/**
* 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.
*/
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.CharacterCodingException;
import java.util.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.hadoop.cql3.CqlConfigHelper;
import org.apache.cassandra.hadoop.cql3.CqlPagingInputFormat;
import org.apache.cassandra.hadoop.cql3.CqlInputFormat;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import com.datastax.driver.core.Row;
import org.apache.cassandra.hadoop.ConfigHelper;
import org.apache.cassandra.utils.ByteBufferUtil;
/**
* This sums the word count stored in the input_words_count ColumnFamily for the key "sum".
*
* Output is written to a text file.
*/
public class WordCountCounters extends Configured implements Tool
{
private static final Logger logger = LoggerFactory.getLogger(WordCountCounters.class);
static final String INPUT_MAPPER_VAR = "input_mapper";
static final String COUNTER_COLUMN_FAMILY = "input_words_count";
private static final String OUTPUT_PATH_PREFIX = "/tmp/word_count_counters";
public static void main(String[] args) throws Exception
{
// Let ToolRunner handle generic command-line options
ToolRunner.run(new Configuration(), new WordCountCounters(), args);
System.exit(0);
}
public static class SumNativeMapper extends Mapper<Long, Row, Text, LongWritable>
{
long sum = -1;
public void map(Long key, Row row, Context context) throws IOException, InterruptedException
{
if (sum < 0)
sum = 0;
logger.debug("read " + key + ":count_num from " + context.getInputSplit());
sum += Long.valueOf(row.getString("count_num"));
}
protected void cleanup(Context context) throws IOException, InterruptedException {
if (sum > 0)
context.write(new Text("total_count"), new LongWritable(sum));
}
}
public static class SumMapper extends Mapper<Map<String, ByteBuffer>, Map<String, ByteBuffer>, Text, LongWritable>
{
long sum = -1;
public void map(Map<String, ByteBuffer> key, Map<String, ByteBuffer> columns, Context context) throws IOException, InterruptedException
{
if (sum < 0)
sum = 0;
logger.debug("read " + toString(key) + ":count_num from " + context.getInputSplit());
sum += Long.valueOf(ByteBufferUtil.string(columns.get("count_num")));
}
protected void cleanup(Context context) throws IOException, InterruptedException {
if (sum > 0)
context.write(new Text("total_count"), new LongWritable(sum));
}
private String toString(Map<String, ByteBuffer> keys)
{
String result = "";
try
{
for (ByteBuffer key : keys.values())
result = result + ByteBufferUtil.string(key) + ":";
}
catch (CharacterCodingException e)
{
logger.error("Failed to print keys", e);
}
return result;
}
}
public static class ReducerToFilesystem extends Reducer<Text, LongWritable, Text, LongWritable>
{
long sum = 0;
public void reduce(Text key, Iterable<LongWritable> values, Context context) throws IOException, InterruptedException
{
for (LongWritable val : values)
sum += val.get();
context.write(key, new LongWritable(sum));
}
}
public int run(String[] args) throws Exception
{
String inputMapperType = "native";
if (args != null && args[0].startsWith(INPUT_MAPPER_VAR))
{
String[] arg0 = args[0].split("=");
if (arg0 != null && arg0.length == 2)
inputMapperType = arg0[1];
}
Job job = new Job(getConf(), "wordcountcounters");
job.setCombinerClass(ReducerToFilesystem.class);
job.setReducerClass(ReducerToFilesystem.class);
job.setJarByClass(WordCountCounters.class);
ConfigHelper.setInputInitialAddress(job.getConfiguration(), "localhost");
ConfigHelper.setInputPartitioner(job.getConfiguration(), "Murmur3Partitioner");
ConfigHelper.setInputColumnFamily(job.getConfiguration(), WordCount.KEYSPACE, WordCount.OUTPUT_COLUMN_FAMILY);
CqlConfigHelper.setInputCQLPageRowSize(job.getConfiguration(), "3");
if ("native".equals(inputMapperType))
{
job.setMapperClass(SumNativeMapper.class);
job.setInputFormatClass(CqlInputFormat.class);
CqlConfigHelper.setInputCql(job.getConfiguration(), "select * from " + WordCount.OUTPUT_COLUMN_FAMILY + " where token(word) > ? and token(word) <= ? allow filtering");
}
else
{
job.setMapperClass(SumMapper.class);
job.setInputFormatClass(CqlPagingInputFormat.class);
ConfigHelper.setInputRpcPort(job.getConfiguration(), "9160");
}
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(LongWritable.class);
FileOutputFormat.setOutputPath(job, new Path(OUTPUT_PATH_PREFIX));
job.waitForCompletion(true);
return 0;
}
}