Performing Rolling Restart

Restrictions

• Perform a rolling restart during off-peak hours.
  • Otherwise, a rolling restart failure may occur. For example, if the throughput of Kafka is high (over 100 MB/s) during the Kafka rolling restart, the Kafka rolling restart may fail.
  • For example, if the requests per second of each RegionServer on the native interface exceed 10,000 during the HBase rolling restart, you need to increase the number of handles to prevent a RegionServer restart failure caused by heavy loads during the restart.
• Before the restart, check the number of current requests of HBase. If the number of requests of each RegionServer on the native interface exceeds 10,000, increase the number of handles to prevent a failure.
• If the number of Core nodes in a cluster is less than six, services may be affected for a short period of time.
• Preferentially perform a rolling instance or service restart and select Only restart instances whose configurations have expired.

Performing a Rolling Service Restart

1. Choose Clusters > Active Clusters and click a cluster name to go to the cluster details page.
2. Click Components and select a service for which you want to perform a rolling restart.
3. On the Service Status tab page, click More and select Rolling-restart Service.
   Figure 1 Service status (MRS 1.9.2 is used as an example)
   

4. The Rolling-restart Service page is displayed. Select Only restart instances whose configurations have expired and click OK to perform rolling restart for the service.
   Figure 2 Performing a rolling service restart
   

5. After the rolling restart task is complete, click Finish.
   Figure 3 Finishing the rolling service restart
   

Performing a Rolling Instance Restart

1. Choose Clusters > Active Clusters and click a cluster name to go to the cluster details page.
2. Click Components and select a service for which you want to perform a rolling restart.
3. On the Instance tab page, select the instance to be restarted. Click More and select Rolling-restart Instance.
   Figure 4 Performing a rolling instance restart
   

4. After you enter the administrator password, the Rolling-restart Instance page is displayed. Select Only restart instances whose configurations have expired and click OK to perform rolling restart for the instance.
5. After the rolling restart task is complete, click Finish.

Perform a Rolling Cluster Restart

1. Choose Clusters > Active Clusters and click a cluster name to go to the cluster details page.
2. In the upper right corner of the page, choose Management Operations > Perform Rolling Cluster Restart.
   Figure 5 Performing a Rolling Restart of a Cluster (Using MRS 1.9.2 as an Example)
   

3. The Rolling-restart Cluster page is displayed. Select Only restart instances whose configurations have expired and click OK to perform rolling restart for the cluster.
4. After the rolling restart task is complete, click Finish.

Rolling Restart Parameter Description

Table 2 describes rolling restart parameters.

Procedure in a Typical Scenario

1. Choose Clusters > Active Clusters and click a cluster name to go to the cluster details page.
2. Click Components and select HBase. The HBase service page is displayed.
3. Click the Service Configuration tab, modify an HBase parameter, and save the configuration as prompted.
   

   In versions earlier than MRS 3.x, do not select Restart the affected services or instances. This option indicates a normal restart. If you select this option, all services or instances will be restarted, which may cause service interruption.

4. After saving the configurations, click Finish.
5. Click the Service Status tab.
6. On the Service Status tab page, click More and select Rolling-restart Service.
   Figure 6 Service status - rolling restart (using MRS 1.9.2 as an example)
   

7. After you enter the administrator password, the Rolling-restart Service page is displayed. Select Only restart instances whose configurations have expired and click OK to perform rolling restart.
   Figure 7 Configuring the rolling service restart
   

8. After the rolling restart task is complete, click Finish.
   Figure 8 Finishing the rolling service restart