Cloudera Docs

Configuring the resource capacity of root queue in absolute mode

In absolute resource allocation mode when you remove or add new resources to your cluster, you can update the resource capacity for the root queue accordingly. You can configure the capacity of the root queue using the YARN Queue Manager UI.

In absolute resource allocation mode when the available resource capacity changes permanently in the cluster or in a partition, reconfiguring the resource capacity of the root queue might be needed.

In case of a resource capacity increase, you can update the root queue directly.

However, if there was a decrease in the available resource capacity, you cannot update the root queue until child queues have been updated. In a case like this, you must update resource capacities starting from the lowest queue level. This is because a parent queue’s capacity cannot be decreased until the total resource capacity of all of its child queue is reduced.

  1. In Cloudera Manager navigate to Clusters > YARN Queue Manager UI.
    The Overview tab is opened, displaying a hierarchical view of the queues.
  2. Optional: If there was a decrease in the available resources, configure the resource capacity of the child queues.
    You must update resource capacities starting from the lowest queue level. This is because a parent queue’s capacity cannot be decreased until the total resource capacity of all of its child queue is reduced. You might have to change both the minimum and maximum values.
  3. Click the three vertical dots next to the root queue.
  4. Select Edit Root Queue.
    The Accessible Cluster Capacity dialog box is displayed.
  5. Configure resource capacity for the root queue.
    The Accessible Cluster Capacity dialog box provides information about the available resources:
    • Total Configured Memory and the delta to be adjusted
    • Total Configured vCores and the delta to be adjusted

    If there was an increase in the resource capacity, the Accessible Cluster Capacity dialog box looks similar to the following:

    If there was a decrease in the resource capacity, the Accessible Cluster Capacity dialog box looks similar to the following:

  6. Click Save.
    If the adjustable delta is less than zero, you cannot save the updated configuration.

After saving the resource capacity of the root queue, the Failed to update queue configuration error message is displayed with the following details: Validation failed for modify queue operation. Error message: CapacityScheduler configuration validation failed:java.io.IOException: Failed to re-init queues : Parent Queues capacity: <memory:[***CONFIGURED MEMORY OF THE ROOT QUEUE***], vCores:[***CONFIGURED vCORES OF THE ROOT QUEUE***]> is less than to its children:<memory:[***CONFIGURED MEMORY OF THE CHILD QUEUES***], vCores:[***CONFIGURED vCORES OF THE CHILD QUEUES***]> for queue:root

This error message appears when there was a decrease in the available resources and you updated the resource capacity of the root queue before updating the child queues.

To resolve this issue, update the resource capacity of the child queues first, and then update the root queue.