Scaling Out an MRS Cluster

Constraints

• When you expand a node group where HBase is installed:

  If automatic DNS registration is not enabled for a node in the cluster, do not start HBase when you expand the node group. Then, update the HBase client configuration by referring to Updating the MRS Cluster Client After the Server Configuration Expires and start the HBase instances on the node to be expanded.

  Automatic DNS registration is enabled by default in the following versions:

  MRS 1.9.3, MRS 3.1.0, MRS 3.1.2-LTS, MRS 3.1.5, and MRS 3.2.0-LTS

  You can check whether this DNS function is supported by checking whether the features field in the response body contains register_dns_server For details, see Querying the Metadata of a Cluster Version.

• After a scale-out, the clients installed on nodes in the cluster do not need to be updated. For details about how to update the client installed on nodes outside the cluster, see Updating the MRS Cluster Client After the Server Configuration Expires.
• If you need to balance HDFS data after scale-out, see Balancing DataNode Capacity. For details about how to balance Kafka data, see Kafka Balancing Tool Instructions.

Scaling Out a Cluster Billed in Pay-per-Use Mode

1. Log in to the MRS console.
2. Choose Active Clusters, select a running cluster, and click its name to switch to the cluster details page.
3. Click the Nodes tab. In the Operation column of the node group, click Scale Out. The Scale Out page is displayed.

   The scale-out operation can only be performed on the running clusters.

4. Set the type of System Disk and Data Disk, Scale-Out Nodes, Enable Components and Run Bootstrap Action, and click OK. The Enable Components and Run Bootstrap Action parameters may not be supported by clusters of some versions. The operations are subject to the UI.

   

   

   • If the Task node group does not exist in the cluster, configure the Task node by referring to Related Tasks.
   • If a bootstrap action is added during cluster creation, the Run Bootstrap Action parameter is valid. If this function is enabled, the bootstrap actions added during cluster creation will be run on all the scaled out nodes.
   • If the New Specifications parameter is available, the specifications that are the same as those of the original nodes have been sold out or discontinued. Nodes with new specifications will be added.
   • Before scaling out the cluster, check whether its security group configuration is correct. Ensure that an inbound security group rule contains a rule in which Protocol & Port is set to All, and Source is set to a trusted accessible IP address range.

5. In the Add Node dialog box, click OK.
6. A dialog box is displayed in the upper right corner of the page, indicating that the scale-out task is submitted successfully.
   The following parameters explain the cluster scale-out process:

   • During scale-out: If a cluster is being scaled out, its status is Scaling out. The submitted jobs will be executed and you can submit new jobs. You are not allowed to continue to scale out or delete the cluster. You are advised not to restart the cluster or modify the cluster configuration.
   • Successful scale-out: The cluster status is Running. The resources used in the old nodes and expanded nodes are charged.
   • Failed scale-out: The cluster status is Running. You can execute jobs and scale out the cluster again.

   After the cluster is scaled out, you can view the node information of the cluster on the Nodes page.

Scaling Out a Cluster Billed in Yearly/Monthly Mode

1. Log in to the MRS console.
2. Choose Active Clusters, select a running cluster, and click its name to switch to the cluster details page.
3. Click the Nodes tab. In the Operation column of the node group, click Scale Out. The Scale Out page is displayed.

   The scale-out operation can only be performed on the running clusters.

4. Set the type of the System Disk and Data Disk, Scale-Out Nodes, Enable Components and Run Bootstrap Action. The system displays the expiration time of the cluster and the fee required for adding nodes. Enable Components and Run Bootstrap Action may not be supported by clusters of some versions. The operations are subject to the UI.
   

   • If a bootstrap action is added during cluster creation, the Run Bootstrap Action parameter is valid. If this function is enabled, the bootstrap actions added during cluster creation will be run on all the scaled out nodes.
   • If the New Specifications parameter is available, the specifications that are the same as those of the original nodes have been sold out or discontinued. Nodes with new specifications will be added.
   • Before scaling out the cluster, check whether its security group configuration is correct. Ensure that an inbound security group rule contains a rule in which Protocol & Port is set to All, and Source is set to a trusted accessible IP address range.
   • Click Submit Order.

     On the Purchase MapReduce Service page, click Pay.

   • Click Confirm order, not pay.

     On the cluster information page, choose Fee > My Order and click Pay.

5. After the payment is successful, return to the MRS management console to view the cluster status.
   The following parameters explain the cluster scale-out process:

   • During scale-out: If a cluster is being scaled out, its status is Scaling out. The submitted jobs will be executed and you can submit new jobs. You are not allowed to continue to scale out or delete the cluster. You are advised not to restart the cluster or modify the cluster configuration.
   • Successful scale-out: The cluster status is Running. The resources used in the old nodes and expanded nodes are charged.
   • Failed scale-out: The cluster status is Running. You can execute jobs and scale out the cluster again.

   After the cluster is scaled out, you can view the node information of the cluster on the Nodes page.

Adding a Task Node

You can scale out an MRS cluster by manually adding task nodes.

To add a task node to a custom cluster, perform the following steps:

1. On the cluster details page, click the Nodes tab and click Add Node Group. The Add Node Group page is displayed.
2. Select Task forNode Type. Retain the default value NM for Deploy Roles. To deploy the NodeManager role, the node type must be Task. Set other parameters as required.
   Figure 1 Adding a task node group
   

Adding a Node Group

Used to add node groups and applies to customized clusters of MRS 3.x.

1. On the cluster details page, click the Nodes tab and click Add Node Group. The Add Node Group page is displayed.
   Figure 2 Clicking Add Node Group
   
2. Set the parameters as needed.
3. Click OK.