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Reconfigure MariaDB Cluster Database
This guide will show you how to use KubeDB Enterprise operator to reconfigure a MariaDB Cluster.
Before You Begin
At first, you need to have a Kubernetes cluster, and the
kubectlcommand-line tool must be configured to communicate with your cluster.Install
KubeDBCommunity and Enterprise operator in your cluster following the steps here.You should be familiar with the following
KubeDBconcepts:
To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Now, we are going to deploy a MariaDB Cluster using a supported version by KubeDB operator. Then we are going to apply MariaDBOpsRequest to reconfigure its configuration.
Prepare MariaDB Cluster
Now, we are going to deploy a MariaDB Cluster database with version 10.6.4.
Deploy MariaDB
At first, we will create md-config.cnf file containing required configuration settings.
$ cat md-config.cnf
[mysqld]
max_connections = 200
read_buffer_size = 1048576
Here, max_connections is set to 200, whereas the default value is 151. Likewise, read_buffer_size has the deafult value 131072.
Now, we will create a secret with this configuration file.
$ kubectl create secret generic -n demo md-configuration --from-file=./md-config.cnf
secret/md-configuration created
In this section, we are going to create a MariaDB object specifying spec.configSecret field to apply this custom configuration. Below is the YAML of the MariaDB CR that we are going to create,
apiVersion: kubedb.com/v1alpha2
kind: MariaDB
metadata:
name: sample-mariadb
namespace: demo
spec:
version: "10.6.4"
replicas: 3
configSecret:
name: md-configuration
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
terminationPolicy: WipeOut
Let’s create the MariaDB CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2022.12.24-rc.1/docs/guides/mariadb/reconfigure/cluster/examples/sample-mariadb-config.yaml
mariadb.kubedb.com/sample-mariadb created
Now, wait until sample-mariadb has status Ready. i.e,
$ kubectl get mariadb -n demo
NAME VERSION STATUS AGE
sample-mariadb 10.6.4 Ready 71s
Now, we will check if the database has started with the custom configuration we have provided.
First we need to get the username and password to connect to a mariadb instance,
$ kubectl get secrets -n demo sample-mariadb-auth -o jsonpath='{.data.\username}' | base64 -d
root
$ kubectl get secrets -n demo sample-mariadb-auth -o jsonpath='{.data.\password}' | base64 -d
nrKuxni0wDSMrgwy
Now, we will check if the database has started with the custom configuration we have provided.
$ kubectl exec -it -n demo sample-mariadb-0 -- bash
root@sample-mariadb-0:/ mysql -u${MYSQL_ROOT_USERNAME} -p${MYSQL_ROOT_PASSWORD}
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 23
Server version: 10.6.4-MariaDB-1:10.6.4+maria~focal mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
# value of `max_conncetions` is same as provided
MariaDB [(none)]> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 200 |
+-----------------+-------+
1 row in set (0.001 sec)
# value of `read_buffer_size` is same as provided
MariaDB [(none)]> show variables like 'read_buffer_size';
+------------------+---------+
| Variable_name | Value |
+------------------+---------+
| read_buffer_size | 1048576 |
+------------------+---------+
1 row in set (0.001 sec)
MariaDB [(none)]> exit
Bye
As we can see from the configuration of ready mariadb, the value of max_connections has been set to 200 and read_buffer_size has been set to 1048576.
Reconfigure using new config secret
Now we will reconfigure this database to set max_connections to 250 and read_buffer_size to 122880.
Now, we will create new file new-md-config.cnf containing required configuration settings.
$ cat new-md-config.cnf
[mysqld]
max_connections = 250
read_buffer_size = 122880
Then, we will create a new secret with this configuration file.
$ kubectl create secret generic -n demo new-md-configuration --from-file=./new-md-config.cnf
secret/new-md-configuration created
Create MariaDBOpsRequest
Now, we will use this secret to replace the previous secret using a MariaDBOpsRequest CR. The MariaDBOpsRequest yaml is given below,
apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
name: mdops-reconfigure-config
namespace: demo
spec:
type: Reconfigure
databaseRef:
name: sample-mariadb
configuration:
configSecret:
name: new-md-configuration
Here,
spec.databaseRef.namespecifies that we are reconfiguringsample-mariadbdatabase.spec.typespecifies that we are performingReconfigureon our database.spec.configuration.configSecret.namespecifies the name of the new secret.
Let’s create the MariaDBOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2022.12.24-rc.1/docs/guides/mariadb/reconfigure/cluster/examples/reconfigure-using-secret.yaml
mariadbopsrequest.ops.kubedb.com/mdops-reconfigure-config created
Verify the new configuration is working
If everything goes well, KubeDB Enterprise operator will update the configSecret of MariaDB object.
Let’s wait for MariaDBOpsRequest to be Successful. Run the following command to watch MariaDBOpsRequest CR,
$ kubectl get mariadbopsrequest --all-namespaces
NAMESPACE NAME TYPE STATUS AGE
demo mdops-reconfigure-config Reconfigure Successful 3m8s
We can see from the above output that the MariaDBOpsRequest has succeeded. If we describe the MariaDBOpsRequest we will get an overview of the steps that were followed to reconfigure the database.
$ kubectl describe mariadbopsrequest -n demo mdops-reconfigure-config
Name: mdops-reconfigure-config
Namespace: demo
Labels: <none>
Annotations: <none>
API Version: ops.kubedb.com/v1alpha1
Kind: MariaDBOpsRequest
Metadata:
Creation Timestamp: 2022-06-10T04:43:50Z
Generation: 1
Resource Version: 1123451
UID: 27a73fc6-1d25-4019-8975-f7d4daf782b7
Spec:
Configuration:
Config Secret:
Name: new-md-configuration
Database Ref:
Name: sample-mariadb
Type: Reconfigure
Status:
Conditions:
Last Transition Time: 2022-06-10T04:43:50Z
Message: Controller has started to Progress the MariaDBOpsRequest: demo/mdops-reconfigure-config
Observed Generation: 1
Reason: OpsRequestProgressingStarted
Status: True
Type: Progressing
Last Transition Time: 2022-06-10T04:47:25Z
Message: Successfully restarted MariaDB pods for MariaDBOpsRequest: demo/mdops-reconfigure-config
Observed Generation: 1
Reason: SuccessfullyRestatedStatefulSet
Status: True
Type: RestartStatefulSetPods
Last Transition Time: 2022-06-10T04:47:30Z
Message: Successfully reconfigured MariaDB for MariaDBOpsRequest: demo/mdops-reconfigure-config
Observed Generation: 1
Reason: SuccessfullyDBReconfigured
Status: True
Type: DBReady
Last Transition Time: 2022-06-10T04:47:30Z
Message: Controller has successfully reconfigure the MariaDB demo/mdops-reconfigure-config
Observed Generation: 1
Reason: OpsRequestProcessedSuccessfully
Status: True
Type: Successful
Observed Generation: 3
Phase: Successful
Now let’s connect to a mariadb instance and run a mariadb internal command to check the new configuration we have provided.
$ kubectl exec -it -n demo sample-mariadb-0 -- bash
root@sample-mariadb-0:/ mysql -u${MYSQL_ROOT_USERNAME} -p${MYSQL_ROOT_PASSWORD}
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 23
Server version: 10.6.4-MariaDB-1:10.6.4+maria~focal mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
# value of `max_conncetions` is same as provided
MariaDB [(none)]> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 250 |
+-----------------+-------+
1 row in set (0.001 sec)
# value of `read_buffer_size` is same as provided
MariaDB [(none)]> show variables like 'read_buffer_size';
+------------------+---------+
| Variable_name | Value |
+------------------+---------+
| read_buffer_size | 122880 |
+------------------+---------+
1 row in set (0.001 sec)
MariaDB [(none)]> exit
Bye
As we can see from the configuration has changed, the value of max_connections has been changed from 200 to 250 and and the read_buffer_size has been changed 1048576 to 122880. So the reconfiguration of the database is successful.
Reconfigure Existing Config Secret
Now, we will create a new MariaDBOpsRequest to reconfigure our existing secret new-md-configuration by modifying our new-md-config.cnf file using applyConfig. The MariaDBOpsRequest yaml is given below,
apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
name: mdops-reconfigure-apply-config
namespace: demo
spec:
type: Reconfigure
databaseRef:
name: sample-mariadb
configuration:
applyConfig:
new-md-config.cnf: |
[mysqld]
max_connections = 230
read_buffer_size = 1064960
innodb-config.cnf: |
[mysqld]
innodb_log_buffer_size = 17408000
Note: You can modify multiple fields of your current configuration using
applyConfig. If you don’t have any secrets thenapplyConfigwill create a secret for you. Here, we modified value of our two existing fields which aremax_connectionsandread_buffer_sizealso, we modified a new fieldinnodb_log_buffer_sizeof our configuration.
Here,
spec.databaseRef.namespecifies that we are reconfiguringsample-mariadbdatabase.spec.typespecifies that we are performingReconfigureon our database.spec.configuration.applyConfigcontains the configuration of existing or newly created secret.
Before applying this yaml we are going to check the existing value of our new field,
$ kubectl exec -it sample-mariadb-0 -n demo -c mariadb -- bash
root@sample-mariadb-0:/# mysql -u${MYSQL_ROOT_USERNAME} -p${MYSQL_ROOT_PASSWORD}
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 23
Server version: 10.6.4-MariaDB-1:10.6.4+maria~focal mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> show variables like 'innodb_log_buffer_size';
+------------------------+----------+
| Variable_name | Value |
+------------------------+----------+
| innodb_log_buffer_size | 16777216 |
+------------------------+----------+
1 row in set (0.001 sec)
MariaDB [(none)]> exit
Bye
Here, we can see the default value for innodb_log_buffer_size is 16777216.
Let’s create the MariaDBOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2022.12.24-rc.1/docs/guides/mariadb/reconfigure/cluster/examples/mdops-reconfigure-apply-config.yaml
mariadbopsrequest.ops.kubedb.com/mdops-reconfigure-apply-config created
Verify the new configuration is working
If everything goes well, KubeDB Enterprise operator will update the configSecret of MariaDB object.
Let’s wait for MariaDBOpsRequest to be Successful. Run the following command to watch MariaDBOpsRequest CR,
$ kubectl get mariadbopsrequest mdops-reconfigure-apply-config -n demo
NAME TYPE STATUS AGE
mdops-reconfigure-apply-config Reconfigure Successful 4m59s
We can see from the above output that the MariaDBOpsRequest has succeeded. If we describe the MariaDBOpsRequest we will get an overview of the steps that were followed to reconfigure the database.
$ kubectl describe mariadbopsrequest -n demo mdops-reconfigure-apply-config
Name: mdops-reconfigure-apply-config
Namespace: demo
Labels: <none>
Annotations: <none>
API Version: ops.kubedb.com/v1alpha1
Kind: MariaDBOpsRequest
Metadata:
Creation Timestamp: 2022-06-10T09:13:49Z
Generation: 1
Resource Version: 14120
UID: eb8d5df5-a0ce-4011-890c-c18c0200b5ac
Spec:
Configuration:
Apply Config:
innodb-config.cnf: [mysqld]
innodb_log_buffer_size = 17408000
new-md-config.cnf: [mysqld]
max_connections = 230
read_buffer_size = 1064960
Database Ref:
Name: sample-mariadb
Type: Reconfigure
Status:
Conditions:
Last Transition Time: 2022-06-10T09:13:49Z
Message: Controller has started to Progress the MariaDBOpsRequest: demo/mdops-reconfigure-apply-config
Observed Generation: 1
Reason: OpsRequestProgressingStarted
Status: True
Type: Progressing
Last Transition Time: 2022-06-10T09:13:49Z
Message: Successfully prepared user provided custom config secret
Observed Generation: 1
Reason: PrepareSecureCustomConfig
Status: True
Type: PrepareCustomConfig
Last Transition Time: 2022-06-10T09:17:24Z
Message: Successfully restarted MariaDB pods for MariaDBOpsRequest: demo/mdops-reconfigure-apply-config
Observed Generation: 1
Reason: SuccessfullyRestatedStatefulSet
Status: True
Type: RestartStatefulSetPods
Last Transition Time: 2022-06-10T09:17:29Z
Message: Successfully reconfigured MariaDB for MariaDBOpsRequest: demo/mdops-reconfigure-apply-config
Observed Generation: 1
Reason: SuccessfullyDBReconfigured
Status: True
Type: DBReady
Last Transition Time: 2022-06-10T09:17:29Z
Message: Controller has successfully reconfigure the MariaDB demo/mdops-reconfigure-apply-config
Observed Generation: 1
Reason: OpsRequestProcessedSuccessfully
Status: True
Type: Successful
Observed Generation: 3
Phase: Successful
Now let’s connect to a mariadb instance and run a mariadb internal command to check the new configuration we have provided.
$ kubectl exec -it -n demo sample-mariadb-0 -- bash
root@sample-mariadb-0:/ mysql -u${MYSQL_ROOT_USERNAME} -p${MYSQL_ROOT_PASSWORD}
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 23
Server version: 10.6.4-MariaDB-1:10.6.4+maria~focal mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
# value of `max_conncetions` is same as provided
MariaDB [(none)]> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 230 |
+-----------------+-------+
1 row in set (0.001 sec)
# value of `read_buffer_size` is same as provided
MariaDB [(none)]> show variables like 'read_buffer_size';
+------------------+---------+
| Variable_name | Value |
+------------------+---------+
| read_buffer_size | 1064960 |
+------------------+---------+
1 row in set (0.001 sec)
# value of `innodb_log_buffer_size` is same as provided
MariaDB [(none)]> show variables like 'innodb_log_buffer_size';
+------------------------+----------+
| Variable_name | Value |
+------------------------+----------+
| innodb_log_buffer_size | 17408000 |
+------------------------+----------+
1 row in set (0.001 sec)
MariaDB [(none)]> exit
Bye
As we can see from above the configuration has been changed, the value of max_connections has been changed from 250 to 230 and the read_buffer_size has been changed 122880 to 1064960 also, innodb_log_buffer_size has been changed from 16777216 to 17408000. So the reconfiguration of the sample-mariadb database is successful.
Remove Custom Configuration
We can also remove exisiting custom config using MariaDBOpsRequest. Provide true to field spec.configuration.removeCustomConfig and make an Ops Request to remove existing custom configuration.
Create MariaDBOpsRequest
Lets create an MariaDBOpsRequest having spec.configuration.removeCustomConfig is equal true,
apiVersion: ops.kubedb.com/v1alpha1
kind: MariaDBOpsRequest
metadata:
name: mdops-reconfigure-remove
namespace: demo
spec:
type: Reconfigure
databaseRef:
name: sample-mariadb
configuration:
removeCustomConfig: true
Here,
spec.databaseRef.namespecifies that we are reconfiguringmdops-reconfigure-removedatabase.spec.typespecifies that we are performingReconfigureon our database.spec.configuration.removeCustomConfigis a bool field that should betruewhen you want to remove existing custom configuration.
Let’s create the MariaDBOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2022.12.24-rc.1/docs/guides/mariadb/reconfigure/cluster/examples/reconfigure-remove.yaml
mariadbopsrequest.ops.kubedb.com/mdops-reconfigure-remove created
Verify the new configuration is working
If everything goes well, KubeDB Enterprise operator will update the configSecret of MariaDB object.
Let’s wait for MariaDBOpsRequest to be Successful. Run the following command to watch MariaDBOpsRequest CR,
$ kubectl get mariadbopsrequest --all-namespaces
NAMESPACE NAME TYPE STATUS AGE
demo mdops-reconfigure-remove Reconfigure Successful 2m1s
Now let’s connect to a mariadb instance and run a mariadb internal command to check the new configuration we have provided.
$ kubectl exec -it -n demo sample-mariadb-0 -- bash
root@sample-mariadb-0:/ mysql -u${MYSQL_ROOT_USERNAME} -p${MYSQL_ROOT_PASSWORD}
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 23
Server version: 10.6.4-MariaDB-1:10.6.4+maria~focal mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
# value of `max_conncetions` is default
MariaDB [(none)]> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 151 |
+-----------------+-------+
1 row in set (0.001 sec)
# value of `read_buffer_size` is default
MariaDB [(none)]> show variables like 'read_buffer_size';
+------------------+---------+
| Variable_name | Value |
+------------------+---------+
| read_buffer_size | 131072 |
+------------------+---------+
1 row in set (0.001 sec)
# value of `innodb_log_buffer_size` is default
MariaDB [(none)]> show variables like 'innodb_log_buffer_size';
+------------------------+----------+
| Variable_name | Value |
+------------------------+----------+
| innodb_log_buffer_size | 16777216 |
+------------------------+----------+
1 row in set (0.001 sec)
MariaDB [(none)]> exit
Bye
As we can see from the configuration has changed to its default value. So removal of existing custom configuration using MariaDBOpsRequest is successful.
Cleaning Up
To clean up the Kubernetes resources created by this tutorial, run:
$ kubectl delete mariadb -n demo sample-mariadb
$ kubectl delete mariadbopsrequest -n demo mdops-reconfigure-config mdops-reconfigure-apply-config mdops-reconfigure-remove
$ kubectl delete ns demo