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KubeBlocks for Redis

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Configuration

Configure cluster parameters

High Availability

High Availability for Redis
Redis Cluster Mode
  1. View parameter information
  2. Configure parameters
    1. Configure parameters with configure command
    2. Configure parameters with edit-config command
  3. View history and compare differences

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.

  1. Get the configuration file of this cluster.

    kubectl edit configurations.apps.kubeblocks.io mycluster-redis -n demo
  2. Configure parameters according to your needs. The example below adds the - configFileParams part to configure acllog-max-len.

    spec: clusterRef: mycluster componentName: redis configItemDetails: - configSpec: constraintRef: redis7-config-constraints name: redis-replication-config namespace: demo reRenderResourceTypes: - vscale templateRef: redis7-config-template volumeName: redis-config - configFileParams: redis.conf: parameters: acllog-max-len: "256" name: mycluster-redis-redis-replication-config
  3. Connect to this cluster to verify whether the configuration takes effect.

    1. Get the username and password.

      kubectl get secrets -n demo mycluster-conn-credential -o jsonpath='{.data.username}' | base64 -d > default kubectl get secrets -n demo mycluster-conn-credential -o jsonpath='{.data.password}' | base64 -d > kpz77mcs
    2. Connect to this cluster and verify whether the parameters are configured as expected.

      kubectl exec -ti -n demo mycluster-redis-0 -- bash root@mycluster-redis-0:/# redis-cli -a kpz77mcs --user default 127.0.0.1:6379> config get parameter acllog-max-len 1) "acllog-max-len" 2) "256"
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.

  1. Define an OpsRequest file and configure the parameters in the OpsRequest in a yaml file named mycluster-configuring-demo.yaml. In this example, acllog-max-len is configured as 256.

    apiVersion: apps.kubeblocks.io/v1alpha1 kind: OpsRequest metadata: name: mycluster-configuring-demo namespace: demo spec: clusterName: mycluster reconfigure: componentName: redis configurations: - keys: - key: redis.conf parameters: - key: acllog-max-len value: "256" name: redis-replication-config preConditionDeadlineSeconds: 0 type: Reconfiguring
    FieldDefinition
    metadata.nameIt specifies the name of this OpsRequest.
    metadata.namespaceIt specifies the namespace where this cluster is created.
    spec.clusterNameIt specifies the cluster name that this operation is targeted at.
    spec.reconfigureIt specifies a component and its configuration updates.
    spec.reconfigure.componentNameIt specifies the component name of this cluster.
    spec.configurationsIt 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.keyIt specifies the configuration map.
    spec.reconfigure.configurations.keys.parametersIt defines a list of key-value pairs for a single configuration file.
    spec.reconfigure.configurations.keys.parameter.keyIt represents the name of the parameter you want to edit.
    spec.reconfigure.configurations.keys.parameter.valueIt 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.nameIt specifies the configuration template name.
    preConditionDeadlineSecondsIt 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. Connect to this cluster to verify whether the configuration takes effect.

    1. Get the username and password.

      kubectl get secrets -n demo mycluster-conn-credential -o jsonpath='{.data.username}' | base64 -d > default kubectl get secrets -n demo mycluster-conn-credential -o jsonpath='{.data.password}' | base64 -d > kpz77mcs
    2. Connect to this cluster and verify whether the parameters are configured as expected.

      kubectl exec -ti -n demo mycluster-redis-0 -- bash root@mycluster-redis-0:/# redis-cli -a kpz77mcs --user default 127.0.0.1:6379> config get parameter acllog-max-len 1) "acllog-max-len" 2) "256"
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.

View parameter information

View the current configuration file of a cluster.

kbcli cluster describe-config mycluster --components=redis -n demo

From the meta information, the cluster mycluster has a configuration file named redis.cnf.

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 --components=redis --show-detail
  • View the parameter description.

    kbcli cluster explain-config mycluster -n demo --components=redis |head -n 20
  • View the user guide of a specified parameter.

    kbcli cluster explain-config mycluster -n demo --components=redis --param=acllog-max-len
    Output
    template meta: ConfigSpec: redis-replication-config ComponentName: redis ClusterName: mycluster -n demo Configure Constraint: Parameter Name: acllog-max-len Allowed Values: [1-10000] Scope: Global Dynamic: true Type: integer Description:
    • 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. There are two different configuration strategies based on the effectiveness type of modified parameters, i.e. dynamic and static.
      • When Dynamic is true, it means the effectiveness type of parameters is dynamic and can be updated online.
      • When Dynamic is false, it means the effectiveness type of parameters is static and a pod restarting is required to make the configuration effective.
    • Description: It describes the parameter definition.

Configure parameters

Configure parameters with configure command

The example below configures acllog-max-len.

  1. View the current values of acllog-max-len.

    kbcli cluster connect mycluster -n demo
    127.0.0.1:6379> config get parameter acllog-max-len 1) "acllog-max-len" 2) "128"
  2. Adjust the values of acllog-max-len.

    kbcli cluster configure mycluster -n demo --components=redis --set=acllog-max-len=256
    NOTE

    Make sure the value you set is within the Allowed Values of this parameter. If you set a value that does not meet the value range, the system prompts an error. For example,

    kbcli cluster configure mycluster -n demo --set=acllog-max-len=1000000 > error: failed to validate updated config: [failed to cue template render configure: [configuration."acllog-max-len": 2 errors in empty disjunction: configuration."acllog-max-len": conflicting values 128 and 1000000: 20:43 155:16 configuration."acllog-max-len": invalid value 1000000 (out of bound <=10000): 20:32 ] ]
  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.

    kbcli cluster describe-ops mycluster-reconfiguring-zjztm -n demo
    Output
    Spec: Name: mycluster-reconfiguring-zjztm NameSpace: demo Cluster: mycluster Type: Reconfiguring Command: kbcli cluster configure mycluster -n demo --components=redis --config-specs=redis-replication-config --config-file=redis.conf --set acllog-max-len=256 --namespace=demo Status: Start Time: Sep 29,2024 10:46 UTC+0800 Duration: 10s Status: Running Progress: 1/2 OBJECT-KEY STATUS DURATION MESSAGE Conditions: LAST-TRANSITION-TIME TYPE REASON STATUS MESSAGE Sep 29,2024 10:46 UTC+0800 Progressing Progressing True wait for the controller to process the OpsRequest: mycluster-reconfiguring-zjztm in Cluster: mycluster Sep 29,2024 10:46 UTC+0800 Validated ValidateOpsRequestPassed True OpsRequest: mycluster-reconfiguring-zjztm is validated Sep 29,2024 10:46 UTC+0800 Reconfigure ReconfigureStarted True Start to reconfigure in Cluster: mycluster, Component: redis
  4. Connect to the database 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 connect mycluster -n demo
    127.0.0.1:6379> config get parameter acllog-max-len 1) "acllog-max-len" 2) "256"

Configure parameters with edit-config command

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

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

  1. Edit the configuration file.

    kbcli cluster edit-config mycluster -n demo
    NOTE

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

  2. View the status of the parameter configuration.

    kbcli cluster describe-ops mycluster-reconfiguring-nflq8 -n demo
  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 --components=redis
Output
ConfigSpecs Meta: CONFIG-SPEC-NAME FILE ENABLED TEMPLATE CONSTRAINT RENDERED COMPONENT CLUSTER redis-replication-config redis.conf true redis7-config-template redis7-config-constraints mycluster-redis-redis-replication-config redis mycluster History modifications: OPS-NAME CLUSTER COMPONENT CONFIG-SPEC-NAME FILE STATUS POLICY PROGRESS CREATED-TIME VALID-UPDATED mycluster-reconfiguring-zjztm mycluster redis redis-replication-config redis.conf Succeed restart 1/1 Sep 29,2024 10:46 UTC+0800 mycluster-reconfiguring-zrkq7 mycluster redis redis-replication-config redis.conf Succeed restart 1/1 Sep 29,2024 11:08 UTC+0800 {"redis.conf":"{\"databases\":\"32\",\"maxclients\":\"20000\"}"} mycluster-reconfiguring-mwbnw mycluster redis redis-replication-config redis.conf Succeed restart 1/1 Sep 29,2024 11:20 UTC+0800 {"redis.conf":"{\"maxclients\":\"40000\"}"}

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-zrkq7 mycluster-reconfiguring-mwbnw > DIFF-CONFIG RESULT: ConfigFile: redis.conf TemplateName: redis-replication-config ComponentName: redis ClusterName: mycluster UpdateType: update PARAMETERNAME MYCLUSTER-RECONFIGURING-ZRKQ7 MYCLUSTER-RECONFIGURING-MWBNW maxclients 20000 40000

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