Auto-converted Fair Scheduler properties

The fs2cs conversion utility automatically converts certain Fair Scheduler properties into Capacity Scheduler properties. Reviewing the list of auto-converted properties enables you to verify the conversion and plan the manual fine-tuning that requires to be done after the upgrade is completed.

Table 1. Queue resource-quota related features
Property	Description
Pre-created hierarchical queues.	The same queue hierarchy is achieved after conversion.
`<weight>`	Weight: The steady fair share of a queue. The `queue.capacity` property will be set with the same ratio.
`<maxAMShare>`	Maximum AM share: Limits the fraction of the queue’s fair share that can be used to run application masters
`<maxRunningApps>`	Maximum running apps: Limits the number of apps from the queue to run at once
`<maxContainerAllocation>`	Maximum container allocation: Maximum amount of resources a queue can allocate for a single container.
`<schedulingPolicy>`	Scheduling policy of a queue (for example, how submitted applications are ordered over time). It is converted with some limitations. For more information, see Fair Scheduler features and the conversion details.
`<aclSubmitApps> <aclAdministerApps>`	ACL settings: List of users and/or groups that can submit apps to the queue or can administer a queue.
`maximum-am-resource-percent`	Specifies the maximum percentage of resources in the cluster which can be used to run application masters for the queue.
`acl_submit_applications`	Specifies the ACL which controls who can submit applications to the given queue.
`acl_administer_queue`	Specifies the ACL which controls who can administer applications in the given queue.
`ordering-policy`	Specifies the queue ordering policies to FIFO or fair on the given queue.

Table 2. Global scheduling settings
Property	Description
`yarn.scheduler.fair.allow-undeclared-pools`	Allow undeclared pools. Sets whether new queues can be created at application submission time.
`yarn.scheduler.fair.sizebasedweight`	Size based weight. Whether to assign shares to individual apps based on their size, rather than providing an equal share to all apps regardless of size.
`<queueMaxAppsDefault>`	Queue max apps default: Sets the default running app limit for all queues.
`<queueMaxAMShareDefault>`	Default max AM share: Sets the default AM resource limit for queue.
`yarn.scheduler.fair.locality.threshold.node`	Locality threshold node: For applications that request containers on particular nodes, the number of scheduling opportunities since the last container assignment to wait before accepting a placement on another node.
`yarn.scheduler.fair.locality.threshold.rack`	Locality threshold rack: For applications that request containers on particular racks, the number of scheduling opportunities since the last container assignment to wait before accepting a placement on another rack.
`yarn.scheduler.fair.max.assign`	Maximum assignments: If assignmultiple is true and dynamic.max.assign is false, the maximum amount of containers that can be assigned in one heartbeat.
`yarn.scheduler.fair.assignmultiple`	Assign multiple: Whether to allow multiple container assignments in one heartbeat.
`yarn.resourcemanager.scheduler.monitor.enable`	Allows higher-priority applications to preempt lower-priority applications.
`yarn.scheduler.capacity.maximum-am-resource-percent`	Specifies the maximum percentage of resources in the cluster which can be used to run application masters.

Table 3. Global scheduling settings
Property	Description
`yarn.scheduler.fair.allow-undeclared-pools`	Allow undeclared pools. Sets whether new queues can be created at application submission time.
`yarn.scheduler.fair.sizebasedweight`	Size based weight. Whether to assign shares to individual apps based on their size, rather than providing an equal share to all apps regardless of size.
`<queueMaxAppsDefault>`	Queue max apps default: Sets the default running app limit for all queues.
`<queueMaxAMShareDefault>`	Default max AM share: Sets the default AM resource limit for queue.
`yarn.scheduler.fair.locality.threshold.node`	Locality threshold node: For applications that request containers on particular nodes, the number of scheduling opportunities since the last container assignment to wait before accepting a placement on another node.
`yarn.scheduler.fair.locality.threshold.rack`	Locality threshold rack: For applications that request containers on particular racks, the number of scheduling opportunities since the last container assignment to wait before accepting a placement on another rack.
`yarn.scheduler.fair.max.assign`	Maximum assignments: If assignmultiple is true and dynamic.max.assign is false, the maximum amount of containers that can be assigned in one heartbeat.
`yarn.scheduler.fair.assignmultiple`	Assign multiple: Whether to allow multiple container assignments in one heartbeat.
`yarn.resourcemanager.scheduler.monitor.enable`	Allows higher-priority applications to preempt lower-priority applications.
`yarn.scheduler.capacity.maximum-am-resource-percent`	Specifies the maximum percentage of resources in the cluster which can be used to run application masters.
`<userMaxAppsDefault>`	Default maximum running applications.
`<user name="..."> <maxRunningApps>...</maxRunningApps></user>`	Maximum running applications per user.
`yarn.scheduler.fair.user-as-default-queue`	Whether to use the username associated with the allocation as the default queue name. Weight mode: This behavior is simulated with a placement rule (in fact, even in Fair Scheduler, this is translated into a placement rule internally): `{ "type":"user", "matches":"*", “parentQueue”: “root”, "policy":"user", “create”: true, "fallbackResult":"skip" }` For information about percentage mode, see Fair Scheduler features ad conversion details.

Table 4. Preemption
Property	Description
`yarn.scheduler.fair.preemption`	Fair Scheduler preemption turned on. After the conversion capacity Scheduler preemption is turned on by default using the default values.
`<allowPreemptionFrom>`	Per-queue preemption disabled. After the conversion the same queue preemption disabled by default.
`yarn.scheduler.fair.waitTimeBeforeKill`	Wait time before killing a container
`disable_preemption`	Disables preemption of application containers submitted to a given queue.

Table 5. Placement rules
Fair Scheduler placement rules	Description	Conversion details
`create="false"` or `"true"`	Disable or enable creating a queue dynamically in YARN. This option cannot be specified on the following placement rule policies: `reject` `setDefaultQueue` `defaultQueue`	Weight mode: This flag is fully supported, except for nested rules, where you can define a single “create” flag only. Therefore, “true/false” and “false/true” cannot be set. Relative mode: Partially supported. A managed parent queue must be chosen as a parent. The flag has no effect on regular parent queues.
`<rule name="specified"/>`	If a user has submitted the application by specifying a queue name (other than the “default” queue), then this rule will be successful. Hence the remaining set of rules won't be executed.	Supported in both weight and percentage mode.
`<rule name="primaryGroup"/>`	If the submitted user’s(userA) primary group name (groupA) exists, submit to groupA.	The matching policy is called `primaryGroup`.
`<rule name="secondaryGroupExistingQueue"/>`	If the submitted user’s(userA) secondary group name (groupB) exists, submit to groupB.	The matching policy is called `secondaryGroup`.
`<rule name="nestedUserQueue">`	Depending on the nested rule, this places the job to the following queues: `root.[primaryGroup].[userName]` `root.[secondaryGroup].[userName]` `root.[queuePath].[userName]`	Supported by Capacity Scheduler. The three possible policies are (depending on the outer rule): `primaryGroupUser` `secondaryGroupUser` `user` with a `parentQueue` set explicitly.
`<rule name="default" queue=”qName”/>`	Places the application into the default queue called “root.default” or to a user-specific one denoted by the “queue” attribute.	The default rule has a matching policy called `defaultQueue`. If “root.default” is not the intended default queue, then two approaches are possible: Use the `setDefaultQueue` policy to change “root.default”, then apply `defaultQueue`. Use the custom policy with the policy string being set to the target queue.