eu.stratosphere.nephele.jobmanager.splitassigner.DefaultInputSplitAssigner Maven / Gradle / Ivy
/***********************************************************************************************************************
* 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.jobmanager.splitassigner;
import java.util.Arrays;
import java.util.Queue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import eu.stratosphere.core.io.InputSplit;
import eu.stratosphere.nephele.executiongraph.ExecutionGroupVertex;
import eu.stratosphere.nephele.executiongraph.ExecutionVertex;
import eu.stratosphere.nephele.jobgraph.JobID;
/**
* This is the default implementation of the {@link InputSplitAssigner} interface. The default input split assigner
* simply returns all input splits of an input vertex in the order they were originally computed. The default input
* split assigner is always used when a more specific {@link InputSplitAssigned} could not be found.
*
* This class is thread-safe.
*
*/
public class DefaultInputSplitAssigner implements InputSplitAssigner {
/**
* The logging object used to report information and errors.
*/
private static final Log LOG = LogFactory.getLog(DefaultInputSplitAssigner.class);
/**
* The split map stores a list of all input splits that still must be consumed by a specific input vertex.
*/
private final ConcurrentMap> splitMap = new ConcurrentHashMap>();
@Override
public void registerGroupVertex(final ExecutionGroupVertex groupVertex) {
final InputSplit[] inputSplits = groupVertex.getInputSplits();
if (inputSplits == null) {
return;
}
if (inputSplits.length == 0) {
return;
}
final Queue queue = new ConcurrentLinkedQueue();
if (this.splitMap.putIfAbsent(groupVertex, queue) != null) {
LOG.error("Group vertex " + groupVertex.getName() + " already has a split queue");
}
queue.addAll(Arrays.asList(inputSplits));
}
@Override
public void unregisterGroupVertex(final ExecutionGroupVertex groupVertex) {
this.splitMap.remove(groupVertex);
}
@Override
public InputSplit getNextInputSplit(final ExecutionVertex vertex) {
final Queue queue = this.splitMap.get(vertex.getGroupVertex());
if (queue == null) {
final JobID jobID = vertex.getExecutionGraph().getJobID();
LOG.error("Cannot find split queue for vertex " + vertex.getGroupVertex() + " (job " + jobID + ")");
return null;
}
InputSplit nextSplit = queue.poll();
if (LOG.isDebugEnabled() && nextSplit != null) {
LOG.debug("Assigning split " + nextSplit.getSplitNumber() + " to " + vertex);
}
return nextSplit;
}
}