Configure cluster parameters
This guide shows how to configure cluster parameters.
From v0.9.0, KubeBlocks supports dynamic configuration. When the specification of a database instance changes (e.g. a user vertically scales a cluster), KubeBlocks automatically matches the appropriate configuration template based on the new specification. This is because different specifications of a database instance may require different optimal configurations to optimize performance and resource utilization. When you choose a different database instance specification, KubeBlocks automatically detects it and determines the best database configuration for the new specification, ensuring optimal performance and configuration of the database under the new specifications.
This feature simplifies the process of configuring parameters, which saves you from manually configuring database parameters as KubeBlocks handles the updates and configurations automatically to adapt to the new specifications. This saves time and effort and reduces performance issues caused by incorrect configuration.
But it's also important to note that the dynamic parameter configuration doesn't apply to all parameters. Some parameters may require manual configuration. Additionally, if you have manually modified database parameters before, KubeBlocks may overwrite your customized configurations when updating the database configuration template. Therefore, when using the dynamic configuration feature, it is recommended to back up and record your custom configuration so that you can restore them if needed.
View parameter information
View the current configuration file of a cluster.
kbcli cluster describe-config mycluster
From the meta information, the cluster mycluster
has a configuration file named my.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 --show-detail
View the parameter description.
kbcli cluster explain-config mycluster | head -n 20
View the user guide of a specified parameter.
kbcli cluster explain-config mycluster --param=innodb_buffer_pool_size --config-specs=mysql-replication-config
--config-specs
is required to specify a configuration template since MySQL currently supports multiple templates. You can runkbcli cluster describe-config mycluster
to view the all template names.Output
component: mysql
template meta:
ConfigSpec: mysql-replication-config ComponentName: mysql ClusterName: mycluster
Configure Constraint:
Parameter Name: innodb_buffer_pool_size
Allowed Values: [5242880-18446744073709552000]
Scope: Global
Dynamic: true
Type: integer
Description: The size in bytes of the memory buffer innodb uses to cache data and indexes of its tables- Allowed Values: It defines the valid value range of this parameter.
- Dynamic: The value of
Dynamic
inConfigure 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
istrue
, it means the effectiveness type of parameters is dynamic and can be configured online. - When
Dynamic
isfalse
, it means the effectiveness type of parameters is static and a pod restarting is required to make the configuration effective.
- When
- Description: It describes the parameter definition.
Configure parameters
Configure parameters with configure command
The example below takes configuring max_connections
and innodb_buffer_pool_size
as an example.
View the current values of
max_connections
andinnodb_buffer_pool_size
.kbcli cluster connect mycluster
mysql> show variables like '%max_connections%';
>
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 167 |
+-----------------+-------+
1 row in set (0.04 sec)mysql> show variables like '%innodb_buffer_pool_size%';
>
+-------------------------+-----------+
| Variable_name | Value |
+-------------------------+-----------+
| innodb_buffer_pool_size | 134217728 |
+-------------------------+-----------+
1 row in set (0.00 sec)Adjust the values of
max_connections
andinnodb_buffer_pool_size
.kbcli cluster configure mycluster --set=max_connections=600,innodb_buffer_pool_size=512M
noteMake 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 --set=max_connections=200,innodb_buffer_pool_size=2097152
error: failed to validate updated config: [failed to cue template render configure: [mysqld.innodb_buffer_pool_size: invalid value 2097152 (out of bound >=5242880):
343:34
]
]Search the status of the parameter configuration.
Status.Progress
shows the overall status of the parameter configuration andConditions
show the details.kbcli cluster describe-ops mycluster-reconfiguring-pxs46 -n default
Output
Spec:
Name: mycluster-reconfiguring-pxs46 NameSpace: default Cluster: mycluster Type: Reconfiguring
Command:
kbcli cluster configure mycluster --components=mysql --config-specs=mysql-replication-config --config-file=my.cnf --set innodb_buffer_pool_size=512M --set max_connections=600 --namespace=default
Status:
Start Time: Jul 05,2024 19:00 UTC+0800
Completion Time: Jul 05,2024 19:00 UTC+0800
Duration: 2s
Status: Succeed
Progress: 2/2
OBJECT-KEY STATUS DURATION MESSAGE
Conditions:
LAST-TRANSITION-TIME TYPE REASON STATUS MESSAGE
Jul 05,2024 19:00 UTC+0800 WaitForProgressing WaitForProgressing True wait for the controller to process the OpsRequest: mycluster-reconfiguring-pxs46 in Cluster: mycluster
Jul 05,2024 19:00 UTC+0800 Validated ValidateOpsRequestPassed True OpsRequest: mycluster-reconfiguring-pxs46 is validated
Jul 05,2024 19:00 UTC+0800 Reconfigure ReconfigureStarted True Start to reconfigure in Cluster: mycluster, Component: mysql
Jul 05,2024 19:00 UTC+0800 Succeed OpsRequestProcessedSuccessfully True Successfully processed the OpsRequest: mycluster-reconfiguring-pxs46 in Cluster: mycluster
Warning Events: <none>Connect to the database to verify whether the parameters are configured as expected.
The whole searching process has a 30-second delay since it takes some time for kubelet to synchronize modifications to the volume of the pod.
kbcli cluster connect mycluster
mysql> show variables like '%max_connections%';
>
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 600 |
+-----------------+-------+
1 row in set (0.04 sec)mysql> show variables like '%innodb_buffer_pool_size%';
>
+-------------------------+-----------+
| Variable_name | Value |
+-------------------------+-----------+
| innodb_buffer_pool_size | 536870912 |
+-------------------------+-----------+
1 row in set (0.00 sec)
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.
Edit the configuration file.
kbcli cluster edit-config mycluster --config-specs=mysql-replication-config
note- Since MySQL currently supports multiple templates, it is required to use
--config-specs
to specify a configuration template. You can runkbcli cluster describe-config mycluster
to view all template names. - If there are multiple components in a cluster, use
--components
to specify a component.
- Since MySQL currently supports multiple templates, it is required to use
View the status of the parameter configuration.
kbcli cluster describe-ops xxx -n default
Connect to the database to verify whether the parameters are configured as expected.
kbcli cluster connect mycluster
note- For the
edit-config
function, static parameters and dynamic parameters cannot be edited at the same time. - Deleting a parameter will be supported later.
- For the
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
>
component: mysql
ConfigSpecs Meta:
CONFIG-SPEC-NAME FILE ENABLED TEMPLATE CONSTRAINT RENDERED COMPONENT CLUSTER
mysql-replication-config my.cnf true oracle-mysql8.0-config-template oracle-mysql8.0-config-constraints mycluster-mysql-mysql-replication-config mysql mycluster
agamotto-configuration agamotto-config.yaml false mysql-agamotto-configuration mycluster-mysql-agamotto-configuration mysql mycluster
agamotto-configuration agamotto-config-with-proxy.yaml false mysql-agamotto-configuration mycluster-mysql-agamotto-configuration mysql mycluster
History modifications:
OPS-NAME CLUSTER COMPONENT CONFIG-SPEC-NAME FILE STATUS POLICY PROGRESS CREATED-TIME VALID-UPDATED
mycluster-reconfiguring-pxs46 mycluster mysql mysql-replication-config my.cnf Succeed syncDynamicReload 2/2 Jul 05,2024 19:00 UTC+0800 {"my.cnf":"{\"mysqld\":{\"innodb_buffer_pool_size\":\"512M\",\"max_connections\":\"600\"}}"}
mycluster-reconfiguring-x52fb mycluster mysql mysql-replication-config my.cnf Succeed syncDynamicReload 2/2 Jul 05,2024 19:04 UTC+0800 {"my.cnf":"{\"mysqld\":{\"max_connections\":\"1000\"}}"}
From the above results, there are two parameter modifications.
Compare these modifications to view the configured parameters and their different values for different versions.
kbcli cluster diff-config mycluster-reconfiguring-pxs46 mycluster-reconfiguring-x9zsf
>
DIFF-CONFIGURE RESULT:
ConfigFile: my.cnf TemplateName: mysql-replication-config ComponentName: mysql ClusterName: mycluster UpdateType: update
PARAMETERNAME mycluster-reconfiguring-pxs46 mycluster-reconfiguring-x9zsf
max_connections 600 2000
innodb_buffer_pool_size 512M 1G