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.
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.