/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.mapreduce.v2.app.speculate;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptStatusUpdateEvent.TaskAttemptStatus;
import org.apache.hadoop.yarn.event.EventHandler;
/**
* Speculator component. Task Attempts' status updates are sent to this
* component. Concrete implementation runs the speculative algorithm and
* sends the TaskEventType.T_ADD_ATTEMPT.
*
* An implementation also has to arrange for the jobs to be scanned from
* time to time, to launch the speculations.
*/
public interface Speculator
extends EventHandler<SpeculatorEvent> {
enum EventType {
ATTEMPT_STATUS_UPDATE,
ATTEMPT_START,
TASK_CONTAINER_NEED_UPDATE,
JOB_CREATE
}
// This will be implemented if we go to a model where the events are
// processed within the TaskAttempts' state transitions' code.
public void handleAttempt(TaskAttemptStatus status);
}