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    E-MapReduce:node compensation

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    E-MapReduce:node compensation

    Last Updated:Sep 16, 2026

    When automatic compensation is enabled for a node group, E-MapReduce (EMR) automatically handles faulty ECS instances that can no longer run engine services. For pay-as-you-go task nodes, EMR creates a new ECS instance to replace the faulty one. For subscription task nodes, EMR redeploys the faulty instance.

    Prerequisites

    You have created a DataLake, DataFlow, or Custom cluster with the YARN service deployed. For more information, see Create a cluster.

    Limitations

    Only task node groups support this feature.

    Usage notes

    • Automatic compensation may fail in the following situations:

      • The ECS instance to be replaced has a system issue.

      • Release protection is enabled for the ECS instance to be replaced.

      • The number of nodes in the node group is less than or equal to the configured minimum.

    • Bootstrap action scripts run automatically on the new ECS instance during scale-out. However, you must manually redeploy any components or services that were manually deployed on the original instance.

    Enable or disable automatic compensation

    1. Go to the node management page.

      1. Log on to the EMR console.

      2. In the top navigation bar, select a region and a resource group as needed.

      3. In the Actions column of the target cluster, click Nodes.

    2. On the Nodes page, click the name of a node group.

    3. In the Node Group Attributes panel, turn the Automatic Compensation switch on or off.

      Note

      Starting from 18:00 (UTC+8) on July 10, 2023, the Automatic Compensation switch is enabled by default when you create a pay-as-you-go task node group.

    4. In the dialog box that appears, click OK.

    5. Click Save.

    View automatic compensation status

    The Nodes page displays the automatic compensation status.

    If automatic compensation was triggered for a node group in the last week, the Automatic Supplementation column shows the number of occurrences. Hover over the count and click View event details in the tooltip.