Overview
KubeDB is the Kubernetes Native Database Management Solution which simplifies and automates routine database tasks such as Provisioning, Monitoring, Upgrading, Patching, Scaling, Volume Expansion, Backup, Recovery, Failure detection, and Repair for various popular databases on private and public clouds. The databases that KubeDB supports are MongoDB, Elasticsearch, MySQL, MariaDB, Kafka, Redis, PostgreSQL, ProxySQL, Percona XtraDB, Memcached and PgBouncer. You can find the guides to all the supported databases in KubeDB . In this tutorial we will show Horizontal scaling of MySQL cluster in Amazon Elastic Kubernetes Service (Amazon EKS). We will cover the following steps:
- Install KubeDB
- Deploy MySQL Cluster
- Read/Write Sample Data
- Horizontal Scaling of MySQL Cluster
Get Cluster ID
We need the cluster ID to get the KubeDB License. To get cluster ID, we can run the following command:
$ kubectl get ns kube-system -o jsonpath='{.metadata.uid}'
8e336615-0dbb-4ae8-b72f-2e7ec34c399d
Get License
Go to Appscode License Server to get the license.txt file. For this tutorial we will use KubeDB.
Install KubeDB
We will use helm to install KubeDB. Please install helm here
if it is not already installed.
Now, let’s install KubeDB.
$ helm install kubedb oci://ghcr.io/appscode-charts/kubedb \
--version v2023.12.21 \
--namespace kubedb --create-namespace \
--set-file global.license=/path/to/the/license.txt \
--wait --burst-limit=10000 --debug
$ helm search repo appscode/kubedb
NAME CHART VERSION APP VERSION DESCRIPTION
appscode/kubedb v2023.12.11 v2023.12.11 KubeDB by AppsCode - Production ready databases...
appscode/kubedb-autoscaler v0.23.0 v0.23.0 KubeDB Autoscaler by AppsCode - Autoscale KubeD...
appscode/kubedb-catalog v2023.12.11 v2023.12.11 KubeDB Catalog by AppsCode - Catalog for databa...
appscode/kubedb-community v0.24.2 v0.24.2 KubeDB Community by AppsCode - Community featur...
appscode/kubedb-crds v2023.12.11 v2023.12.11 KubeDB Custom Resource Definitions
appscode/kubedb-dashboard v0.14.0 v0.14.0 KubeDB Dashboard by AppsCode
appscode/kubedb-enterprise v0.11.2 v0.11.2 KubeDB Enterprise by AppsCode - Enterprise feat...
appscode/kubedb-grafana-dashboards v2023.12.11 v2023.12.11 A Helm chart for kubedb-grafana-dashboards by A...
appscode/kubedb-kubestash-catalog v2023.12.11 v2023.12.11 KubeStash Catalog by AppsCode - Catalog of Kube...
appscode/kubedb-metrics v2023.12.11 v2023.12.11 KubeDB State Metrics
appscode/kubedb-one v2023.12.11 v2023.12.11 KubeDB and Stash by AppsCode - Production ready...
appscode/kubedb-ops-manager v0.25.0 v0.25.0 KubeDB Ops Manager by AppsCode - Enterprise fea...
appscode/kubedb-opscenter v2023.12.11 v2023.12.11 KubeDB Opscenter by AppsCode
appscode/kubedb-provider-aws v2023.12.11 v0.0.2 A Helm chart for KubeDB AWS Provider for Crossp...
appscode/kubedb-provider-azure v2023.12.11 v0.0.2 A Helm chart for KubeDB Azure Provider for Cros...
appscode/kubedb-provider-gcp v2023.12.11 v0.0.2 A Helm chart for KubeDB GCP Provider for Crossp...
appscode/kubedb-provisioner v0.38.0 v0.38.1 KubeDB Provisioner by AppsCode - Community feat...
appscode/kubedb-schema-manager v0.14.0 v0.14.0 KubeDB Schema Manager by AppsCode
appscode/kubedb-ui v2023.12.5 0.6.1-alpha.2 A Helm chart for Kubernetes
appscode/kubedb-ui-server v2021.12.21 v2021.12.21 A Helm chart for kubedb-ui-server by AppsCode
appscode/kubedb-webhook-server v0.14.0 v0.14.0 KubeDB Webhook Server by AppsCode
Let’s verify the installation:
$ kubectl get pods --all-namespaces -l "app.kubernetes.io/instance=kubedb"
NAMESPACE NAME READY STATUS RESTARTS AGE
kubedb kubedb-kubedb-autoscaler-85cd95b566-s28kp 1/1 Running 0 86s
kubedb kubedb-kubedb-dashboard-755cd987b9-qzrxw 1/1 Running 0 86s
kubedb kubedb-kubedb-ops-manager-5f6554ff87-z76f4 1/1 Running 0 86s
kubedb kubedb-kubedb-provisioner-7d96496655-rlthn 1/1 Running 0 86s
kubedb kubedb-kubedb-schema-manager-75659b84bb-hwx6j 1/1 Running 0 86s
kubedb kubedb-kubedb-webhook-server-ffd7d5659-ndr5d 1/1 Running 0 86s
We can list the CRD Groups that have been registered by the operator by running the following command:
$ kubectl get crd -l app.kubernetes.io/name=kubedb
NAME CREATED AT
elasticsearchautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:07Z
elasticsearchdashboards.dashboard.kubedb.com 2023-12-15T09:12:05Z
elasticsearches.kubedb.com 2023-12-15T09:12:05Z
elasticsearchopsrequests.ops.kubedb.com 2023-12-15T09:12:17Z
elasticsearchversions.catalog.kubedb.com 2023-12-15T09:09:58Z
etcds.kubedb.com 2023-12-15T09:12:20Z
etcdversions.catalog.kubedb.com 2023-12-15T09:09:59Z
kafkaopsrequests.ops.kubedb.com 2023-12-15T09:13:10Z
kafkas.kubedb.com 2023-12-15T09:12:29Z
kafkaversions.catalog.kubedb.com 2023-12-15T09:09:59Z
mariadbautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:07Z
mariadbopsrequests.ops.kubedb.com 2023-12-15T09:12:46Z
mariadbs.kubedb.com 2023-12-15T09:12:21Z
mariadbversions.catalog.kubedb.com 2023-12-15T09:09:59Z
memcacheds.kubedb.com 2023-12-15T09:12:21Z
memcachedversions.catalog.kubedb.com 2023-12-15T09:10:00Z
mongodbarchivers.archiver.kubedb.com 2023-12-15T09:12:33Z
mongodbautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:07Z
mongodbopsrequests.ops.kubedb.com 2023-12-15T09:12:21Z
mongodbs.kubedb.com 2023-12-15T09:12:22Z
mongodbversions.catalog.kubedb.com 2023-12-15T09:10:00Z
mysqlautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:07Z
mysqlopsrequests.ops.kubedb.com 2023-12-15T09:12:42Z
mysqls.kubedb.com 2023-12-15T09:12:24Z
mysqlversions.catalog.kubedb.com 2023-12-15T09:10:00Z
perconaxtradbautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:07Z
perconaxtradbopsrequests.ops.kubedb.com 2023-12-15T09:13:03Z
perconaxtradbs.kubedb.com 2023-12-15T09:12:24Z
perconaxtradbversions.catalog.kubedb.com 2023-12-15T09:10:01Z
pgbouncers.kubedb.com 2023-12-15T09:12:26Z
pgbouncerversions.catalog.kubedb.com 2023-12-15T09:10:01Z
postgresarchivers.archiver.kubedb.com 2023-12-15T09:12:36Z
postgresautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:08Z
postgreses.kubedb.com 2023-12-15T09:12:27Z
postgresopsrequests.ops.kubedb.com 2023-12-15T09:12:55Z
postgresversions.catalog.kubedb.com 2023-12-15T09:10:01Z
proxysqlautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:08Z
proxysqlopsrequests.ops.kubedb.com 2023-12-15T09:12:59Z
proxysqls.kubedb.com 2023-12-15T09:12:27Z
proxysqlversions.catalog.kubedb.com 2023-12-15T09:10:01Z
publishers.postgres.kubedb.com 2023-12-15T09:13:14Z
redisautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:08Z
redises.kubedb.com 2023-12-15T09:12:28Z
redisopsrequests.ops.kubedb.com 2023-12-15T09:12:49Z
redissentinelautoscalers.autoscaling.kubedb.com 2023-12-15T09:12:09Z
redissentinelopsrequests.ops.kubedb.com 2023-12-15T09:13:06Z
redissentinels.kubedb.com 2023-12-15T09:12:29Z
redisversions.catalog.kubedb.com 2023-12-15T09:10:02Z
subscribers.postgres.kubedb.com 2023-12-15T09:13:18Z
Deploy MySQL Cluster
We are going to Deploy MySQL Cluster using KubeDB. First, let’s create a Namespace in which we will deploy the database.
$ kubectl create namespace demo
namespace/demo created
Here is the yaml of the MySQL CR we are going to use:
apiVersion: kubedb.com/v1alpha2
kind: MySQL
metadata:
name: mysql-cluster
namespace: demo
spec:
version: "8.1.0"
replicas: 3
topology:
mode: GroupReplication
storageType: Durable
storage:
storageClassName: "gp2"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
terminationPolicy: WipeOut
Let’s save this yaml configuration into mysql-cluster.yaml
Then create the above MySQL CR
$ kubectl apply -f mysql-cluster.yaml
mysql.kubedb.com/mysql-cluster created
In this yaml,
- In this yaml we can see in the
spec.versionfield specifies the version of MySQL. Here, we are using MySQL8.1.0. You can list the KubeDB supported versions of MySQL by running$ kubectl get mysqlversionscommand. spec.topologyrepresents the clustering configuration for MySQL.spec.topology.modespecifies the mode for MySQL cluster. Here we have usedGroupReplication.spec.storage.storageClassNameis the name of the StorageClass used to provision PVCs.spec.terminationPolicyfield is Wipeout means that the database will be deleted without restrictions. It can also be “Halt”, “Delete” and “DoNotTerminate”. Learn More about these checkout Termination Policy .
Once these are handled correctly and the MySQL object is deployed, you will see that the following objects are created:
$ kubectl get all -n demo
NAME READY STATUS RESTARTS AGE
pod/mysql-cluster-0 2/2 Running 0 4m
pod/mysql-cluster-1 2/2 Running 0 4m
pod/mysql-cluster-2 2/2 Running 0 3m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/mysql-cluster ClusterIP 10.44.22.110 <none> 3306/TCP 5m
service/mysql-cluster-pods ClusterIP None <none> 3306/TCP 5m
service/mysql-cluster-standby ClusterIP 10.44.19.195 <none> 3306/TCP 5m
NAME READY AGE
statefulset.apps/mysql-cluster 3/3 5m
NAME TYPE VERSION AGE
appbinding.appcatalog.appscode.com/mysql-cluster kubedb.com/mysql 8.1.0 5m
NAME VERSION STATUS AGE
mysql.kubedb.com/mysql-cluster 8.1.0 Ready 5m
Let’s check if the database is ready to use,
$ kubectl get mysql -n demo mysql-cluster
NAME VERSION STATUS AGE
mysql-cluster 8.1.0 Ready 6m
We have successfully deployed MySQL cluster in AWS. Now we can exec into the container to use the database.
Accessing Database Through CLI
To access the database through CLI, we have to get the credentials to access. KubeDB will create Secret and Service for the database mysql-cluster that we have deployed. Let’s check them using the following commands,
$ kubectl get secret -n demo -l=app.kubernetes.io/instance=mysql-cluster
NAME TYPE DATA AGE
mysql-cluster-auth kubernetes.io/basic-auth 2 16m
$ kubectl get service -n demo -l=app.kubernetes.io/instance=mysql-cluster
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
mysql-cluster ClusterIP 10.44.22.110 <none> 3306/TCP 17m
mysql-cluster-pods ClusterIP None <none> 3306/TCP 17m
mysql-cluster-standby ClusterIP 10.44.19.195 <none> 3306/TCP 17m
Now, we are going to use mysql-cluster-auth to get the credentials.
$ kubectl get secrets -n demo mysql-cluster-auth -o jsonpath='{.data.username}' | base64 -d
root
$ kubectl get secrets -n demo mysql-cluster-auth -o jsonpath='{.data.password}' | base64 -d
ME2x7)YrLb4L!asY
Insert Sample Data
In this section, we are going to login into our MySQL database pod and insert some sample data.
$ kubectl exec -it mysql-cluster-0 -n demo -c mysql -- bash
bash-4.4# mysql --user=root --password='ME2x7)YrLb4L!asY'
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 384
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> CREATE DATABASE Music;
Query OK, 1 row affected (0.01 sec)
mysql> CREATE TABLE Music.Artist (id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY, Name VARCHAR(50), Song VARCHAR(50));
Query OK, 0 rows affected, 1 warning (0.02 sec)
mysql> INSERT INTO Music.Artist (Name, Song) VALUES ("John Denver", "Annie's Song");
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM Music.Artist;
+----+-------------+---------------+
| id | Name | Song |
+----+-------------+---------------+
| 1 | John Denver | Annie's Song |
+----+-------------+---------------+
1 row in set (0.00 sec)
mysql> exit
Bye
We’ve successfully inserted some sample data to our database. More information about Run & Manage MySQL on Kubernetes can be found in Kubernetes MySQL
Horizontal Scaling of MySQL Cluster
Horizontal Scale Up
Here, we are going to scale up the replicas of the MySQL cluster replicaset to meet the desired number of replicas after scaling. Before applying Horizontal Scaling, let’s check the current number of replicas,
$ kubectl get mysql -n demo mysql-cluster -o json | jq '.spec.replicas'
3
Create MySQLOpsRequest
In order to scale up, we have to create a MySQLOpsRequest CR with our desired replicas. Let’s create it using this following yaml,
apiVersion: ops.kubedb.com/v1alpha1
kind: MySQLOpsRequest
metadata:
name: horizontal-scale-up
namespace: demo
spec:
type: HorizontalScaling
databaseRef:
name: mysql-cluster
horizontalScaling:
member: 5
In this yaml,
spec.databaseRef.namespecifies that we are performing horizontal scaling operation onmysql-clusterdatabase.spec.typespecifies that we are performingHorizontalScalingon our database.spec.horizontalScaling.memberspecifies the desired number of replicas after scaling.
Let’s save this yaml configuration into horizontal-scale-up.yaml and apply it,
$ kubectl apply -f horizontal-scale-up.yaml
mysqlopsrequest.ops.kubedb.com/horizontal-scale-up created
Let’s wait for MySQLOpsRequest STATUS to be Successful. Run the following command to watch MySQLOpsRequest CR,
$ watch kubectl get mysqlopsrequest -n demo
NAME TYPE STATUS AGE
horizontal-scale-up HorizontalScaling Successful 2m39s
From the above output we can see that the MySQLOpsRequest has succeeded. Now, we are going to verify the number of replicas,
$ kubectl get mysql -n demo mysql-cluster -o json | jq '.spec.replicas'
5
From all the above outputs we can see that the replicas of the cluster is now increased to 5. That means we have successfully scaled up the replicas of the MySQL cluster.
Horizontal Scale Down
Now, we are going to scale down the replicas of the cluster to meet the desired number of replicas after scaling.
Create MySQLOpsRequest
In order to scale down, again we need to create a MySQLOpsRequest CR with our desired replicas. Let’s create it using this following yaml,
apiVersion: ops.kubedb.com/v1alpha1
kind: MySQLOpsRequest
metadata:
name: horizontal-scale-down
namespace: demo
spec:
type: HorizontalScaling
databaseRef:
name: mysql-cluster
horizontalScaling:
member: 3
In this yaml,
spec.databaseRef.namespecifies that we are performing horizontal scaling operation onmysql-clusterdatabase.spec.typespecifies that we are performingHorizontalScalingon our database.spec.horizontalScaling.memberspecifies the desired number of replicas after scaling.
Let’s save this yaml configuration into horizontal-scale-down.yaml and apply it,
$ kubectl apply -f horizontal-scale-down.yaml
mysqlopsrequest.ops.kubedb.com/horizontal-scale-down created
Let’s wait for MySQLOpsRequest STATUS to be Successful. Run the following command to watch MySQLOpsRequest CR,
$ watch kubectl get mysqlopsrequest -n demo
NAME TYPE STATUS AGE
horizontal-scale-down HorizontalScaling Successful 2m18s
From the above output we can see that the MySQLOpsRequest has succeeded. Now, we are going to verify the number of replicas,
$ kubectl get mysql -n demo mysql-cluster -o json | jq '.spec.replicas'
3
From all the above outputs we can see that the replicas of the cluster is decreased to 3. That means we have successfully scaled down the replicas of the MySQL cluster.
If you want to learn more about Production-Grade MySQL on Kubernetes you can have a look into that playlist below:
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More about MySQL in Kubernetes
If you have found a bug with KubeDB or want to request for new features, please file an issue .