Cluster Deployment

It's highly recommended to deploy the GreptimeDB cluster in Kubernetes. There are the following prerequires:

• Kubernetes(>=1.18)

  For testing purposes, you can use Kind or Minikube to create Kubernetes.

• Helm v3

• kubectl

Step 1: Deploy the GreptimeDB Operator

Add the chart repository with the following commands:

helm repo add greptime https://greptimeteam.github.io/helm-charts/
helm repo update

Create the greptimedb-admin namespace and deploy the GreptimeDB operator in the namespace:

kubectl create ns greptimedb-admin
helm upgrade --install greptimedb-operator greptime/greptimedb-operator -n greptimedb-admin

Step 2: Deploy the etcd Cluster

The GreptimeDB cluster needs the etcd cluster as the backend storage of the metasrv. We recommend using the Bitnami etcd chart to deploy the etcd cluster:

kubectl create ns metasrv-store
helm upgrade --install etcd oci://registry-1.docker.io/bitnamicharts/etcd \
  --set replicaCount=3 \
  --set auth.rbac.create=false \
  --set auth.rbac.token.enabled=false \
  -n metasrv-store

When the etcd cluster is ready, you can use the following command to check the cluster health:

kubectl -n metasrv-store \
  exec etcd-0 -- etcdctl \
  --endpoints etcd-0.etcd-headless.metasrv-store:2379,etcd-1.etcd-headless.metasrv-store:2379,etcd-2.etcd-headless.metasrv-store:2379 \
  endpoint status

Step 3: Deploy the Kafka Cluster

We recommend using strimzi-kafka-operator to deploy the Kafka cluster in KRaft mode.

Create the kafka namespace and install the strimzi-kafka-operator:

kubectl create namespace kafka
kubectl create -f 'https://strimzi.io/install/latest?namespace=kafka' -n kafka

When the operator is ready, use the following spec to create the Kafka cluster:

apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaNodePool
metadata:
  name: dual-role
  labels:
    strimzi.io/cluster: kafka-wal
spec:
  replicas: 3
  roles:
    - controller
    - broker
  storage:
    type: jbod
    volumes:
      - id: 0
        type: persistent-claim
        size: 20Gi
        deleteClaim: false
---

apiVersion: kafka.strimzi.io/v1beta2
kind: Kafka
metadata:
  name: kafka-wal
  annotations:
    strimzi.io/node-pools: enabled
    strimzi.io/kraft: enabled
spec:
  kafka:
    version: 3.7.0
    metadataVersion: 3.7-IV4
    listeners:
      - name: plain
        port: 9092
        type: internal
        tls: false
      - name: tls
        port: 9093
        type: internal
        tls: true
    config:
      offsets.topic.replication.factor: 3
      transaction.state.log.replication.factor: 3
      transaction.state.log.min.isr: 2
      default.replication.factor: 3
      min.insync.replicas: 2
  entityOperator:
    topicOperator: {}
    userOperator: {}

Save the spec as kafka-wal.yaml and apply in the Kubernetes:

kubectl apply -f kafka-wal.yaml -n kafka

After the Kafka cluster is ready, check the status:

kubectl get kafka -n kafka

The expected output will be:

NAME        DESIRED KAFKA REPLICAS   DESIRED ZK REPLICAS   READY   METADATA STATE   WARNINGS
kafka-wal                                                  True    KRaft

Step 4: Deploy the GreptimeDB Cluster with Remote WAL Settings

Create a GreptimeDB cluster with remote WAL settings:

cat <<EOF | kubectl apply -f -
apiVersion: greptime.io/v1alpha1
kind: GreptimeDBCluster
metadata:
  name: my-cluster
  namespace: default
spec:
  base:
    main:
      image: greptime/greptimedb:latest
  frontend:
    replicas: 1
  meta:
    replicas: 1
    etcdEndpoints:
      - "etcd.metasrv-store:2379"
  datanode:
    replicas: 3
  remoteWal:
    kafka:
      brokerEndpoints:
        - "kafka-wal-kafka-bootstrap.kafka:9092"
EOF

When the GreptimeDB cluster is ready, you can check the cluster status:

kubectl get gtc my-cluster -n default

The expected output will be:

NAME         FRONTEND   DATANODE   META   PHASE     VERSION   AGE
my-cluster   1          3          1      Running   latest    5m30s

Step 5: Write and Query Data

Let's choose to connect the cluster using the MySQL protocol. Use the kubectl to port forward 4002 traffic:

kubectl port-forward svc/my-cluster-frontend 4002:4002 -n default

Open another terminal and connect the cluster by mysql:

mysql -h 127.0.0.1 -P 4002

Create a distributed table:

CREATE TABLE dist_table(
    ts TIMESTAMP DEFAULT current_timestamp(),
    n INT,
    row_id INT,
    PRIMARY KEY(n),
    TIME INDEX (ts)
)
PARTITION ON COLUMNS (n) (
    n < 5,
    n >= 5 AND n < 9,
    n >= 9
)
engine=mito;

Write the data:

INSERT INTO dist_table(n, row_id) VALUES (1, 1);
INSERT INTO dist_table(n, row_id) VALUES (2, 2);
INSERT INTO dist_table(n, row_id) VALUES (3, 3);
INSERT INTO dist_table(n, row_id) VALUES (4, 4);
INSERT INTO dist_table(n, row_id) VALUES (5, 5);
INSERT INTO dist_table(n, row_id) VALUES (6, 6);
INSERT INTO dist_table(n, row_id) VALUES (7, 7);
INSERT INTO dist_table(n, row_id) VALUES (8, 8);
INSERT INTO dist_table(n, row_id) VALUES (9, 9);
INSERT INTO dist_table(n, row_id) VALUES (10, 10);
INSERT INTO dist_table(n, row_id) VALUES (11, 11);
INSERT INTO dist_table(n, row_id) VALUES (12, 12);

And query the data:

SELECT * from dist_table;