org.apache.hadoop.mapred

类 TaskController

java.lang.Object

org.apache.hadoop.mapred.TaskController

所有已实现的接口:

Configurable

直接已知子类:

DefaultTaskController

public abstract class TaskController
extends Object
implements Configurable

Controls initialization, finalization and clean up of tasks, and also the launching and killing of task JVMs. This class defines the API for initializing, finalizing and cleaning up of tasks, as also the launching and killing task JVMs. Subclasses of this class will implement the logic required for performing the actual actions.
NOTE: This class is internal only class and not intended for users!!

字段概要

字段

限定符和类型	字段和说明
protected LocalDirAllocator	allocator
protected static String	COMMAND_FILE
protected org.apache.hadoop.mapred.TaskTracker.LocalStorage	localStorage
static org.apache.commons.logging.Log	LOG
static FsPermission	TASK_LAUNCH_SCRIPT_PERMISSION

构造器概要

构造器

构造器和说明
TaskController()

方法概要

方法

限定符和类型	方法和说明
abstract void	createLogDir(TaskAttemptID taskID, boolean isCleanup) Creates task log dir
abstract void	deleteAsUser(String user, String subDir) Delete the user's files under all of the task tracker root directories.
abstract void	deleteLogAsUser(String user, String subDir) Delete the user's files under the userlogs directory.
Configuration	getConf() Return the configuration used by this object.
String[]	getLocalDirs()
String	getRunAsUser(JobConf conf) Returns the local unix user that a given job will run as.
abstract void	initializeJob(String user, String jobid, Path credentials, Path jobConf, TaskUmbilicalProtocol taskTracker, InetSocketAddress ttAddr) Create all of the directories necessary for the job to start and download all of the job and private distributed cache files.
abstract int	launchTask(String user, String jobId, String attemptId, List<String> setup, List<String> jvmArguments, File currentWorkDirectory, String stdout, String stderr) Create all of the directories for the task and launches the child jvm.
protected void	logOutput(String output)
void	setConf(Configuration conf) Set the configuration to be used by this object.
abstract void	setup(LocalDirAllocator allocator, org.apache.hadoop.mapred.TaskTracker.LocalStorage localStorage) Does initialization and setup.
abstract void	signalTask(String user, int taskPid, ProcessTree.Signal signal) Send a signal to a task pid as the user.
abstract void	truncateLogsAsUser(String user, List<Task> allAttempts) Run the passed command as the user
protected static String	writeCommand(String cmdLine, FileSystem fs, Path commandFile)

从类继承的方法 java.lang.Object

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

字段详细资料

LOG

public static final org.apache.commons.logging.Log LOG

COMMAND_FILE

protected static final String COMMAND_FILE

另请参阅:

常量字段值

allocator

protected LocalDirAllocator allocator

localStorage

protected org.apache.hadoop.mapred.TaskTracker.LocalStorage localStorage

TASK_LAUNCH_SCRIPT_PERMISSION

public static final FsPermission TASK_LAUNCH_SCRIPT_PERMISSION

构造器详细资料

TaskController

public TaskController()

方法详细资料

getConf

public Configuration getConf()

从接口复制的说明: Configurable

Return the configuration used by this object.

指定者:

getConf 在接口中 Configurable

getLocalDirs

public String[] getLocalDirs()

setConf

public void setConf(Configuration conf)

从接口复制的说明: Configurable

Set the configuration to be used by this object.

指定者:

setConf 在接口中 Configurable

setup

public abstract void setup(LocalDirAllocator allocator,
         org.apache.hadoop.mapred.TaskTracker.LocalStorage localStorage)
                    throws IOException

Does initialization and setup.

参数:

allocator - the local dir allocator to use

localStorage - local storage to obtain dirs from

抛出:

IOException

initializeJob

public abstract void initializeJob(String user,
                 String jobid,
                 Path credentials,
                 Path jobConf,
                 TaskUmbilicalProtocol taskTracker,
                 InetSocketAddress ttAddr)
                            throws IOException,
                                   InterruptedException

Create all of the directories necessary for the job to start and download all of the job and private distributed cache files. Creates both the user directories and the job log directory.

参数:

user - the user name

jobid - the job

credentials - a filename containing the job secrets

jobConf - the path to the localized configuration file

taskTracker - the connection the task tracker

ttAddr - the tasktracker's RPC address

抛出:

IOException

InterruptedException

launchTask

public abstract int launchTask(String user,
             String jobId,
             String attemptId,
             List<String> setup,
             List<String> jvmArguments,
             File currentWorkDirectory,
             String stdout,
             String stderr)
                        throws IOException

Create all of the directories for the task and launches the child jvm.

参数:

user - the user name

jobId - the jobId in question

attemptId - the attempt id (cleanup attempts have .cleanup suffix)

setup - list of shell commands to execute before the jvm

jvmArguments - list of jvm arguments

currentWorkDirectory - the full path of the cwd for the task

stdout - the file to redirect stdout to

stderr - the file to redirect stderr to

返回:

the exit code for the task

抛出:

IOException

signalTask

public abstract void signalTask(String user,
              int taskPid,
              ProcessTree.Signal signal)
                         throws IOException

Send a signal to a task pid as the user.

参数:

user - the user name

taskPid - the pid of the task

signal - the id of the signal to send

抛出:

IOException

deleteAsUser

public abstract void deleteAsUser(String user,
                String subDir)
                           throws IOException

Delete the user's files under all of the task tracker root directories.

参数:

user - the user name

subDir - the path relative to the user's subdirectory under the task tracker root directories.

抛出:

IOException

createLogDir

public abstract void createLogDir(TaskAttemptID taskID,
                boolean isCleanup)
                           throws IOException

Creates task log dir

参数:

taskID - ID of the task

isCleanup - If the task is cleanup task or not

抛出:

IOException

deleteLogAsUser

public abstract void deleteLogAsUser(String user,
                   String subDir)
                              throws IOException

Delete the user's files under the userlogs directory.

参数:

user - the user to work as

subDir - the path under the userlogs directory.

抛出:

IOException

truncateLogsAsUser

public abstract void truncateLogsAsUser(String user,
                      List<Task> allAttempts)
                                 throws IOException

Run the passed command as the user

参数:

user -

allAttempts - the list of attempts that the JVM ran

抛出:

IOException

getRunAsUser

public String getRunAsUser(JobConf conf)

Returns the local unix user that a given job will run as.

writeCommand

protected static String writeCommand(String cmdLine,
                  FileSystem fs,
                  Path commandFile)
                              throws IOException

抛出:

IOException

logOutput

protected void logOutput(String output)