When a large amount of compute resources remains idle in your E-MapReduce (EMR) cluster, you can reduce the number of task nodes in the cluster. This topic describes how to scale in a cluster.
A cluster is created on the EMR on ECS page. For more information, see Create a cluster.
- You can reduce only the number of task nodes to scale in an EMR cluster. The cluster that you want to scale in must meet the following requirements:
Note If you want to reduce the number of core nodes or subscription task nodes to scale in a cluster, follow the instructions described in Scale in a node group.
- The EMR version of the cluster is V5.X later than V5.6.0 or V3.X later than V3.2.0.
- The cluster is in the Running state.
- The billing method of the task node group is Pay-As-You-Go or Preemptible Instance.
- For Hadoop clusters, you cannot scale out a node group that is created on the Auto Scaling tab. For more information, see Configure auto scaling (only for Hadoop clusters).
- Go to the Nodes tab.
- Log on to the EMR console. In the left-side navigation pane, click EMR on ECS.
- In the top navigation bar, select the region where your cluster resides and select a resource group based on your business requirements.
- On the EMR on ECS page, find the cluster that you want to scale out and click Nodes in the Actions column.
- On the Nodes tab, click Scale In in the Actions column of the node group that you want to scale in.
- In the Scale In dialog box, click the downward arrow for Reserved Nodes or enter a number in this field to reduce the number of task nodes.
- After you complete the configuration, click OK.