org.apache.reef.task

Interface Task

All Known Implementing Classes:

EchoTask, FailTask, FailTaskCall, FailTaskClose, FailTaskMsg, FailTaskStart, FailTaskStop, FailTaskSuspend, HelloTask, LineCountingTask, MasterTask, MasterTask, MasterTask, NoopTask, NoopTask, OutputServiceTask, ShellTask, SlaveTask, SlaveTask, SlaveTask, SleepTask, StatePassingTask, SuspendTestTask, TaskMessagingTask, VortexWorker, WatcherTestTask

public interface Task

The interface for Tasks.

This interface is to be implemented for Tasks.

The main entry point for a Task is the call() method inherited from Callable. The REEF Evaluator will call this method in order to run the Task. The byte[] returned by it will be pushed to the Job Driver.

Method Summary

Modifier and Type	Method and Description
byte[]	call(byte[] memento) Called by the resourcemanager harness to execute the task.

Method Detail

call

byte[] call(byte[] memento)
     throws Exception

Called by the resourcemanager harness to execute the task.

Parameters:

memento - the memento objected passed down by the driver.

Returns:

the user defined return value

Throws:

Exception - whenever the Task encounters an unsolved issue. This Exception will be thrown at the Driver's event handler.