对于Hadoop的MapReduce编程makefile[通俗易懂]

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根据近期需要hadoop的MapReduce程序集成到一个大的应用C/C++书面框架。在需求make当自己主动MapReduce编译和打包的应用。

在这里，一个简单的WordCount1一个例子详细的实施细则，注意：hadoop版本号2.4.0.

源码包括两个文件。一个是WordCount1.java是详细的对单词计数实现的逻辑。第二个是CounterThread.java。当中简单的当前处理的行数做一个统计和打印。代码分别见附1. 编写makefile的关键是将hadoop提供的jar包的路径所有载入进来，看到网上非常多资料都自己实现一个脚本把hadoop文件夹下所有的.jar文件放到一个路径中。然后进行编译。这样的做法太麻烦了。当然也有些简单的办法，可是都是比較老的hadoop版本号如0.20之类的。

事实上，hadoop提供了一个命令hadoop classpath能够获得包括全部jar包的路径.所以仅仅须要用 javac -classpath “`hadoop classpath`” *.java 便可。然后使用jar -cvf对class文件进行打包就能够了。

详细的Makefile代码例如以下：

SRC_DIR = src/mypackage/*.java 
CLASS_DIR = bin
TARGET_JAR = WordCount

all:$(TARGET_JAR)

$(TARGET_JAR): $(SRC_DIR) 
	mkdir -p $(CLASS_DIR)
#	javac -classpath `$(HADOOP) classpath` -d $(CLASS_DIR) $(SRC_DIR) 
	javac -classpath "`hadoop classpath`" src/mypackage/*.java -d $(CLASS_DIR) -Xlint
	jar -cvf $(TARGET_JAR).jar -C $(CLASS_DIR) ./
 
clean: 
	rm -rf $(CLASS_DIR) *.jar

make一下：

lichao@ubuntu:WordCount1$ make
mkdir -p bin
javac -classpath "`hadoop classpath`" src/mypackage/*.java -d bin -Xlint
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/common/lib/jaxb-api.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/common/lib/activation.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/common/lib/jsr173_1.0_api.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/common/lib/jaxb1-impl.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/yarn/lib/jaxb-api.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/yarn/lib/activation.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/yarn/lib/jsr173_1.0_api.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/share/hadoop/yarn/lib/jaxb1-impl.jar": no such file or directory
warning: [path] bad path element "/home/lichao/Software/hadoop/hadoop-src/hadoop-2.4.0-src/hadoop-dist/target/hadoop-2.4.0/contrib/capacity-scheduler/*.jar": no such file or directory
src/mypackage/WordCount1.java:61: warning: [deprecation] Job(Configuration,String) in Job has been deprecated
		Job job = new Job(conf, "WordCount1");                  //建立新job
		          ^
10 warnings
jar -cvf WordCount.jar -C bin ./
added manifest
adding: mypackage/(in = 0) (out= 0)(stored 0%)
adding: mypackage/WordCount1.class(in = 1970) (out= 1037)(deflated 47%)
adding: mypackage/CounterThread.class(in = 1760) (out= 914)(deflated 48%)
adding: mypackage/WordCount1$IntSumReducer.class(in = 1762) (out= 749)(deflated 57%)
adding: mypackage/WordCount1$TokenizerMapper.class(in = 1759) (out= 762)(deflated 56%)
adding: log4j.properties(in = 476) (out= 172)(deflated 63%)

尽管有warning，可是不影响结果。

编译后。我们来简单的測试一下。

先生成測试数据：while true; do seq 1 100000 >> tmpfile; done; 差点儿相同能够了就Ctrl+c

然后将数据放到hdfs上。hadoop fs -put tmpfile /data/

接着执行MapReduce程序：hadoop jar WordCount.jar mypackage/WordCount1 /data/tmpfile /output2

效果例如以下：

14/07/15 13:26:01 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
14/07/15 13:26:03 INFO client.RMProxy: Connecting to ResourceManager at localhost/127.0.0.1:8032
14/07/15 13:26:05 INFO input.FileInputFormat: Total input paths to process : 1
14/07/15 13:26:05 INFO mapreduce.JobSubmitter: number of splits:6
14/07/15 13:26:06 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1405397597558_0003
14/07/15 13:26:06 INFO impl.YarnClientImpl: Submitted application application_1405397597558_0003
14/07/15 13:26:06 INFO mapreduce.Job: The url to track the job: http://ubuntu:8088/proxy/application_1405397597558_0003/
14/07/15 13:26:06 INFO mapreduce.Job: Running job: job_1405397597558_0003
14/07/15 13:26:20 INFO mapreduce.Job: Job job_1405397597558_0003 running in uber mode : false
14/07/15 13:26:20 INFO mapreduce.Job:  map 0% reduce 0%
14/07/15 13:26:34 WARN mapreduce.Counters: Group org.apache.hadoop.mapred.Task$Counter is deprecated. Use org.apache.hadoop.mapreduce.TaskCounter instead
输入行数：0
14/07/15 13:26:48 INFO mapreduce.Job:  map 2% reduce 0%
输入行数：3138474
14/07/15 13:26:51 INFO mapreduce.Job:  map 5% reduce 0%
14/07/15 13:26:54 INFO mapreduce.Job:  map 6% reduce 0%
14/07/15 13:26:55 INFO mapreduce.Job:  map 8% reduce 0%
14/07/15 13:26:57 INFO mapreduce.Job:  map 9% reduce 0%
14/07/15 13:26:58 INFO mapreduce.Job:  map 11% reduce 0%
14/07/15 13:27:00 INFO mapreduce.Job:  map 12% reduce 0%
14/07/15 13:27:01 INFO mapreduce.Job:  map 13% reduce 0%
输入行数：23383595
14/07/15 13:27:05 INFO mapreduce.Job:  map 14% reduce 0%
输入行数：23383595
14/07/15 13:27:23 INFO mapreduce.Job:  map 15% reduce 0%
14/07/15 13:27:27 INFO mapreduce.Job:  map 16% reduce 0%
14/07/15 13:27:28 INFO mapreduce.Job:  map 18% reduce 0%
14/07/15 13:27:30 INFO mapreduce.Job:  map 19% reduce 0%
14/07/15 13:27:31 INFO mapreduce.Job:  map 21% reduce 0%
14/07/15 13:27:34 INFO mapreduce.Job:  map 24% reduce 0%
输入行数：38430301
14/07/15 13:27:37 INFO mapreduce.Job:  map 25% reduce 0%
14/07/15 13:27:40 INFO mapreduce.Job:  map 26% reduce 0%
输入行数：42826322
14/07/15 13:27:57 INFO mapreduce.Job:  map 27% reduce 0%
14/07/15 13:28:00 INFO mapreduce.Job:  map 29% reduce 0%
14/07/15 13:28:02 INFO mapreduce.Job:  map 30% reduce 0%
14/07/15 13:28:03 INFO mapreduce.Job:  map 32% reduce 0%
输入行数：54513531
14/07/15 13:28:05 INFO mapreduce.Job:  map 33% reduce 0%
14/07/15 13:28:06 INFO mapreduce.Job:  map 34% reduce 0%
14/07/15 13:28:08 INFO mapreduce.Job:  map 35% reduce 0%
14/07/15 13:28:09 INFO mapreduce.Job:  map 36% reduce 0%
输入行数：60959081
14/07/15 13:28:22 INFO mapreduce.Job:  map 42% reduce 0%
14/07/15 13:28:30 INFO mapreduce.Job:  map 43% reduce 0%
14/07/15 13:28:31 INFO mapreduce.Job:  map 44% reduce 0%
14/07/15 13:28:34 INFO mapreduce.Job:  map 45% reduce 0%
14/07/15 13:28:35 INFO mapreduce.Job:  map 46% reduce 0%
输入行数：69936159
14/07/15 13:28:37 INFO mapreduce.Job:  map 47% reduce 0%
14/07/15 13:28:38 INFO mapreduce.Job:  map 48% reduce 0%
14/07/15 13:28:41 INFO mapreduce.Job:  map 49% reduce 0%
14/07/15 13:28:44 INFO mapreduce.Job:  map 50% reduce 0%
输入行数：77160461
14/07/15 13:29:01 INFO mapreduce.Job:  map 51% reduce 0%
14/07/15 13:29:04 INFO mapreduce.Job:  map 52% reduce 0%
14/07/15 13:29:05 INFO mapreduce.Job:  map 53% reduce 0%
输入行数：83000373
14/07/15 13:29:07 INFO mapreduce.Job:  map 54% reduce 0%
14/07/15 13:29:09 INFO mapreduce.Job:  map 55% reduce 0%
14/07/15 13:29:10 INFO mapreduce.Job:  map 56% reduce 0%
14/07/15 13:29:13 INFO mapreduce.Job:  map 57% reduce 0%
14/07/15 13:29:16 INFO mapreduce.Job:  map 58% reduce 0%
输入行数：93361766
14/07/15 13:29:32 INFO mapreduce.Job:  map 59% reduce 0%
输入行数：98194696
14/07/15 13:29:35 INFO mapreduce.Job:  map 60% reduce 0%
14/07/15 13:29:37 INFO mapreduce.Job:  map 61% reduce 0%
14/07/15 13:29:38 INFO mapreduce.Job:  map 62% reduce 0%
14/07/15 13:29:40 INFO mapreduce.Job:  map 63% reduce 0%
14/07/15 13:29:41 INFO mapreduce.Job:  map 64% reduce 0%
14/07/15 13:29:44 INFO mapreduce.Job:  map 65% reduce 0%
14/07/15 13:29:48 INFO mapreduce.Job:  map 66% reduce 0%
输入行数：109562184
14/07/15 13:30:04 INFO mapreduce.Job:  map 67% reduce 0%
输入行数：113362818
14/07/15 13:30:06 INFO mapreduce.Job:  map 68% reduce 0%
14/07/15 13:30:08 INFO mapreduce.Job:  map 69% reduce 0%
14/07/15 13:30:10 INFO mapreduce.Job:  map 70% reduce 0%
14/07/15 13:30:12 INFO mapreduce.Job:  map 71% reduce 0%
14/07/15 13:30:15 INFO mapreduce.Job:  map 72% reduce 0%
输入行数：123074119
14/07/15 13:30:32 INFO mapreduce.Job:  map 76% reduce 0%
14/07/15 13:30:33 INFO mapreduce.Job:  map 80% reduce 0%
14/07/15 13:30:34 INFO mapreduce.Job:  map 83% reduce 0%
14/07/15 13:30:35 INFO mapreduce.Job:  map 84% reduce 0%
输入行数：123074119
14/07/15 13:30:37 INFO mapreduce.Job:  map 89% reduce 0%
14/07/15 13:30:38 INFO mapreduce.Job:  map 92% reduce 0%
14/07/15 13:30:39 INFO mapreduce.Job:  map 95% reduce 0%
14/07/15 13:30:40 INFO mapreduce.Job:  map 100% reduce 0%
输入行数：123074119
14/07/15 13:30:53 INFO mapreduce.Job:  map 100% reduce 100%
14/07/15 13:30:53 INFO mapreduce.Job: Job job_1405397597558_0003 completed successfully
14/07/15 13:30:53 INFO mapreduce.Job: Counters: 50
	File System Counters
		FILE: Number of bytes read=58256119
		FILE: Number of bytes written=66039749
		FILE: Number of read operations=0
		FILE: Number of large read operations=0
		FILE: Number of write operations=0
		HDFS: Number of bytes read=724520133
		HDFS: Number of bytes written=1088895
		HDFS: Number of read operations=21
		HDFS: Number of large read operations=0
		HDFS: Number of write operations=2
	Job Counters 
		Killed map tasks=2
		Launched map tasks=8
		Launched reduce tasks=1
		Data-local map tasks=8
		Total time spent by all maps in occupied slots (ms)=1528715
		Total time spent by all reduces in occupied slots (ms)=17508
		Total time spent by all map tasks (ms)=1528715
		Total time spent by all reduce tasks (ms)=17508
		Total vcore-seconds taken by all map tasks=1528715
		Total vcore-seconds taken by all reduce tasks=17508
		Total megabyte-seconds taken by all map tasks=1565404160
		Total megabyte-seconds taken by all reduce tasks=17928192
	Map-Reduce Framework
		Map input records=123074119
		Map output records=123074119
		Map output bytes=1216795535
		Map output materialized bytes=7133406
		Input split bytes=594
		Combine input records=127374119
		Combine output records=4900000
		Reduce input groups=100000
		Reduce shuffle bytes=7133406
		Reduce input records=600000
		Reduce output records=100000
		Spilled Records=5500000
		Shuffled Maps =6
		Failed Shuffles=0
		Merged Map outputs=6
		GC time elapsed (ms)=39761
		CPU time spent (ms)=1397060
		Physical memory (bytes) snapshot=1797943296
		Virtual memory (bytes) snapshot=5082316800
		Total committed heap usage (bytes)=1398800384
	Shuffle Errors
		BAD_ID=0
		CONNECTION=0
		IO_ERROR=0
		WRONG_LENGTH=0
		WRONG_MAP=0
		WRONG_REDUCE=0
	File Input Format Counters 
		Bytes Read=724519539
	File Output Format Counters 
		Bytes Written=1088895

附录1：WordCount1.java和CounterThread.java的代码

//WordCount1.java代码

package mypackage;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
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.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

public class WordCount1 {
	public static class TokenizerMapper extends Mapper<Object, Text, Text, IntWritable>{

		private final static IntWritable one = new IntWritable(1);  //建立"int"型变量one,初值为1
		private Text word = new Text();                             //建立"string:型变量 word,用于接收传入的单词

		public void map(Object key, Text value, Context context
				) throws IOException, InterruptedException {
			StringTokenizer itr = new StringTokenizer(value.toString());  //将输入的文本按行分段
			while (itr.hasMoreTokens()) {
				word.set(itr.nextToken());                                  //为word赋值
				context.write(word, one);                                   // 将 键-值 对 word one 传入
			}
			//System.out.println("read lines:"+context.getCounter("org.apache.hadoop.mapred.Task$Counter","MAP_INPUT_RECORDS").getValue());
			//System.out.println( "输入行数：" + context.getCounters().findCounter("org.apache.hadoop.mapred.Task$Counter", "MAP_INPUT_RECORDS").getValue() );
			//System.out.println( "输入行数：" + context.getCounters().findCounter("", "MAP_INPUT_RECORDS").getValue() );
		}
	}

	public static class IntSumReducer 
	extends Reducer<Text,IntWritable,Text,IntWritable> { 
		private IntWritable result = new IntWritable();                 //创建整型变量result

		public void reduce(Text key, Iterable<IntWritable> values, 
				Context context
				) throws IOException, InterruptedException {
			int sum = 0;                                                 //创建int 型变量sum 初值0
			for (IntWritable val : values) {
				sum += val.get();                                          //将每一个key相应的全部value类间

			}
			result.set(sum);                                              //sum传入result                                        
			context.write(key, result);                                   //将 key-result对传入
		}
	}

	public static void main(String[] args) throws Exception {
		Configuration conf = new Configuration();
		//String[] newArgs = new String[]{"hdfs://localhost:9000/data/tmpfile","hdfs://localhost:9000/data/wc_output"};
		String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
		if (otherArgs.length != 2) {
			System.err.println("Usage: wordcount <in> <out>");
			System.exit(2);
		}
		Job job = new Job(conf, "WordCount1");                  //建立新job
		job.setJarByClass(WordCount1.class);
		job.setMapperClass(TokenizerMapper.class);              //设置map类
		job.setCombinerClass(IntSumReducer.class);              //设置combiner类
		job.setReducerClass(IntSumReducer.class);               //设置reducer类
		job.setOutputKeyClass(Text.class);                       //输出的key类型
		job.setOutputValueClass(IntWritable.class);              //输出的value类型
		FileInputFormat.addInputPath(job, new Path(otherArgs[0]));  //输入输出參数(在设置中指定)
		FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
		
		CounterThread ct = new CounterThread(job);
		ct.start();
		
		job.waitForCompletion(true);
		
		System.exit(0);
		//System.exit(job.waitForCompletion(true) ? 0 : 1);
	}
}

//CounterThread.java的代码

package mypackage;

import java.lang.*;
import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
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.JobStatus;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

public class CounterThread extends Thread{
	
	public CounterThread(Job job) {
		_job = job;
	}
	
	public void run() {
		while(true){
			try {
				Thread.sleep(1000*5);
			} catch (InterruptedException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			try {
				if(_job.getStatus().getState() == JobStatus.State.RUNNING) 
					//continue;
					System.out.println( "输入行数：" + _job.getCounters().findCounter("org.apache.hadoop.mapred.Task$Counter", "MAP_INPUT_RECORDS").getValue() );
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	private Job _job;
}

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