Package org.apache.hadoop.yarn.util

Class TaskLogUtil

java.lang.Object

org.apache.hadoop.yarn.util.TaskLogUtil

public class TaskLogUtil
extends java.lang.Object

Helper class to facilitate task logs to be directly written to DFS. DFS logging is enabled by setting the property YarnConfiguration.ENABLE_DFS_LOGGING to true in yarn-site.xml. If enabled, then the configured handler class is instantiated to provide the DFS specific behavior.

Constructor Summary

Constructors

Constructor	Description
TaskLogUtil()

Method Summary

Modifier and Type	Method	Description
static java.lang.String	getAppender()	Returns the Log4j appender to use depending on whether DFS logging is enabled or not.
static org.apache.hadoop.yarn.conf.YarnConfiguration	getConf()	Returns the cached default YarnConfiguration object used to initialize settings.
static DFSLoggingHandler	getDFSLoggingHandler()
static java.lang.String	getPropertyValue(java.lang.String property)	Returns the property value from cached default YarnConfiguration object.
static java.lang.String	getPropertyValue(java.lang.String property, java.lang.String defaultValue)	Returns the property value from cached default YarnConfiguration object.
static java.lang.String	getRollingAppender()	Returns the Log4j rolling appender to use depending on whether DFS logging is enabled or not.
static boolean	isDfsLoggingEnabled()	Determines if logs should be saved directly in DFS or written to local file system.
static boolean	isDfsLoggingEnabled(java.util.Map<java.lang.String,java.lang.String> env)	Determines if logs should be saved directly in DFS or written to local file system using the given environment.

Methods inherited from class java.lang.Object

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

Constructor Detail

TaskLogUtil

public TaskLogUtil()

Method Detail

getDFSLoggingHandler

public static DFSLoggingHandler getDFSLoggingHandler()

isDfsLoggingEnabled

public static boolean isDfsLoggingEnabled()

Determines if logs should be saved directly in DFS or written to local file system. It uses the default YarnConfiguration to determine it. To override for specific application, use the overloaded method.

Returns:

true if DFS logging is enabled globally; false otherwise

isDfsLoggingEnabled

public static boolean isDfsLoggingEnabled(java.util.Map<java.lang.String,java.lang.String> env)

Determines if logs should be saved directly in DFS or written to local file system using the given environment. In addition to the global setting defined in YarnConfiguration, it uses the given env to determine if DFS logging is supported by the application.

Parameters:

env - environment settings for the application

Returns:

true if DFS logging is enabled globally and also in the given environment; false otherwise

getConf

public static org.apache.hadoop.yarn.conf.YarnConfiguration getConf()

Returns the cached default YarnConfiguration object used to initialize settings.

getAppender

public static java.lang.String getAppender()

Returns the Log4j appender to use depending on whether DFS logging is enabled or not.

getRollingAppender

public static java.lang.String getRollingAppender()

Returns the Log4j rolling appender to use depending on whether DFS logging is enabled or not.

getPropertyValue

public static java.lang.String getPropertyValue(java.lang.String property,
                                                java.lang.String defaultValue)

Returns the property value from cached default YarnConfiguration object.

Returns:

value if property is found; otherwise defaultValue is returned

getPropertyValue

public static java.lang.String getPropertyValue(java.lang.String property)

Returns the property value from cached default YarnConfiguration object.

Returns:

value if property is found; null otherwise