org.apache.hadoop.mapred
Class TaskLog

java.lang.Object
  org.apache.hadoop.mapred.TaskLog

public class TaskLog
extends Object

A simple logger to handle the task-specific user logs. This class uses the system property hadoop.log.dir.

Nested Class Summary

static class

TaskLog.LogName The filter for userlogs.

Constructor Summary

TaskLog()

Method Summary

static String	addCommand(List<String> cmd, boolean isExecutable) Add quotes to each of the command strings and return as a single string
static List<String>	captureDebugOut(List<String> cmd, File debugoutFilename) Wrap a command in a shell to capture debug script's stdout and stderr to debugout.
static List<String>	captureOutAndError(List<String> cmd, File stdoutFilename, File stderrFilename, long tailLength) Wrap a command in a shell to capture stdout and stderr to files.
static List<String>	captureOutAndError(List<String> setup, List<String> cmd, File stdoutFilename, File stderrFilename, long tailLength) Wrap a command in a shell to capture stdout and stderr to files.
static void	cleanup(int logsRetainHours) Purge old user logs.
static File	getTaskLogFile(String taskid, TaskLog.LogName filter) Deprecated.
static File	getTaskLogFile(TaskAttemptID taskid, TaskLog.LogName filter)
static long	getTaskLogLength(JobConf conf) Get the desired maximum length of task's logs.

Methods inherited from class java.lang.Object

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

Constructor Detail

TaskLog

public TaskLog()

Method Detail

getTaskLogFile

@Deprecated
public static File getTaskLogFile(String taskid,
                                             TaskLog.LogName filter)

Deprecated.

getTaskLogFile

public static File getTaskLogFile(TaskAttemptID taskid,
                                  TaskLog.LogName filter)

cleanup

public static void cleanup(int logsRetainHours)
                    throws IOException

Purge old user logs.

Throws:

IOException

getTaskLogLength

public static long getTaskLogLength(JobConf conf)

Get the desired maximum length of task's logs.

Parameters:

conf - the job to look in

Returns:

the number of bytes to cap the log files at

captureOutAndError

public static List<String> captureOutAndError(List<String> cmd,
                                              File stdoutFilename,
                                              File stderrFilename,
                                              long tailLength)
                                       throws IOException

Wrap a command in a shell to capture stdout and stderr to files. If the tailLength is 0, the entire output will be saved.

Parameters:

cmd - The command and the arguments that should be run

stdoutFilename - The filename that stdout should be saved to

stderrFilename - The filename that stderr should be saved to

tailLength - The length of the tail to be saved.

Returns:

the modified command that should be run

Throws:

IOException

captureOutAndError

public static List<String> captureOutAndError(List<String> setup,
                                              List<String> cmd,
                                              File stdoutFilename,
                                              File stderrFilename,
                                              long tailLength)
                                       throws IOException

Wrap a command in a shell to capture stdout and stderr to files. Setup commands such as setting memory limit can be passed which will be executed before exec. If the tailLength is 0, the entire output will be saved.

Parameters:

setup - The setup commands for the execed process.

cmd - The command and the arguments that should be run

stdoutFilename - The filename that stdout should be saved to

stderrFilename - The filename that stderr should be saved to

tailLength - The length of the tail to be saved.

Returns:

the modified command that should be run

Throws:

IOException

addCommand

public static String addCommand(List<String> cmd,
                                boolean isExecutable)
                         throws IOException

Add quotes to each of the command strings and return as a single string

Parameters:

cmd - The command to be quoted

isExecutable - makes shell path if the first argument is executable

Returns:

returns The quoted string.

Throws:

IOException

captureDebugOut

public static List<String> captureDebugOut(List<String> cmd,
                                           File debugoutFilename)
                                    throws IOException

Wrap a command in a shell to capture debug script's stdout and stderr to debugout.

Parameters:

cmd - The command and the arguments that should be run

debugoutFilename - The filename that stdout and stderr should be saved to.

Returns:

the modified command that should be run

Throws:

IOException