Package org.apache.hadoop.yarn.api.records

Class PreemptionContract

java.lang.Object

org.apache.hadoop.yarn.api.records.PreemptionContract

@Public
@Evolving
public abstract class PreemptionContract
extends Object

Description of resources requested back by the ResourceManager. The ApplicationMaster (AM) can satisfy this request according to its own priorities to prevent containers from being forcibly killed by the platform.

See Also:

• PreemptionMessage

Constructor Summary

Constructors

Constructor	Description
PreemptionContract()

Method Summary

Modifier and Type	Method	Description
abstract Set<PreemptionContainer>	getContainers()	Assign the set of PreemptionContainer specifying which containers owned by the ApplicationMaster that may be reclaimed by the ResourceManager.
abstract List<PreemptionResourceRequest>	getResourceRequest()	If the AM releases resources matching these requests, then the PreemptionContainers enumerated in getContainers() should not be evicted from the cluster.
static PreemptionContract	newInstance(List<PreemptionResourceRequest> req, Set<PreemptionContainer> containers)
abstract void	setContainers(Set<PreemptionContainer> containers)
abstract void	setResourceRequest(List<PreemptionResourceRequest> req)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PreemptionContract

public PreemptionContract()

Method Details

newInstance

@Private
@Unstable
public static PreemptionContract newInstance(List<PreemptionResourceRequest> req,
 Set<PreemptionContainer> containers)

getResourceRequest

@Public
@Evolving
public abstract List<PreemptionResourceRequest> getResourceRequest()

If the AM releases resources matching these requests, then the PreemptionContainers enumerated in getContainers() should not be evicted from the cluster. Due to delays in propagating cluster state and sending these messages, there are conditions where satisfied contracts may not prevent the platform from killing containers.

Returns:

List of PreemptionResourceRequest to update the ApplicationMaster about resources requested back by the ResourceManager.

See Also:

• AllocateRequest.setAskList(List)

setResourceRequest

@Private
@Unstable
public abstract void setResourceRequest(List<PreemptionResourceRequest> req)

getContainers

@Public
@Evolving
public abstract Set<PreemptionContainer> getContainers()

Assign the set of PreemptionContainer specifying which containers owned by the ApplicationMaster that may be reclaimed by the ResourceManager. If the AM prefers a different set of containers, then it may checkpoint or kill containers matching the description in getResourceRequest().

Returns:

Set of containers at risk if the contract is not met.

setContainers

@Private
@Unstable
public abstract void setContainers(Set<PreemptionContainer> containers)