
> **What do these services do?**
- **`rayservice-sample-head-svc`**
This service points to the **head pod** of the active RayCluster and is typically used to view the **Ray Dashboard** (port `8265`).
- **`rayservice-sample-serve-svc`**
This service exposes the **HTTP interface** of Ray Serve, typically on port `8000`.
Use this service to send HTTP requests to your deployed Serve applications (e.g., REST API, ML inference, etc.).
## Step 5: Verify the status of the Serve applications
```sh
# (1) Forward the dashboard port to localhost.
# (2) Check the Serve page in the Ray dashboard at http://localhost:8265/#/serve.
kubectl port-forward svc/rayservice-sample-head-svc 8265:8265
```
* Refer to [rayservice-troubleshooting.md](kuberay-raysvc-troubleshoot) for more details on RayService observability. Below is a screenshot example of the Serve page in the Ray dashboard. ![Ray Serve Dashboard](../images/dashboard_serve.png)
## Step 6: Send requests to the Serve applications by the Kubernetes serve service
```sh
# Step 6.1: Run a curl Pod.
# If you already have a curl Pod, you can use `kubectl exec -it <curl-pod> -- sh` to access the Pod.
kubectl run curl --image=curlimages/curl:latest -i --tty -- sh
# Step 6.2: Send a request to the fruit stand app.
curl -X POST -H 'Content-Type: application/json' rayservice-sample-serve-svc:8000/fruit/ -d '["MANGO", 2]'
# [Expected output]: 6
# Step 6.3: Send a request to the calculator app.
curl -X POST -H 'Content-Type: application/json' rayservice-sample-serve-svc:8000/calc/ -d '["MUL", 3]'
# [Expected output]: "15 pizzas please!"
```
## Step 7: Clean up the Kubernetes cluster
```sh
# Delete the RayService.
kubectl delete -f https://raw.githubusercontent.com/ray-project/kuberay/v1.6.0/ray-operator/config/samples/ray-service.sample.yaml
# Uninstall the KubeRay operator.
helm uninstall kuberay-operator
# Delete the curl Pod.
kubectl delete pod curl
```
## Next steps
* See [RayService](kuberay-rayservice) document for the full list of RayService features, including in-place update, zero downtime upgrade, and high-availability.
* See [RayService troubleshooting guide](kuberay-raysvc-troubleshoot) if you encounter any issues.
* See [Examples](kuberay-examples) for more RayService examples. The [MobileNet example](kuberay-mobilenet-rayservice-example) is a good example to start with because it doesn't require GPUs and is easy to run on a local machine.