/**
* Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
*
* 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 com.linkedin.pinot.routing.builder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import org.apache.commons.configuration.Configuration;
import org.apache.helix.model.ExternalView;
import org.apache.helix.model.InstanceConfig;
import com.linkedin.pinot.routing.ServerToSegmentSetMap;
/**
* Create a given number of routing tables based on random selections from ExternalView.
*/
public class RandomRoutingTableBuilder implements RoutingTableBuilder {
private int _numberOfRoutingTables;
public RandomRoutingTableBuilder() {
this._numberOfRoutingTables = 10;
}
public RandomRoutingTableBuilder(int numberOfRoutingTables) {
this._numberOfRoutingTables = numberOfRoutingTables;
}
@Override
public void init(Configuration configuration) {
_numberOfRoutingTables = configuration.getInt("numOfRoutingTables", 10);
}
@Override
public synchronized List<ServerToSegmentSetMap> computeRoutingTableFromExternalView(String tableName,
ExternalView externalView, List<InstanceConfig> instanceConfigList) {
RoutingTableInstancePruner pruner = new RoutingTableInstancePruner(instanceConfigList);
List<Map<String, Set<String>>> routingTables = new ArrayList<Map<String, Set<String>>>();
for (int i = 0; i < _numberOfRoutingTables; ++i) {
routingTables.add(new HashMap<String, Set<String>>());
}
String[] segmentSet = externalView.getPartitionSet().toArray(new String[0]);
for (String segment : segmentSet) {
Map<String, String> instanceToStateMap = externalView.getStateMap(segment);
for (String instance : instanceToStateMap.keySet().toArray(new String[0])) {
if (!instanceToStateMap.get(instance).equals("ONLINE") || pruner.isInactive(instance)) {
instanceToStateMap.remove(instance);
}
}
if (instanceToStateMap.size() > 0) {
String[] instances = instanceToStateMap.keySet().toArray(new String[0]);
Random randomSeed = new Random(System.currentTimeMillis());
for (int i = 0; i < _numberOfRoutingTables; ++i) {
String instance = instances[randomSeed.nextInt(instances.length)];
if (routingTables.get(i).containsKey(instance)) {
routingTables.get(i).get(instance).add(segment);
} else {
Set<String> instanceSegmentSet = new HashSet<String>();
instanceSegmentSet.add(segment);
routingTables.get(i).put(instance, instanceSegmentSet);
}
}
}
}
List<ServerToSegmentSetMap> resultRoutingTableList = new ArrayList<ServerToSegmentSetMap>();
for (int i = 0; i < _numberOfRoutingTables; ++i) {
resultRoutingTableList.add(new ServerToSegmentSetMap(routingTables.get(i)));
}
return resultRoutingTableList;
}
}