This topic describes how to modify the global parameters in the config.xml configuration file of an ApsaraDB for ClickHouse cluster.
Background information
An ApsaraDB for ClickHouse cluster has several parameters. The default values for these parameters are typically configured in the config.xml and user.xml files. You can modify the parameters to optimize the instance. The files are used for different purposes:
user.xml configuration file: You can use the
SET GLOBALcommand to modify parameter values. These changes take effect without requiring a restart. For more information, see Modify user.xml parameters.config.xml configuration file: You can modify parameter values in the console. For instructions, see the procedure in this topic.
Precautions
The features for configuring parameters in XML mode and viewing modification history are supported only on Community Edition clusters created after December 1, 2021.
Enterprise Edition clusters do not support configuring parameters in XML mode.
You cannot delete parameters in XML mode. The parameters that can be configured in XML mode are the same as those in default mode.
If any modified parameters require a restart to take effect, the cluster automatically restarts after you submit the changes. Before you submit the parameters, confirm that a cluster restart will not affect your services.
Impact on the cluster
When the cluster is in the Changing Configuration or Restarting state, you can only view cluster information. You cannot perform operations such as upgrades, scale-outs, or scale-ins.
If any modified parameters require a restart to take effect, the cluster automatically restarts after the changes are submitted. We recommend that you perform this operation during off-peak hours to avoid service disruptions.
Modify parameters
The procedure for modifying parameters differs depending on the cluster edition.
For information about modifying the prometheus.port or text_log parameters, see Important parameters.
Enterprise Edition
Log on to the ApsaraDB for ClickHouse console.
In the upper-left corner of the page, select the region where the cluster is located.
On the Clusters page, click the Enterprise Edition Clusters tab, and then click the ID of the cluster.
In the navigation pane on the left, click Parameter Management.
In the Parameter Value column, click the edit icon
. Enter a new value within the specified range, and then click OK.After you modify the parameters, click Submit Parameters in the upper-right corner of the page.
In the Save Settings dialog box, review the changes to the parameter values. Then, enter a reason for the change and click OK.
ImportantIf any submitted parameters require a restart to take effect, ClickHouse automatically restarts the cluster. Confirm that a cluster restart will not affect your services.
After you submit the parameters, the system automatically validates the parameter values. If a parameter value is invalid, an Error message appears. If the ErrorCode is 102, the value is invalid. Return to the previous step, enter a value that is within the specified Input Range, and submit the parameters again.
Community Edition
Log on to the ApsaraDB for ClickHouse console.
In the upper-left corner of the page, select the region where the cluster is located.
On the Clusters page, click the Clusters of Community-compatible Edition tab, and then click the ID of the cluster.
In the navigation pane on the left, click Parameter Configuration.
On the Parameter Configuration page, click the Settings tab. Select Default Mode or XML Mode and modify the parameters.
ImportantThe value range of the prometheus.port parameter is restricted in the ApsaraDB for ClickHouse console. You can only enter a port number from 2182 to 3000.
Default mode: In the Parameter Value column, click the edit icon
. Enter a new value within the specified range, and then click OK.XML mode: In the upper-right corner of the page, click Modify and modify the parameters.
(Optional) In the upper-right corner of the page, select Show Modified Parameters Only to display only the parameters that you have modified but not yet submitted.
After you modify the parameters, click Submit Parameters in the upper-right corner of the page.
In the Save Settings dialog box, review the changes to the parameter values. Then, enter a reason for the change and click Submit Parameters.
ImportantIf any submitted parameters require a restart to take effect, ClickHouse automatically restarts the cluster. Confirm that a cluster restart will not affect your services.
In XML mode, if a parameter value is invalid, an Error message appears. If the ErrorCode is 102, the value is invalid. Return to the previous step, enter a value that is within the specified Input Range, and submit the parameters again.
Revert changes
You can revert changes only for modified parameters that have not been submitted.
For Community Edition clusters in XML Mode and for Enterprise Edition clusters, you can only revert all changes at once.
To revert changes after modifying parameters, perform the following operations before you submit the parameters:
To revert a change to a single parameter, click the
icon next to the parameter value. ApsaraDB for ClickHouse reverts the unsubmitted change, restoring the parameter to its previous value.To revert all parameter changes, click Cancel in the upper-right corner of the parameter list. ApsaraDB for ClickHouse reverts all modified parameters that have not been submitted to their previous values.
View modification history
Enterprise Edition
Log on to the ApsaraDB for ClickHouse console.
In the upper-left corner of the page, select the region where the cluster is located.
On the Clusters page, click the Enterprise Edition Clusters tab, and then click the ID of the cluster.
In the navigation pane on the left, click Parameter Management.
On the Parameter Management page, click the Change History tab. View the modification history in one of the following ways:
Click Last 30 Days or Last 7 Days to view the modification history for the last 30 or 7 days.
Select a start time and an end time to view the modification history for a specific time range.
Community Edition
Log on to the ApsaraDB for ClickHouse console.
In the upper-left corner of the page, select the region where the cluster is located.
On the Clusters page, click the Clusters of Community-compatible Edition tab, and then click the ID of the cluster.
In the navigation pane on the left, click Parameter Configuration.
On the Parameter Configuration page, click the Change History tab. View the modification history in one of the following ways:
Click Last 30 Days or Last 7 Days to view the modification history for the last 30 or 7 days.
Select a start time and an end time, and then click Query to view the modification history for a specific time range.
Important parameters
The value range of the prometheus.port parameter is restricted in the ApsaraDB for ClickHouse console. You can only enter a port number from 2182 to 3000.
In some cluster versions, text_log is not enabled by default or the text_log.level is set too low. To view the text log, you must set the text_log.level parameter to the appropriate level:
Parameter value
Description
Scenarios
trace
The most detailed log level. It records all operations and events.
Trace the execution flow of a program during development and debugging.
debug
It contains detailed information that may be needed during development, but is less verbose than the trace level. It usually records information such as function calls and variable statuses.
Debug a program.
information
Used to record normal system operations and status information, such as starting a service or completing a task. This information usually indicates that the system is running normally without errors.
N/A
warning
Indicates potential issues or non-fatal errors. Although the system is still running, there may be situations that require attention.
Monitor the system, analyze potential issues, and optimize the system.
error
Indicates that an error has occurred in the system, which has affected some system features or operations. Although the system may still be running, these errors need to be addressed promptly.
Monitor the system and analyze errors to help resolve issues.