Configure cluster parameters

The KubeBlocks configuration function provides a set of consistent default configuration generation strategies for all the databases running on KubeBlocks and also provides a unified parameter configuration interface to facilitate managing parameter configuration, searching the parameter user guide, and validating parameter effectiveness.

From v0.6.0, KubeBlocks supports kbcli cluster configure and kbcli cluster edit-config to configure parameters. The difference is that KubeBlocks configures parameters automatically with kbcli cluster configure but kbcli cluster edit-config provides a visualized way for you to edit parameters directly.

KubeBlocks also supports configuring a cluster by editing the configuration file or applying an OpsRequest.

Edit config file

KubeBlocks supports configuring cluster parameters by editing its configuration file.

1. Get the configuration file of this cluster.

   kubectl get configurations.apps.kubeblocks.io -n demo
   
   kubectl edit configurations.apps.kubeblocks.io mycluster-kafka-combine -n demo

2. Configure parameters according to your needs. The example below adds the spec.configFileParams part to configure log.cleanup.policy.

   spec:
     clusterRef: mycluster
     componentName: kafka
     configItemDetails:
     - configFileParams:
         server.properties:
           parameters:
             log.cleanup.policy: "compact"
       configSpec:
         constraintRef: kafka-cc
         name: kafka-configuration-tpl
         namespace: kb-system
         templateRef: kafka-configuration-tpl
         volumeName: kafka-config
       name: kafka-configuration-tpl

3. Connect to this cluster to verify whether the configuration takes effect as expected.

   kbcli cluster describe-config mycluster -n demo --show-detail | grep log.cleanup.policy
   >
   log.cleanup.policy = compact

note

Just in case you cannot find the configuration file of your cluster, you can switch to the kbcli tab to view the current configuration file of a cluster.

OpsRequest

KubeBlocks supports configuring cluster parameters with OpsRequest.

1. Define an OpsRequest file and configure the parameters in the OpsRequest in a yaml file named mycluster-configuring-demo.yaml. In this example, log.cleanup.policy is configured as compact.

   apiVersion: apps.kubeblocks.io/v1alpha1
   kind: OpsRequest
   metadata:
     name: mycluster-configuring-demo
     namespace: demo
   spec:
     clusterName: mycluster
     reconfigure:
       componentName: kafka
       configurations:
       - keys:
         - key: server.properties
           parameters:
           - key: log.cleanup.policy
             value: "compact"
         name: kafka-configuration-tpl
     preConditionDeadlineSeconds: 0
     type: Reconfiguring
   EOF

   Field	Definition
   metadata.name	It specifies the name of this OpsRequest.
   metadata.namespace	It specifies the namespace where this cluster is created.
   spec.clusterName	It specifies the cluster name that this operation is targeted at.
   spec.reconfigure	It specifies a component and its configuration updates.
   spec.reconfigure.componentName	It specifies the component name of this cluster.
   spec.configurations	It contains a list of ConfigurationItem objects, specifying the component's configuration template name, upgrade policy, and parameter key-value pairs to be updated.
   spec.reconfigure.configurations.keys.key	It specifies the configuration map.
   spec.reconfigure.configurations.keys.parameters	It defines a list of key-value pairs for a single configuration file.
   spec.reconfigure.configurations.keys.parameter.key	It represents the name of the parameter you want to edit.
   spec.reconfigure.configurations.keys.parameter.value	It represents the parameter values that are to be updated. If set to nil, the parameter defined by the Key field will be removed from the configuration file.
   spec.reconfigure.configurations.name	It specifies the configuration template name.
   preConditionDeadlineSeconds	It specifies the maximum number of seconds this OpsRequest will wait for its start conditions to be met before aborting. If set to 0 (default), the start conditions must be met immediately for the OpsRequest to proceed.

2. Apply the configuration opsRequest.

   kubectl apply -f mycluster-configuring-demo.yaml

3. Verify whether the configuration takes effect as expected.

   kbcli cluster describe-config mycluster -n demo --show-detail | grep log.cleanup.policy
   >
   log.cleanup.policy = compact

note

Just in case you cannot find the configuration file of your cluster, you can switch to the kbcli tab to view the current configuration file of a cluster.

kbcli

View parameter information

View the current configuration file of a cluster.

kbcli cluster describe-config mycluster -n demo

From the meta information, the cluster mycluster has a configuration file named server.properties.

You can also view the details of this configuration file and parameters.

• View the details of the current configuration file.

  kbcli cluster describe-config mycluster -n demo --show-detail

• View the parameter description.

  kbcli cluster explain-config mycluster -n demo | head -n 20

• View the user guide of a specified parameter.

  kbcli cluster explain-config mycluster -n demo --param=log.cleanup.policy
  Output

  template meta:
    ConfigSpec: kafka-configuration-tpl	ComponentName: broker	ClusterName: mycluster
  
  Configure Constraint:
    Parameter Name:     log.cleanup.policy
    Allowed Values:     "compact","delete"
    Scope:              Global
    Dynamic:            false
    Type:               string
    Description:        The default cleanup policy for segments beyond the retention window. A comma separated list of valid policies. 
  • Allowed Values: It defines the valid value range of this parameter.
  • Dynamic: The value of Dynamic in Configure Constraint defines how the parameter configuration takes effect. Currently, Kafka only supports static strategy, i.e. Dynamic is false. Restarting is required to make the configuration effective.
  • Description: It describes the parameter definition.

Configure parameters

Configure parameters with configure command

1. View the current value of log.cleanup.policy.

   kbcli cluster describe-config mycluster -n demo --show-detail | grep log.cleanup.policy
   >
   log.cleanup.policy=delete

2. Adjust the value of log.cleanup.policy.

   kbcli cluster configure mycluster -n demo --set=log.cleanup.policy=compact
   note

   Make sure the value you set is within the Allowed Values of this parameter. Otherwise, the configuration may fail.

3. View the status of the parameter configuration.

   Status.Progress and Status.Status shows the overall status of the parameter configuration and Conditions show the details.

   When the Status.Status shows Succeed, the configuration is completed.

   Output

   # In progress
   kbcli cluster describe-ops mycluster-reconfiguring-wvqns -n default
   >
   Spec:
     Name: mycluster-reconfiguring-wvqns	NameSpace: default	Cluster: mycluster	Type: Reconfiguring
   
   Command:
     kbcli cluster configure mycluster -n demo --components=broker --config-specs=kafka-configuration-tpl --config-file=server.properties --set log.cleanup.policy=compact --namespace=default
   
   Status:
     Start Time:         Sep 14,2023 16:28 UTC+0800
     Duration:           5s
     Status:             Running
     Progress:           0/1
                         OBJECT-KEY   STATUS   DURATION   MESSAGE

   # Parameter reconfiguration is completed
   kbcli cluster describe-ops mycluster-reconfiguring-wvqns -n demo
   >
   Spec:
     Name: mycluster-reconfiguring-wvqns	NameSpace: default	Cluster: mycluster	Type: Reconfiguring
   
   Command:
     kbcli cluster configure mycluster -n demo --components=broker --config-specs=kafka-configuration-tpl --config-file=server.properties --set log.cleanup.policy=compact --namespace=default
   
   Status:
     Start Time:         Sep 14,2023 16:28 UTC+0800
     Completion Time:    Sep 14,2023 16:28 UTC+0800
     Duration:           25s
     Status:             Succeed
     Progress:           1/1
                         OBJECT-KEY   STATUS   DURATION   MESSAGE

4. View the configuration file to verify whether the parameter is configured as expected.

   It takes about 30 seconds for the configuration to take effect because the kubelet requires some time to sync changes in the ConfigMap to the Pod's volume.

   kbcli cluster describe-config mycluster -n demo --show-detail | grep log.cleanup.policy
   >
   log.cleanup.policy = compact
   mycluster-reconfiguring-wvqns   mycluster   broker      kafka-configuration-tpl   server.properties   Succeed   restart   1/1        Sep 14,2023 16:28 UTC+0800   {"server.properties":"{\"log.cleanup.policy\":\"compact\"}"}

Configure parameters with edit-config command

For your convenience, KubeBlocks offers a tool edit-config to help you to configure parameter in a visualized way.

For Linux and macOS, you can edit configuration files by vi. For Windows, you can edit files on notepad.

1. Edit the configuration file.

   kbcli cluster edit-config mycluster -n demo
   note

   If there are multiple components in a cluster, use --components to specify a component.

2. View the status of the parameter configuration.

   kbcli cluster describe-ops xxx -n default

3. Connect to the database to verify whether the parameters are configured as expected.

   kbcli cluster connect mycluster -n demo
   note

   1. For the edit-config function, static parameters and dynamic parameters cannot be edited at the same time.
   2. Deleting a parameter will be supported later.

View history and compare differences

After the configuration is completed, you can search the configuration history and compare the parameter differences.

View the parameter configuration history.

kbcli cluster describe-config mycluster -n demo                 

From the above results, there are three parameter modifications.

Compare these modifications to view the configured parameters and their different values for different versions.

kbcli cluster diff-config mycluster-reconfiguring-wvqns mycluster-reconfiguring-hxqfx -n demo
>
DIFF-CONFIG RESULT:
  ConfigFile: server.properties	TemplateName: kafka-configuration-tpl	ComponentName: broker	ClusterName: mycluster	UpdateType: update

PARAMETERNAME         MYCLUSTER-RECONFIGURING-WVQNS   MYCLUSTER-RECONFIGURING-HXQFX
log.retention.hours   168                             200