io.druid.server.router.PriorityTieredBrokerSelectorStrategy.java Source code

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Here is the source code for io.druid.server.router.PriorityTieredBrokerSelectorStrategy.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * 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 io.druid.server.router;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Optional;
import com.google.common.collect.Iterables;
import io.druid.query.Query;

/**
 */
public class PriorityTieredBrokerSelectorStrategy implements TieredBrokerSelectorStrategy {
    private final int minPriority;
    private final int maxPriority;

    @JsonCreator
    public PriorityTieredBrokerSelectorStrategy(@JsonProperty("minPriority") Integer minPriority,
            @JsonProperty("maxPriority") Integer maxPriority) {
        this.minPriority = minPriority == null ? 0 : minPriority;
        this.maxPriority = maxPriority == null ? 1 : maxPriority;
    }

    @Override
    public Optional<String> getBrokerServiceName(TieredBrokerConfig tierConfig, Query query) {
        final int priority = query.getContextPriority(0);

        if (priority < minPriority) {
            return Optional.of(Iterables.getLast(tierConfig.getTierToBrokerMap().values(),
                    tierConfig.getDefaultBrokerServiceName()));
        } else if (priority >= maxPriority) {
            return Optional.of(Iterables.getFirst(tierConfig.getTierToBrokerMap().values(),
                    tierConfig.getDefaultBrokerServiceName()));
        }

        return Optional.absent();
    }
}