org.apache.flink.runtime.jobmanager.scheduler.CoLocationGroup Maven / Gradle / Ivy
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* 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.flink.runtime.jobmanager.scheduler;
import java.util.ArrayList;
import java.util.List;
import org.apache.flink.runtime.jobgraph.JobVertex;
import org.apache.flink.util.AbstractID;
import org.apache.flink.util.Preconditions;
/**
* A Co-location group is a group of JobVertices, where the i-th subtask of one vertex
* has to be executed on the same TaskManager as the i-th subtask of all
* other JobVertices in the same group.
*
* The co-location group is used for example to make sure that the i-th subtasks for iteration
* head and iteration tail are scheduled to the same TaskManager.
*/
public class CoLocationGroup implements java.io.Serializable {
private static final long serialVersionUID = -2605819490401895297L;
/** The ID that describes the slot co-location-constraint as a group */
private final AbstractID id = new AbstractID();
/** The vertices participating in the co-location group */
private final List vertices = new ArrayList();
/** The constraints, which hold the shared slots for the co-located operators */
private transient ArrayList constraints;
// --------------------------------------------------------------------------------------------
public CoLocationGroup() {}
public CoLocationGroup(JobVertex... vertices) {
for (JobVertex v : vertices) {
this.vertices.add(v);
}
}
// --------------------------------------------------------------------------------------------
public void addVertex(JobVertex vertex) {
Preconditions.checkNotNull(vertex);
this.vertices.add(vertex);
}
public void mergeInto(CoLocationGroup other) {
Preconditions.checkNotNull(other);
for (JobVertex v : this.vertices) {
v.updateCoLocationGroup(other);
}
// move vertex membership
other.vertices.addAll(this.vertices);
this.vertices.clear();
}
// --------------------------------------------------------------------------------------------
public CoLocationConstraint getLocationConstraint(int subtask) {
ensureConstraints(subtask + 1);
return constraints.get(subtask);
}
private void ensureConstraints(int num) {
if (constraints == null) {
constraints = new ArrayList(num);
} else {
constraints.ensureCapacity(num);
}
if (num > constraints.size()) {
constraints.ensureCapacity(num);
for (int i = constraints.size(); i < num; i++) {
constraints.add(new CoLocationConstraint(this));
}
}
}
/**
* Gets the ID that identifies this co-location group.
*
* @return The ID that identifies this co-location group.
*/
public AbstractID getId() {
return id;
}
/**
* Resets this co-location group, meaning that future calls to {@link #getLocationConstraint(int)}
* will give out new CoLocationConstraints.
*
* This method can only be called when no tasks from any of the CoLocationConstraints are
* executed any more.
*/
public void resetConstraints() {
for (CoLocationConstraint c : this.constraints) {
if (c.isAssignedAndAlive()) {
throw new IllegalStateException(
"Cannot reset co-location group: some constraints still have live tasks");
}
}
this.constraints.clear();
}
}