org.apache.hadoop.yarn.client

Interface AMRMClient

All Superinterfaces:

org.apache.hadoop.yarn.service.Service

All Known Implementing Classes:

AMRMClientImpl

@InterfaceAudience.Public
@InterfaceStability.Unstable
public interface AMRMClient
extends org.apache.hadoop.yarn.service.Service

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	AMRMClient.ContainerRequest Object to represent container request for resources.

Nested classes/interfaces inherited from interface org.apache.hadoop.yarn.service.Service

org.apache.hadoop.yarn.service.Service.STATE

Field Summary

Fields

Modifier and Type	Field and Description
static String	ANY Value used to define no locality

Method Summary

Methods

Modifier and Type	Method and Description
void	addContainerRequest(AMRMClient.ContainerRequest req) Request containers for resources before calling allocate
org.apache.hadoop.yarn.api.protocolrecords.AllocateResponse	allocate(float progressIndicator) Request additional containers and receive new container allocations.
org.apache.hadoop.yarn.api.records.Resource	getClusterAvailableResources() Get the currently available resources in the cluster.
int	getClusterNodeCount() Get the current number of nodes in the cluster.
org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterResponse	registerApplicationMaster(String appHostName, int appHostPort, String appTrackingUrl) Register the application master.
void	releaseAssignedContainer(org.apache.hadoop.yarn.api.records.ContainerId containerId) Release containers assigned by the Resource Manager.
void	removeContainerRequest(AMRMClient.ContainerRequest req) Remove previous container request.
void	unregisterApplicationMaster(org.apache.hadoop.yarn.api.records.FinalApplicationStatus appStatus, String appMessage, String appTrackingUrl) Unregister the application master.

Methods inherited from interface org.apache.hadoop.yarn.service.Service

getConfig, getName, getServiceState, getStartTime, init, register, start, stop, unregister

Field Detail

ANY

static final String ANY

Value used to define no locality

See Also:

Constant Field Values

Method Detail

registerApplicationMaster

org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterResponse registerApplicationMaster(String appHostName,
                                                                                                     int appHostPort,
                                                                                                     String appTrackingUrl)
                                                                                                       throws org.apache.hadoop.yarn.exceptions.YarnRemoteException

Register the application master. This must be called before any other interaction

Parameters:

appHostName - Name of the host on which master is running

appHostPort - Port master is listening on

appTrackingUrl - URL at which the master info can be seen

Returns:

RegisterApplicationMasterResponse

Throws:

org.apache.hadoop.yarn.exceptions.YarnRemoteException

allocate

org.apache.hadoop.yarn.api.protocolrecords.AllocateResponse allocate(float progressIndicator)
                                                                     throws org.apache.hadoop.yarn.exceptions.YarnRemoteException

Request additional containers and receive new container allocations. Requests made via addContainerRequest are sent to the ResourceManager. New containers assigned to the master are retrieved. Status of completed containers and node health updates are also retrieved. This also doubles up as a heartbeat to the ResourceManager and must be made periodically. The call may not always return any new allocations of containers. App should not make concurrent allocate requests. May cause request loss.

Parameters:

progressIndicator - Indicates progress made by the master

Returns:

the response of the allocate request

Throws:

org.apache.hadoop.yarn.exceptions.YarnRemoteException

unregisterApplicationMaster

void unregisterApplicationMaster(org.apache.hadoop.yarn.api.records.FinalApplicationStatus appStatus,
                               String appMessage,
                               String appTrackingUrl)
                                 throws org.apache.hadoop.yarn.exceptions.YarnRemoteException

Unregister the application master. This must be called in the end.

Parameters:

appStatus - Success/Failure status of the master

appMessage - Diagnostics message on failure

appTrackingUrl - New URL to get master info

Throws:

org.apache.hadoop.yarn.exceptions.YarnRemoteException

addContainerRequest

void addContainerRequest(AMRMClient.ContainerRequest req)

Request containers for resources before calling allocate

Parameters:

req - Resource request

removeContainerRequest

void removeContainerRequest(AMRMClient.ContainerRequest req)

Remove previous container request. The previous container request may have already been sent to the ResourceManager. So even after the remove request the app must be prepared to receive an allocation for the previous request even after the remove request

Parameters:

req - Resource request

releaseAssignedContainer

void releaseAssignedContainer(org.apache.hadoop.yarn.api.records.ContainerId containerId)

Release containers assigned by the Resource Manager. If the app cannot use the container or wants to give up the container then it can release them. The app needs to make new requests for the released resource capability if it still needs it. eg. it released non-local resources

Parameters:

containerId -

getClusterAvailableResources

org.apache.hadoop.yarn.api.records.Resource getClusterAvailableResources()

Get the currently available resources in the cluster. A valid value is available after a call to allocate has been made

Returns:

Currently available resources

getClusterNodeCount

int getClusterNodeCount()

Get the current number of nodes in the cluster. A valid values is available after a call to allocate has been made

Returns:

Current number of nodes in the cluster