package com.mongodb.hadoop.examples.sensors;
import com.mongodb.hadoop.io.MongoUpdateWritable;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.Reducer;
import org.bson.BasicBSONObject;
import org.bson.types.ObjectId;
import java.io.IOException;
import java.util.Iterator;
public class LogReducer extends Reducer<Text, IntWritable, NullWritable, MongoUpdateWritable>
implements org.apache.hadoop.mapred.Reducer<Text, IntWritable, NullWritable, MongoUpdateWritable> {
private static final Log LOG = LogFactory.getLog(LogReducer.class);
@Override
public void reduce(final Text pKey, final Iterable<IntWritable> pValues, final Context pContext)
throws IOException, InterruptedException {
int count = 0;
for (IntWritable val : pValues) {
count += val.get();
}
BasicBSONObject query = new BasicBSONObject("devices", new ObjectId(pKey.toString()));
BasicBSONObject update = new BasicBSONObject("$inc", new BasicBSONObject("logs_count", count));
LOG.debug("query: " + query);
LOG.debug("update: " + update);
pContext.write(null, new MongoUpdateWritable(query, update, true, false));
}
@Override
public void reduce(final Text key, final Iterator<IntWritable> values, final OutputCollector<NullWritable, MongoUpdateWritable> output,
final Reporter reporter) throws IOException {
int count = 0;
while (values.hasNext()) {
count += values.next().get();
}
BasicBSONObject query = new BasicBSONObject("devices", new ObjectId(key.toString()));
BasicBSONObject update = new BasicBSONObject("$inc", new BasicBSONObject("logs_count", count));
LOG.debug("query: " + query);
LOG.debug("update: " + update);
output.collect(null, new MongoUpdateWritable(query, update, true, false));
}
@Override
public void close() throws IOException {
}
@Override
public void configure(final JobConf job) {
}
}