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.

kbcli

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

Edit config file

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.

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, 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

   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. 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.