/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.nephele.protocols;
import java.io.IOException;
import eu.stratosphere.core.protocols.VersionedProtocol;
import eu.stratosphere.nephele.jobgraph.JobID;
import eu.stratosphere.nephele.services.accumulators.AccumulatorEvent;
/**
* The accumulator protocol is implemented by the job manager. TaskManagers can
* use it to send the collected accumulators and JobClients can use it to get
* the final accumulator results after the job ended.
*/
public interface AccumulatorProtocol extends VersionedProtocol {
/**
* Report accumulators that were collected in a task. Called by Task
* Manager, after the user code was executed but before the task status
* update is reported.
*/
void reportAccumulatorResult(AccumulatorEvent accumulatorEvent)
throws IOException;
/**
* Get the final accumulator results. Called by JobClient after the job
* ended.
*/
AccumulatorEvent getAccumulatorResults(JobID jobID) throws IOException;
}