org.apache.hadoop.yarn.client.api.impl

Class SharedCacheClientImpl

java.lang.Object

org.apache.hadoop.service.AbstractService

org.apache.hadoop.yarn.client.api.SharedCacheClient

org.apache.hadoop.yarn.client.api.impl.SharedCacheClientImpl

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.service.Service

@InterfaceAudience.Private
 @InterfaceStability.Unstable
public class SharedCacheClientImpl
extends SharedCacheClient

An implementation of the SharedCacheClient API.

Nested Class Summary

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

org.apache.hadoop.service.Service.STATE

Constructor Summary

Constructors

Constructor and Description
SharedCacheClientImpl()

Method Summary

Modifier and Type	Method and Description
protected org.apache.hadoop.yarn.api.ClientSCMProtocol	createClientProxy()
String	getFileChecksum(org.apache.hadoop.fs.Path sourceFile) A convenience method to calculate the checksum of a specified file.
void	release(org.apache.hadoop.yarn.api.records.ApplicationId applicationId, String resourceKey) The method to release a resource with the SharedCacheManager. This method is called once an application is no longer using a claimed resource in the shared cache.
protected void	serviceInit(org.apache.hadoop.conf.Configuration conf)
protected void	serviceStart()
protected void	serviceStop()
protected void	stopClientProxy()
org.apache.hadoop.yarn.api.records.URL	use(org.apache.hadoop.yarn.api.records.ApplicationId applicationId, String resourceKey) The method to claim a resource with the SharedCacheManager. The client uses a checksum to identify the resource and an ApplicationId to identify which application will be using the resource.

Methods inherited from class org.apache.hadoop.yarn.client.api.SharedCacheClient

createSharedCacheClient

Methods inherited from class org.apache.hadoop.service.AbstractService

close, getBlockers, getConfig, getFailureCause, getFailureState, getLifecycleHistory, getName, getServiceState, getStartTime, init, isInState, noteFailure, putBlocker, registerGlobalListener, registerServiceListener, removeBlocker, setConfig, start, stop, toString, unregisterGlobalListener, unregisterServiceListener, waitForServiceToStop

Methods inherited from class java.lang.Object

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

Constructor Detail

SharedCacheClientImpl

public SharedCacheClientImpl()

Method Detail

serviceInit

protected void serviceInit(org.apache.hadoop.conf.Configuration conf)
                    throws Exception

Overrides:

serviceInit in class org.apache.hadoop.service.AbstractService

Throws:

Exception

serviceStart

protected void serviceStart()
                     throws Exception

Overrides:

serviceStart in class org.apache.hadoop.service.AbstractService

Throws:

Exception

serviceStop

protected void serviceStop()
                    throws Exception

Overrides:

serviceStop in class org.apache.hadoop.service.AbstractService

Throws:

Exception

createClientProxy

protected org.apache.hadoop.yarn.api.ClientSCMProtocol createClientProxy()

stopClientProxy

protected void stopClientProxy()

use

public org.apache.hadoop.yarn.api.records.URL use(org.apache.hadoop.yarn.api.records.ApplicationId applicationId,
                                                  String resourceKey)
                                           throws org.apache.hadoop.yarn.exceptions.YarnException

Description copied from class: SharedCacheClient

The method to claim a resource with the SharedCacheManager. The client uses a checksum to identify the resource and an ApplicationId to identify which application will be using the resource.

The SharedCacheManager responds with whether or not the resource exists in the cache. If the resource exists, a URL to the resource in the shared cache is returned. If the resource does not exist, null is returned instead.

Once a URL has been returned for a resource, that URL is safe to use for the lifetime of the application that corresponds to the provided ApplicationId.

Specified by:

use in class SharedCacheClient

Parameters:

applicationId - ApplicationId of the application using the resource

resourceKey - the key (i.e. checksum) that identifies the resource

Returns:

URL to the resource, or null if it does not exist

Throws:

org.apache.hadoop.yarn.exceptions.YarnException

release

public void release(org.apache.hadoop.yarn.api.records.ApplicationId applicationId,
                    String resourceKey)
             throws org.apache.hadoop.yarn.exceptions.YarnException

Description copied from class: SharedCacheClient

The method to release a resource with the SharedCacheManager. This method is called once an application is no longer using a claimed resource in the shared cache. The client uses a checksum to identify the resource and an ApplicationId to identify which application is releasing the resource.

Note: This method is an optimization and the client is not required to call it for correctness.

Specified by:

release in class SharedCacheClient

Parameters:

applicationId - ApplicationId of the application releasing the resource

resourceKey - the key (i.e. checksum) that identifies the resource

Throws:

org.apache.hadoop.yarn.exceptions.YarnException

getFileChecksum

public String getFileChecksum(org.apache.hadoop.fs.Path sourceFile)
                       throws IOException

Description copied from class: SharedCacheClient

A convenience method to calculate the checksum of a specified file.

Specified by:

getFileChecksum in class SharedCacheClient

Parameters:

sourceFile - A path to the input file

Returns:

A hex string containing the checksum digest

Throws:

IOException