# Deploying a GreptimeDB Cluster with Frontend Groups

> Step-by-step guide to deploying a GreptimeDB cluster with frontend groups on Kubernetes, including prerequisites, configuration, installation, and verification.

# Deploying a GreptimeDB Cluster with Frontend Groups

In this guide, you will learn how to deploy a GreptimeDB cluster on Kubernetes with a frontend group consisting of multiple frontend instances.

## Prerequisites

- [Docker](https://docs.docker.com/get-started/get-docker/) >= v23.0.0
- [kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) >= v1.18.0
- [Helm](https://helm.sh/docs/intro/install/) >= v3.0.0
- [GreptimeDB Operator](https://github.com/GrepTimeTeam/greptimedb-operator) >= v0.3.0
- [ETCD](https://github.com/bitnami/charts/tree/main/bitnami/etcd)

## Upgrade operator

Install the GreptimeDB Operator, setting the image version to be greater than or equal to `v0.3.0`.
For detailed instructions on upgrading the operator, please refer to the [GreptimeDB Operator Management](/user-guide/deployments-administration/deploy-on-kubernetes/greptimedb-operator-management.md#upgrade) guide.

## Frontend Groups Configuration

:::tip NOTE
The configuration structure has changed between chart versions:

- In older version: `meta.etcdEndpoints`
- In newer version: `meta.backendStorage.etcd.endpoints`

Always refer to the latest [values.yaml](https://github.com/GreptimeTeam/helm-charts/blob/main/charts/greptimedb-cluster/values.yaml) in the Helm chart repository for the most up-to-date configuration structure.
:::

When configuring frontend groups, ensure that each group includes a `name` field. The following `values.yaml` example demonstrates how to define separate frontend groups for read and write operations:

```yaml
frontend:
  enabled: false  # Disable default frontend group

frontendGroups:
  - name: read
    replicas: 1
    config: |
      default_timezone = "UTC"
      [http]
      timeout = "60s"
    template:
      main:
        resources:
          limits:
            cpu: 2000m
            memory: 2048Mi
  - name: write
    replicas: 1

meta:
  replicas: 1
  backendStorage:
    etcd:
      endpoints:
        - "etcd.etcd-cluster.svc.cluster.local:2379"

datanode:
  replicas: 1
```

You can use the following command to apply the configuration:
```
helm upgrade --install ${release-name} greptime/greptimedb-cluster --namespace ${namespace} -f values.yaml
```

## Validity

When setting the frontend groups, the name must be set.

```yaml
frontendGroups: 
  #  - name: read #<=========The name must be set=============>
  - replicas: 1
```    

## Verify the Installation

Check the status of the pods:

```bash
kubectl get pods -n default
NAME                                        READY   STATUS    RESTARTS   AGE
greptimedb-datanode-0                       1/1     Running   0          27s
greptimedb-frontend-read-66bf68bd5c-8kg8g   1/1     Running   0          21s
greptimedb-frontend-read-66bf68bd5c-x752l   1/1     Running   0          21s
greptimedb-frontend-write-bdd944b97-pkf9d   1/1     Running   0          21s
greptimedb-meta-699f74cd9d-42w2c            1/1     Running   0          87s
```

To check the services:

```bash
kubectl get service -n default
NAME                        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                               AGE
greptimedb-datanode         ClusterIP   None            <none>        4001/TCP,4000/TCP                     102s
greptimedb-frontend-read    ClusterIP   10.96.174.200   <none>        4001/TCP,4000/TCP,4002/TCP,4003/TCP   42s
greptimedb-frontend-write   ClusterIP   10.96.223.1     <none>        4001/TCP,4000/TCP,4002/TCP,4003/TCP   42s
greptimedb-meta             ClusterIP   10.96.195.163   <none>        3002/TCP,4000/TCP                     3m4s
```

## Conclusion

You have successfully deployed a GreptimeDB cluster with a frontend group consisting of read and write instances. You can now proceed to explore the functionality of your GreptimeDB cluster or integrate it with additional tools as needed.