## org.apache.hadoop.mapred
Class JobHistory.Task

    java.lang.Object
      org.apache.hadoop.mapred.JobHistory.Task

Direct Known Subclasses:
  JobHistory.TaskAttempt

Enclosing class:
  JobHistory

    public static class JobHistory.Task

extends Object

Helper class for logging or reading back events related to Task's start, finish or failure. All events logged by this class are logged in a separate file per job in job tracker history. These events map to TIPs in jobtracker.

Constructor Summary
`JobHistory.Task()`

Method Summary
`String` `get(JobHistory.Keys k)` Get 'String' value for given key.
`int` `getInt(JobHistory.Keys k)` Convert value from history to int and return.
`long` `getLong(JobHistory.Keys k)` Convert value from history to int and return.
`Map<String,JobHistory.TaskAttempt>` `getTaskAttempts()` Returns all task attempts for this task.
`Map<JobHistory.Keys,String>` `getValues()` Returns Map containing all key-values.
`void` `handle(Map<JobHistory.Keys,String> values)` Reads values back from the history, input is same Map as passed to Listener by parseHistory().
`static void` `logFailed(TaskID taskId, String taskType, long time, String error)` Log job failed event.
`static void` `logFailed(TaskID taskId, String taskType, long time, String error, TaskAttemptID failedDueToAttempt)`
`static void` `logFinished(TaskID taskId, String taskType, long finishTime, Counters counters)` Log finish time of task.
`static void` `logStarted(TaskID taskId, String taskType, long startTime, String splitLocations)` Log start time of task (TIP).
`static void` `logUpdates(TaskID taskId, long finishTime)` Update the finish time of task.
`void` `set(JobHistory.Keys k, String s)` Set value for the key.
`void` `set(Map<JobHistory.Keys,String> m)` Adds all values in the Map argument to its own values.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### JobHistory.Task

    public JobHistory.Task()

Method Detail

### logStarted

    public static void logStarted(TaskID taskId,
                                  String taskType,
                                  long startTime,
                                  String splitLocations)

  Log start time of task (TIP).

  Parameters:
    `taskId` - task id
    `taskType` - MAP or REDUCE
    `startTime` - startTime of tip.

### logFinished

    public static void logFinished(TaskID taskId,
                                   String taskType,
                                   long finishTime,
                                   Counters counters)

  Log finish time of task.

  Parameters:
    `taskId` - task id
    `taskType` - MAP or REDUCE
    `finishTime` - finish timeof task in ms

### logUpdates

    public static void logUpdates(TaskID taskId,
                                  long finishTime)

  Update the finish time of task.

  Parameters:
    `taskId` - task id
    `finishTime` - finish time of task in ms

### logFailed

    public static void logFailed(TaskID taskId,
                                 String taskType,
                                 long time,
                                 String error)

  Log job failed event.

  Parameters:
    `taskId` - task id
    `taskType` - MAP or REDUCE.
    `time` - timestamp when job failed detected.
    `error` - error message for failure.

### logFailed

    public static void logFailed(TaskID taskId,
                                 String taskType,
                                 long time,
                                 String error,
                                 TaskAttemptID failedDueToAttempt)

  Parameters:
    `failedDueToAttempt` - The attempt that caused the failure, if any

### getTaskAttempts

    public Map<String,JobHistory.TaskAttempt> getTaskAttempts()

  Returns all task attempts for this task. <task attempt id - TaskAttempt>

### get

    public String get(JobHistory.Keys k)

  Get 'String' value for given key. Most of the places use Strings as values so the default get' method returns 'String'. This method never returns null to ease on GUIs. if no value is found it returns empty string ""

  Parameters:
    `k` -
  Returns:
    if null it returns empty string - ""

### getInt

    public int getInt(JobHistory.Keys k)

  Convert value from history to int and return. if no value is found it returns 0.

  Parameters:
    `k` - key

### getLong

    public long getLong(JobHistory.Keys k)

  Convert value from history to int and return. if no value is found it returns 0.

  Parameters:
    `k` -

### set

    public void set(JobHistory.Keys k,
                    String s)

  Set value for the key.

  Parameters:
    `k` -
    `s` -

### set

    public void set(Map<JobHistory.Keys,String> m)

  Adds all values in the Map argument to its own values.

  Parameters:
    `m` -

### handle

    public void handle(Map<JobHistory.Keys,String> values)

  Reads values back from the history, input is same Map as passed to Listener by parseHistory().

  Parameters:
    `values` -

### getValues

    public Map<JobHistory.Keys,String> getValues()

  Returns Map containing all key-values.

Copyright © 2009 The Apache Software Foundation