What we can learn from this post?

Deploy the NDB operator into k8s node

The MySQL NDB Operator is a k8s operator, use it to manage the NDB cluster.

  1. Use the office configure to deploy it
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kubectl apply -f https://raw.githubusercontent.com/mysql/mysql-ndb-operator/main/deploy/manifests/ndb-operator.yaml
  1. Check the operator pods
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kubectl get pods -n ndb-operator

The output should be similar with:

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NAME                                          READY   STATUS    RESTARTS   AGE
ndb-operator-app-54d6f946d5-cmpjb             1/1     Running   0          2m54s
ndb-operator-webhook-server-c66cbd8bc-sk56c   1/1     Running   0          2m54s

Create a NDB Cluster

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apiVersion: mysql.oracle.com/v1alpha1
kind: NdbCluster
metadata:
  name: mysql-ndb
spec:
  nodeCount: 2 # Number of Data Nodes
  redundancyLevel: 2 # MySQL Cluster Replica
  dataNodeConfig:
    DataMemory: 100M
    MaxNoOfTables: 1024
    MaxNoOfConcurrentOperations: 409600
    Arbitration: WaitExternal
  dataNodePVCSpec:
    storageClassName: manual
    accessModes:
      - ReadWriteOnce
    resources:
      requests:
        storage: 20Gi
  mysqld:
    nodeCount: 2 # Number of MySQL Servers

    myCnf: |
      [mysqld]
      max-user-connections = 42
      ndb-extra-logging = 20
      expire-logs-days = 30

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: ndb-pv1
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/data/ndb_data/node1"
    type: DirectoryOrCreate

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: ndb-pv2
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/data/ndb_data/node2"
    type: DirectoryOrCreate

From the above configure, we can deploy the NDB cluster into the k8s. It includes two SQL nodes and two Data Nodes.

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kubectl apply -f k8s/ndb.yaml

To get the example mysql-ndb cluster pods

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kubectl get pods -l mysql.oracle.com/v1alpha1=mysql-ndb

The output is similar with:

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NAME                                READY   STATUS    RESTARTS    AGE
mysql-ndb-mgmd-0                    1/1     Running   0           5m10s
mysql-ndb-mgmd-1                    1/1     Running   0           3m5s
mysql-ndb-mysqld-5549c5b96c-b4ck6   1/1     Running   0           1m10s
mysql-ndb-mysqld-5549c5b96c-tfbdl   1/1     Running   0           1m10s
mysql-ndb-ndbd-0                    1/1     Running   0           5m10s
mysql-ndb-ndbd-1                    1/1     Running   0           5m10s

For the above output, we can see the cluster contains two management nodes *-mgmd-*, two data nodes *-ndbd-*
and two MySQL servers *-mtsqld-*.

Connect to the NDB cluster

Get the cluster’s services

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kubectl get services -l mysql.oracle.com/v1alpha1=mysql-ndb

The output would be similar with:

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NAME               TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
mysql-ndb-mgmd     ClusterIP   10.104.206.41   <none>        1186/TCP   1d18h
mysql-ndb-mysqld   ClusterIP   10.106.0.201    <none>        3306/TCP   1d18h
mysql-ndb-ndbd     ClusterIP   None            <none>        1186/TCP   1d18h

Now we can connect to the MySQL service by the service name mysql-ndb-mysqld and 3306 port.
The password for root user can get from this command:

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kubectl get secret $(kubectl get ndb mysql-ndb -o jsonpath={.status.generatedRootPasswordSecretName}) \
    -o jsonpath={.data.password} | base64 -d

Connect to MySQL in one K8s pod

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kubectl exec -it mysql-ndb-mysqld-5549c5b96c-b4ck6 -- bash
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mysql -h mysql-ndb-mysqld -u root -p
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ndb_mgm -c mysql-ndb-mgmd

-- NDB Cluster -- Management Client --
ndb_mgm> show
Connected to Management Server at: mysql-ndb-mgmd:1186
Cluster Configuration
---------------------
[ndbd(NDB)]     2 node(s)
id=3    @172.17.0.15  (mysql-8.0.29 ndb-8.0.29, Nodegroup: 0, *)
id=4    @172.17.0.7  (mysql-8.0.29 ndb-8.0.29, Nodegroup: 0)

[ndb_mgmd(MGM)] 2 node(s)
id=1    @172.17.0.3  (mysql-8.0.29 ndb-8.0.29)
id=2    @172.17.0.8  (mysql-8.0.29 ndb-8.0.29)

[mysqld(API)]   8 node(s)
id=145  @172.17.0.4  (mysql-8.0.29 ndb-8.0.29)
id=146  @172.17.0.10  (mysql-8.0.29 ndb-8.0.29)
id=147 (not connected, accepting connect from any host)
id=148 (not connected, accepting connect from any host)
id=149 (not connected, accepting connect from any host)
id=150 (not connected, accepting connect from any host)
id=151 (not connected, accepting connect from any host)
id=152 (not connected, accepting connect from any host)

Connect to MySQL from outside K8s

The default NDB Cluster no expose for outside, we need to enable the load balancers to enable access from outside

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kubectl patch ndb mysql-ndb --type='merge' \
    -p '{"spec":{"enableManagementNodeLoadBalancer":true,"mysqld":{"enableLoadBalancer":true}}}'

We can check the expose ports from this command:

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kubectl get services -l mysql.oracle.com/v1alpha1=mysql-ndb

The output will be similar as:

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NAME               TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
mysql-ndb-mgmd     LoadBalancer   10.104.206.41   <pending>     1186:31367/TCP   1d4h
mysql-ndb-mysqld   LoadBalancer   10.106.0.201    <pending>     3306:30783/TCP   1d4h
mysql-ndb-ndbd     ClusterIP      None            <none>        1186/TCP         1d4h

Connect through mysql tool

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mysql -h $(minikube ip) -P 30783 -u root -p