/**
* 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 com.alimama.quanjingmonitor.kmeans;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapreduce.Mapper;
public class KMeansClusterMapper extends Mapper<WritableComparable<?>, Text, Text, Text> {
ParseVector parse=new ParseVector();
@Override
protected void map(WritableComparable<?> key, Text point, Context context)
throws IOException, InterruptedException {
Cluster nearestCluster = null;
double nearestDistance = Integer.MAX_VALUE;
Vector pointv=parse.parseVector(point.toString());
if(pointv==null)
{
return ;
}
pointv.setNumPoints(1);
for (Cluster cluster : clusters) {
Vector clusterCenter = cluster.getCenter();
boolean isDeny=clusterCenter.Deny(pointv);
if(isDeny)
{
continue;
}
double distance =clusterCenter.distiance(pointv);
context.getCounter("Clustering", "similar").increment(1);
if (distance <= nearestDistance || nearestCluster == null) {
nearestCluster = cluster;
nearestDistance = distance;
}
}
if(nearestCluster!=null)
{
context.write(new Text(String.valueOf(nearestCluster.getId())),new Text(String.valueOf(nearestDistance)+"@abtest@"+point.toString()));
}
}
private final Collection<Cluster> clusters = new ArrayList<Cluster>();
@Override
protected void setup(Context context) throws IOException,
InterruptedException {
super.setup(context);
this.clusters.clear();
Configuration conf = context.getConfiguration();
parse.setup(conf);
try {
String clusterPath = conf.get(KMeansDriver.CLUSTER_PATH_KEY);
if (clusterPath != null && clusterPath.length() > 0) {
KmeansPublic.configureWithClusterInfo(conf, new Path(clusterPath), clusters);
if (clusters.isEmpty()) {
throw new IllegalStateException(
"No clusters found. Check your -c path.");
}
}
} catch (Throwable e) {
throw new IllegalStateException(e);
}
}
}