com.linkedin.pinot.routing.builder.RandomRoutingTableBuilder.java Source code

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Here is the source code for com.linkedin.pinot.routing.builder.RandomRoutingTableBuilder.java

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/**
 * 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;

    }
}