You can scale out an E-MapReduce (EMR) cluster that has insufficient computing or storage resources. This topic describes how to scale out an EMR cluster and how to change the password of a new node.

Prerequisites

An EMR cluster is created. For more information, see Create a cluster.

Limits

You can add only core nodes and task nodes. By default, the configurations of an added node are the same as those of an existing node.

Procedure

  1. Go to the Nodes tab.
    1. Log on to the EMR console.
    2. In the top navigation bar, select the region where your cluster resides and select a resource group based on your business requirements.
    3. On the EMR on ECS page, find the cluster that you want to scale out and click Nodes in the Actions column.
  2. On the Nodes tab, find the node group and click Scale Out in the Actions column.
  3. In the Scale Out dialog box, configure the parameters based on your business requirements.
    ParameterDescription
    Node Group NameThe name of the node group.
    Node TypeThe type of the node group.
    Current Instance TypeThe information about instances in the node group.
    Billing MethodThe billing method of the cluster. The billing method of a new node is the same as that of the cluster and cannot be changed. If the billing method is subscription, you can set the Subscription Duration parameter for the new node.
    Current QuantityThe number of instances in the node group.
    Added InstancesThe number of instances that you want to add to the node group. Click the upward or downward arrow or enter a number in the Added Instances field.
    Terms of ServiceRead and agree to the terms of service.
  4. Click OK.
Note If you scale out a core node group, and the cluster uses HDFS to store data, you must use an HDFS balancer to rebalance HDFS after you scale out the node group. For more information, see HDFS balancer.

Change the password of a new node

After you scale out the cluster, you can log on to the new node in SSH mode to change the password of the root user.

  1. Log on to the master node of the cluster. For more information, see Log on to a cluster.
  2. Run the following command to switch to the hadoop user:
    su hadoop
  3. Run the following command to log on to the new node:
    ssh <ip.of.worker>

    You can obtain the private IP address of the new node on the Nodes tab.

  4. Run the following command to change the password of the root user:
    sudo passwd root