Modifying MRS Role Instance Parameters
Administrators may need to adjust configuration parameters for individual role instances while an MRS cluster is running to optimize performance or adapt to changing workload demands. For example, administrators can export and import configuration data to replicate settings during cluster migrations or service redeployments. Modifying, exporting, or importing instance configurations does not affect other running instances.
Impact on the System
- After modifying the configuration of a role instance, you need to restart the instance if the instance status is Expired. The instance will be unavailable during the restart. Perform this operation during off-peak hours.
- You need to download and update the client configuration files after configuring HBase, HDFS, Hive, Spark, YARN, and MapReduce service properties. For details about updating client configurations, see Updating the MRS Cluster Client After the Server Configuration Expires.
Prerequisites
- The IAM users have been synchronized in advance. You can do this by clicking Synchronize next to IAM User Sync on the Dashboard page of the cluster details.
- You have logged in to MRS Manager. For how to log in, see Accessing MRS Manager.
Modifying Role Instance Parameters
You can modify parameters on either the management console or MRS Manager.
- Log in to the MRS console.
- Click the target cluster name.
- On the MRS cluster details page, click Components.
- Select the target service from the service list.
- Click the Instances tab.
- Click the target role instance from the role instance list.
- Click the Instance Configuration tab.
- Switch Basic to All from the drop-down list on the right of the page. All configuration parameters of the role instance are displayed in the navigation tree.
- In the navigation tree, select a specified parameter and change its value. You can also enter the parameter name in the Search box to search for the parameter and view the result.
If you want to cancel the modification of a parameter value, click
to restore it. - Click Save Configuration and operate as prompted.
After the configuration parameters of a role instance are modified, you need to restart the instance if the instance status is Configuration expired. You can select the instances whose configurations have expired on the Instances tab page, and choose More > Restart Instance.
Verifying the configuration changes:
- After saving the configuration, verify that a message appears indicating that the operation is successful.
- Check the instance status. If the status is Configuration expired, restart the instance for the new settings to take effect. If the parameter takes effect dynamically, verify that it has updated automatically.
- After the restart completes, verify that the instance status is normal on the instance list page.
- Log in to FusionInsight Manager of the MRS cluster.
For details about how to log in to FusionInsight Manager, see Accessing MRS Manager.
- Choose Cluster > Services.
For MRS 2.x and earlier versions, click Services.
- Click the specified service name and click Instances.
- Click the specified instance and select Instance Configuration.
By default, Basic Configuration is displayed. To modify more parameters, click All Configurations. All parameter categories supported by the instance are displayed on the All Configurations page.
- In the navigation tree, select the specified parameter category and change the parameter values on the right.
Enter the name of a parameter in the upper right corner to search for it. Search results are displayed on Manager in real-time.
- Click Save. In the confirmation dialog box, click OK.
For MRS 2.x and earlier versions, click Save Configuration, select Restart the role instance, and click OK to restart the role instance.
Wait until the message "Operation succeeded" is displayed. Click Finish. The configuration is modified.
- After the configuration parameters of a role instance are modified, you need to restart the instance if the instance status is Expired. You can select the instances whose configurations have expired on the Instances tab page, and choose More > Restart Instance.
- If
is displayed before a parameter, this parameter takes effect dynamically. After the configuration is saved, the parameter value is automatically updated to the configuration file. 
is supported only in MRS 3.2.0 or later.
Verifying the configuration changes:
- After saving the configuration, verify that a message appears indicating that the operation is successful.
- Check the instance status. If the status is Configuration expired, restart the instance for the new settings to take effect. If the parameter takes effect dynamically, verify that it has updated automatically.
- After the restart completes, verify that the instance status is normal on the instance list page.
FAQs
- What should I do if the instance status is Configuration expired after parameter changes?
This is expected behavior. If you modify a parameter that does not take effect dynamically, the instance status changes to Configuration expired. You must restart the instance for the new configuration to take effect.
- How do I restore the original values of modified parameters?
Before saving the configuration, click the undo icon next to the parameter text box to restore the previous value. If you have already saved the configuration, manually change the parameter back to its previous value and save the configuration again.
- Which parameters do not require an instance restart after modification?
Parameters marked with a dynamic parameter icon are dynamic parameters. After you save the configuration, these parameters update automatically in the configuration file without requiring an instance restart. This feature is supported in MRS 3.2.0 or later. If a parameter lacks this icon, you must restart the instance for the changes to take effect.
Helpful Links
- For details about how to export and import role instance configurations, see Managing MRS Role Instances.
- For details about how to update the client configuration file, see Updating the MRS Cluster Client After the Server Configuration Expires.
