/**
* 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.util.*;
import java.util.Map.Entry;
import org.apache.cassandra.hadoop.cql3.CqlConfigHelper;
import org.apache.cassandra.hadoop.cql3.CqlOutputFormat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.hadoop.cql3.CqlInputFormat;
import org.apache.cassandra.hadoop.ConfigHelper;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.Mapper.Context;
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 java.nio.charset.CharacterCodingException;
/**
* This counts the occurrences of words in ColumnFamily
* cql3_worldcount ( id uuid,
* line text,
* PRIMARY KEY (id))
*
* For each word, we output the total number of occurrences across all body texts.
*
* When outputting to Cassandra, we write the word counts to column family
* output_words ( word text,
* count_num text,
* PRIMARY KEY (word))
* as a {word, count} to columns: word, count_num with a row key of "word sum"
*/
public class WordCount extends Configured implements Tool
{
private static final Logger logger = LoggerFactory.getLogger(WordCount.class);
static final String INPUT_MAPPER_VAR = "input_mapper";
static final String KEYSPACE = "cql3_worldcount";
static final String COLUMN_FAMILY = "inputs";
static final String OUTPUT_REDUCER_VAR = "output_reducer";
static final String OUTPUT_COLUMN_FAMILY = "output_words";
private static final String OUTPUT_PATH_PREFIX = "/tmp/word_count";
private static final String PRIMARY_KEY = "row_key";
public static void main(String[] args) throws Exception
{
// Let ToolRunner handle generic command-line options
ToolRunner.run(new Configuration(), new WordCount(), args);
System.exit(0);
}
public static class TokenizerMapper extends Mapper<Map<String, ByteBuffer>, Map<String, ByteBuffer>, Text, IntWritable>
{
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
private ByteBuffer sourceColumn;
protected void setup(org.apache.hadoop.mapreduce.Mapper.Context context)
throws IOException, InterruptedException
{
}
public void map(Map<String, ByteBuffer> keys, Map<String, ByteBuffer> columns, Context context) throws IOException, InterruptedException
{
for (Entry<String, ByteBuffer> column : columns.entrySet())
{
if (!"line".equalsIgnoreCase(column.getKey()))
continue;
String value = ByteBufferUtil.string(column.getValue());
StringTokenizer itr = new StringTokenizer(value);
while (itr.hasMoreTokens())
{
word.set(itr.nextToken());
context.write(word, one);
}
}
}
}
public static class NativeTokenizerMapper extends Mapper<Long, Row, Text, IntWritable>
{
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
private ByteBuffer sourceColumn;
protected void setup(org.apache.hadoop.mapreduce.Mapper.Context context)
throws IOException, InterruptedException
{
}
public void map(Long key, Row row, Context context) throws IOException, InterruptedException
{
String value = row.getString("line");
logger.debug("read {}:{}={} from {}", new Object[] {key, "line", value, context.getInputSplit()});
StringTokenizer itr = new StringTokenizer(value);
while (itr.hasMoreTokens())
{
word.set(itr.nextToken());
context.write(word, one);
}
}
}
public static class ReducerToFilesystem extends Reducer<Text, IntWritable, Text, IntWritable>
{
public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException
{
int sum = 0;
for (IntWritable val : values)
sum += val.get();
context.write(key, new IntWritable(sum));
}
}
public static class ReducerToCassandra extends Reducer<Text, IntWritable, Map<String, ByteBuffer>, List<ByteBuffer>>
{
private Map<String, ByteBuffer> keys;
private ByteBuffer key;
protected void setup(org.apache.hadoop.mapreduce.Reducer.Context context)
throws IOException, InterruptedException
{
keys = new LinkedHashMap<String, ByteBuffer>();
}
public void reduce(Text word, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException
{
int sum = 0;
for (IntWritable val : values)
sum += val.get();
keys.put("word", ByteBufferUtil.bytes(word.toString()));
context.write(keys, getBindVariables(word, sum));
}
private List<ByteBuffer> getBindVariables(Text word, int sum)
{
List<ByteBuffer> variables = new ArrayList<ByteBuffer>();
variables.add(ByteBufferUtil.bytes(String.valueOf(sum)));
return variables;
}
}
public int run(String[] args) throws Exception
{
String outputReducerType = "filesystem";
String inputMapperType = "native";
String outputReducer = null;
String inputMapper = null;
if (args != null)
{
if(args[0].startsWith(OUTPUT_REDUCER_VAR))
outputReducer = args[0];
if(args[0].startsWith(INPUT_MAPPER_VAR))
inputMapper = args[0];
if (args.length == 2)
{
if(args[1].startsWith(OUTPUT_REDUCER_VAR))
outputReducer = args[1];
if(args[1].startsWith(INPUT_MAPPER_VAR))
inputMapper = args[1];
}
}
if (outputReducer != null)
{
String[] s = outputReducer.split("=");
if (s != null && s.length == 2)
outputReducerType = s[1];
}
logger.info("output reducer type: " + outputReducerType);
if (inputMapper != null)
{
String[] s = inputMapper.split("=");
if (s != null && s.length == 2)
inputMapperType = s[1];
}
Job job = new Job(getConf(), "wordcount");
job.setJarByClass(WordCount.class);
if (outputReducerType.equalsIgnoreCase("filesystem"))
{
job.setCombinerClass(ReducerToFilesystem.class);
job.setReducerClass(ReducerToFilesystem.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileOutputFormat.setOutputPath(job, new Path(OUTPUT_PATH_PREFIX));
}
else
{
job.setReducerClass(ReducerToCassandra.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(IntWritable.class);
job.setOutputKeyClass(Map.class);
job.setOutputValueClass(List.class);
job.setOutputFormatClass(CqlOutputFormat.class);
ConfigHelper.setOutputColumnFamily(job.getConfiguration(), KEYSPACE, OUTPUT_COLUMN_FAMILY);
job.getConfiguration().set(PRIMARY_KEY, "word,sum");
String query = "UPDATE " + KEYSPACE + "." + OUTPUT_COLUMN_FAMILY +
" SET count_num = ? ";
CqlConfigHelper.setOutputCql(job.getConfiguration(), query);
ConfigHelper.setOutputInitialAddress(job.getConfiguration(), "localhost");
ConfigHelper.setOutputPartitioner(job.getConfiguration(), "Murmur3Partitioner");
}
if (inputMapperType.equalsIgnoreCase("native"))
{
job.setMapperClass(NativeTokenizerMapper.class);
job.setInputFormatClass(CqlInputFormat.class);
CqlConfigHelper.setInputCql(job.getConfiguration(), "select * from " + COLUMN_FAMILY + " where token(id) > ? and token(id) <= ? allow filtering");
}
else
{
job.setMapperClass(TokenizerMapper.class);
job.setInputFormatClass(CqlInputFormat.class);
ConfigHelper.setInputRpcPort(job.getConfiguration(), "9160");
}
ConfigHelper.setInputInitialAddress(job.getConfiguration(), "localhost");
ConfigHelper.setInputColumnFamily(job.getConfiguration(), KEYSPACE, COLUMN_FAMILY);
ConfigHelper.setInputPartitioner(job.getConfiguration(), "Murmur3Partitioner");
CqlConfigHelper.setInputCQLPageRowSize(job.getConfiguration(), "3");
job.waitForCompletion(true);
return 0;
}
}