src/server/src/main/java/org/apache/accumulo/server/master/RoundRobinPartitioner.java

/*
 * 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.accumulo.server.master;

import org.apache.accumulo.server.logger.LogFileKey;
import org.apache.accumulo.server.logger.LogFileValue;
import org.apache.hadoop.mapreduce.Partitioner;

public class RoundRobinPartitioner extends Partitioner<LogFileKey,LogFileValue> {
  
  int counter = 0;
  
  @Override
  public int getPartition(LogFileKey key, LogFileValue value, int numPartitions) {
    // We don't really care if items with the same key stay together: we
    // just want a sort, with the load spread evenly over the reducers
    counter = ++counter % numPartitions;
    return counter;
  }
}