YARN Container Resources

A YARN application can be a MapReduce v2 application or a non-MapReduce application. The Warden on each node calculates the resources that can be allocated to process YARN applications. Each application has an Application Master that negotiates YARN container resources. For MapReduce applications, YARN processes each map or reduce task in a container. The Application Master requests resources from the Resource Manager based on memory, CPU, and disk requirements for the YARN containers. For YARN containers that process MapReduce v2 tasks, there are additional considerations. See YARN Container Resource Allocation for MapReduce v2 Applications for details.

The Application Master requests YARN container resources based on the values of the following parameters:

Parameter	Default	Description
`yarn.scheduler.minimum-allocation-mb`	1024	Defines the minimum memory allocation available for a container in MB. To change the value, edit the yarn-site.xml file for the node that runs the ResourceManager. Assign the new value to this property, then restart the ResourceManager.
`yarn.scheduler.maximum-allocation-mb`	8192	Defines the maximum memory allocation available for a container in MB To change the value, edit the yarn-site.xml file for the node that runs the ResourceManager. Assign the new value to this property, then restart the ResourceManager.
`yarn.nodemanager.resource.memory-mb`	Variable. This value is calculated by Warden.	Defines the memory available to processing Yarn containers on the node in MB. Warden uses the following formula to calculate this value: `[total physical memory on node] – [memory required by the operating system, MapR-FS, and MapR services installed on the node]-[memory allocated to MapReduce v1 jobs, if TaskTracker is installed on the node]`. To determine the value, go to the ResourceManager UI and view the memory available for that node.
`yarn.nodemanager.resource.cpu-vcores`	Variable. This value is calculated by Warden.	Defines the number of CPUs available to process YARN containers on this node. Warden uses the following formula to calculate this value: `[# CPU cores on node] – [# of CPU cores assigned to Mapr-FS]-[# of CPU cores assigned to MapReduce v1 jobs, if Task Tracker is installed on the node]`. To determine the value, go to the ResourceManager UI or the YARN pane on the MCS and view the number of CPUs available for that node. To change the value, edit the yarn-site.xml file for the node, assign the new value to this property, then restart the NodeManager.
`yarn.nodemanager.resource.io-spindles`	Variable. This value is calculated by Warden.	Defines the number of disks available to process YARN containers. Warden uses the following formula to calculate this value: `[# of disk on the node] – [# of disks assigned to process MapReduce v1 jobs]`. To determine the value, go to the ResourceManager UI or the YARN pane in the MCS and view the disk information for this node.