如何在win7下的eclipse中调试Hadoop2.2.0的程序

Posted 2023-04-21

参考技术A 下面开始进入正题:

序号 名称 描述

1 eclipse Juno Service Release 4.2的本

2 操作系统 Windows7

3 hadoop的eclipse插件 hadoop-eclipse-plugin-2.2.0.jar

4 hadoop的集群环境 虚拟机Linux的Centos6.5单机伪分布式

5 调试程序 Hellow World
遇到的几个问题如下：
java.io.IOException: Could not locate executable null\bin\winutils.exe in the Hadoop binaries.

解决办法:

在org.apache.hadoop.util.Shell类的checkHadoopHome()方法的返回值里写固定的

本机hadoop的路径，散仙在这里更改如下：

private static String checkHadoopHome()

// first check the Dflag hadoop.home.dir with JVM scope
//System.setProperty("hadoop.home.dir", "...");
String home = System.getProperty("hadoop.home.dir");

// fall back to the system/user-global env variable
if (home == null)
home = System.getenv("HADOOP_HOME");


try
// couldn't find either setting for hadoop's home directory
if (home == null)
throw new IOException("HADOOP_HOME or hadoop.home.dir are not set.");


if (home.startsWith("\"") && home.endsWith("\""))
home = home.substring(1, home.length()-1);


// check that the home setting is actually a directory that exists
File homedir = new File(home);
if (!homedir.isAbsolute() || !homedir.exists() || !homedir.isDirectory())
throw new IOException("Hadoop home directory " + homedir
+ " does not exist, is not a directory, or is not an absolute path.");


home = homedir.getCanonicalPath();

catch (IOException ioe)
if (LOG.isDebugEnabled())
LOG.debug("Failed to detect a valid hadoop home directory", ioe);

home = null;

//固定本机的hadoop地址
home="D:\\hadoop-2.2.0";
return home;


第二个异常，Could not locate executable D:\Hadoop\tar\hadoop-2.2.0\hadoop-2.2.0\bin\winutils.exe in the Hadoop binaries. 找不到win上的执行程序，可以去https://github.com/srccodes/hadoop-common-2.2.0-bin下载bin包，覆盖本机的hadoop跟目录下的bin包即可

第三个异常：
Exception in thread "main" java.lang.IllegalArgumentException: Wrong FS: hdfs://192.168.130.54:19000/user/hmail/output/part-00000, expected: file:///
at org.apache.hadoop.fs.FileSystem.checkPath(FileSystem.java:310)
at org.apache.hadoop.fs.RawLocalFileSystem.pathToFile(RawLocalFileSystem.java:47)
at org.apache.hadoop.fs.RawLocalFileSystem.getFileStatus(RawLocalFileSystem.java:357)
at org.apache.hadoop.fs.FilterFileSystem.getFileStatus(FilterFileSystem.java:245)
at org.apache.hadoop.fs.ChecksumFileSystem$ChecksumFSInputChecker.<init>(ChecksumFileSystem.java:125)
at org.apache.hadoop.fs.ChecksumFileSystem.open(ChecksumFileSystem.java:283)
at org.apache.hadoop.fs.FileSystem.open(FileSystem.java:356)
at com.netease.hadoop.HDFSCatWithAPI.main(HDFSCatWithAPI.java:23)

出现这个异常，一般是HDFS的路径写的有问题，解决办法，拷贝集群上的core-site.xml和hdfs-site.xml文件，放在eclipse的src根目录下即可。

第四个异常：

Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z

出现这个异常，一般是由于HADOOP_HOME的环境变量配置的有问题，在这里散仙特别说明一下，如果想在Win上的eclipse中成功调试Hadoop2.2，就需要在本机的环境变量上，添加如下的环境变量：

（1）在系统变量中，新建HADOOP_HOME变量，属性值为D:\hadoop-2.2.0.也就是本机对应的hadoop目录

(2)在系统变量的Path里，追加%HADOOP_HOME%/bin即可

以上的问题，是散仙在测试遇到的，经过对症下药，我们的eclipse终于可以成功的调试MR程序了，散仙这里的Hellow World源码如下：

package com.qin.wordcount;

import java.io.IOException;

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
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.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

/***
*
* Hadoop2.2.0测试
* 放WordCount的例子
*
* @author qindongliang
*
* hadoop技术交流群： 376932160
*
*
* */
public class MyWordCount

/**
* Mapper
*
* **/
private static class WMapper extends Mapper<LongWritable, Text, Text, IntWritable>

private IntWritable count=new IntWritable(1);
private Text text=new Text();
@Override
protected void map(LongWritable key, Text value,Context context)
throws IOException, InterruptedException
String values[]=value.toString().split("#");
//System.out.println(values[0]+"========"+values[1]);
count.set(Integer.parseInt(values[1]));
text.set(values[0]);
context.write(text,count);





/**
* Reducer
*
* **/
private static class WReducer extends Reducer<Text, IntWritable, Text, Text>

private Text t=new Text();
@Override
protected void reduce(Text key, Iterable<IntWritable> value,Context context)
throws IOException, InterruptedException
int count=0;
for(IntWritable i:value)
count+=i.get();

t.set(count+"");
context.write(key,t);





/**
* 改动一
* (1)shell源码里添加checkHadoopHome的路径
* (2)974行，FileUtils里面
* **/

public static void main(String[] args) throws Exception

// String path1=System.getenv("HADOOP_HOME");
// System.out.println(path1);
// System.exit(0);

JobConf conf=new JobConf(MyWordCount.class);
//Configuration conf=new Configuration();
//conf.set("mapred.job.tracker","192.168.75.130:9001");
//读取person中的数据字段
// conf.setJar("tt.jar");
//注意这行代码放在最前面，进行初始化，否则会报

/**Job任务**/
Job job=new Job(conf, "testwordcount");
job.setJarByClass(MyWordCount.class);
System.out.println("模式： "+conf.get("mapred.job.tracker"));;
// job.setCombinerClass(PCombine.class);

// job.setNumReduceTasks(3);//设置为3
job.setMapperClass(WMapper.class);
job.setReducerClass(WReducer.class);
job.setInputFormatClass(TextInputFormat.class);
job.setOutputFormatClass(TextOutputFormat.class);

job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(IntWritable.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);

String path="hdfs://192.168.46.28:9000/qin/output";
FileSystem fs=FileSystem.get(conf);
Path p=new Path(path);
if(fs.exists(p))
fs.delete(p, true);
System.out.println("输出路径存在，已删除！");

FileInputFormat.setInputPaths(job, "hdfs://192.168.46.28:9000/qin/input");
FileOutputFormat.setOutputPath(job,p );
System.exit(job.waitForCompletion(true) ? 0 : 1);





控制台，打印日志如下：
INFO - Configuration.warnOnceIfDeprecated(840) | mapred.job.tracker is deprecated. Instead, use mapreduce.jobtracker.address
模式： local
输出路径存在，已删除！
INFO - Configuration.warnOnceIfDeprecated(840) | session.id is deprecated. Instead, use dfs.metrics.session-id
INFO - JvmMetrics.init(76) | Initializing JVM Metrics with processName=JobTracker, sessionId=
WARN - JobSubmitter.copyAndConfigureFiles(149) | Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this.
WARN - JobSubmitter.copyAndConfigureFiles(258) | No job jar file set. User classes may not be found. See Job or Job#setJar(String).
INFO - FileInputFormat.listStatus(287) | Total input paths to process : 1
INFO - JobSubmitter.submitJobInternal(394) | number of splits:1
INFO - Configuration.warnOnceIfDeprecated(840) | user.name is deprecated. Instead, use mapreduce.job.user.name
INFO - Configuration.warnOnceIfDeprecated(840) | mapred.output.value.class is deprecated. Instead, use mapreduce.job.output.value.class
INFO - Configuration.warnOnceIfDeprecated(840) | mapred.mapoutput.value.class is deprecated. Instead, use mapreduce.map.output.value.class
INFO - Configuration.warnOnceIfDeprecated(840) | mapreduce.map.class is deprecated. Instead, use mapreduce.job.map.class
INFO - Configuration.warnOnceIfDeprecated(840) | mapred.job.name is deprecated. Instead, use mapreduce.job.name
INFO - Configuration.warnOnceIfDeprecated(840) | mapreduce.reduce.class is deprecated. Instead, use mapreduce.job.reduce.class
INFO - Configuration.warnOnceIfDeprecated(840) | mapreduce.inputformat.class is deprecated. Instead, use mapreduce.job.inputformat.class
INFO - Configuration.warnOnceIfDeprecated(840) | mapred.input.dir is deprecated. Instead, use mapreduce.input.fileinputformat.inputdir
INFO - Configuration.warnOnceIfDeprecated(840) | mapred.output.dir is deprecated. Instead, use mapreduce.output.fileoutputformat.outputdir
INFO - Configuration.warnOnceIfDeprecated(840) | mapreduce.outputformat.class is deprecated. Instead, use mapreduce.job.outputformat.class
File System Counters
FILE: Number of bytes read=372
FILE: Number of bytes written=382174
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=76
HDFS: Number of bytes written=27
HDFS: Number of read operations=17
HDFS: Number of large read operations=0
HDFS: Number of write operations=6
Map-Reduce Framework
Map input records=4
Map output records=4
Map output bytes=44
Map output materialized bytes=58
Input split bytes=109
Combine input records=0
Combine output records=0
Reduce input groups=3
Reduce shuffle bytes=0
Reduce input records=4
Reduce output records=3
Spilled Records=8
Shuffled Maps =0
Failed Shuffles=0
Merged Map outputs=0
GC time elapsed (ms)=0
CPU time spent (ms)=0
Physical memory (bytes) snapshot=0
Virtual memory (bytes) snapshot=0
Total committed heap usage (bytes)=532938752
File Input Format Counters
Bytes Read=38
File Output Format Counters
Bytes Written=27

输入的测试数据如下：

中国#1
美国#2
英国#3
中国#2

输出的结果如下：

中国 3
美国 2
英国 3

至此，已经成功的在eclipse里远程调试hadoop成功

[0008] Windows 7 下 eclipse 的hadoop2.6.4 插件安装使用

目的:

基于上篇的方法介绍，开发很不方便 。[0007] windows 下 eclipse 开发 hdfs程序样例 

装上插件，方便后续直接在windows下的IDE开发调试。

环境：

• Linux  Hadoop 2.6.4，参考文章 [0001]
• Win 7 64  下的 Eclipse Version: Luna Service Release 1 (4.4.1)

    工具：

• hadoop-eclipse-plugin-2.6.4.jar   下载地址：http://download.csdn.net/detail/tondayong1981/9437360
• Hadoop 2.6.4 安装程序包, Hadoop2.6.4源码包
• hadoop 2.6 windows插件包    地址后面有

说明:

   以下整个步骤过程是在全部弄好后，才来填补的。中间修改多次，为了快速成文有些内容从其他地方复制。因此，如果完全照着步骤，可能需要一些小修改。整个思路是对的。

1.  准备Hadoop安装包

在windows下解压 Hadoop 2.6.4 安装程序包。  将Linux上的hadoop 安装目录下 etc/hadoop的所有配置文件

全部替换 windows下解压后的配置文件

2 . 安装HDFS eclipse 插件

• eclipse关闭状态下, 将 hadoop-eclipse-plugin-2.6.4.jar 放到该目录下 eclipse安装目录\\plugins\\
• 启动eclipse
• 菜单栏->窗口windows->首选项preferences->Hadoop mapeduce ,指定hadoop路径为前面的解压路径
• 菜单栏->窗口windows->Open Perspective->Other->选择Map/Reduce ok->Map/Reduce Location选项卡 ->右边蓝色小象 打开配置窗口如图,进行如下设置,点击ok

1位置为配置的名称，任意。

2位置为mapred-site.xml文件中的mapreduce.jobhistory.address配置,如果没有则默认是10020。

3位置为core-site.xml文件中的fs.defaultFS：hdfs://ssmaster:9000 。

这是网上找到图片,我的设置 

hadoop2.6伪分布式,ssmaster:10020,ssmaster:9000

 

 

 

设置成功后，在eclipse这里可以直接显示Linux Hadoop hdfs的文件目录

 

可以直接在这里 下载、上传、 删除HDFS上的文件,很方便

 

3  配置Mapreduce Windows 插件包

 3.1  下载hadoop 2.6 windows插件包包

没找到2.6.4的，用2.6的最后也成功了。

其中参考下载地址： http://download.csdn.net/detail/myamor/8393459，这个似乎是win8的， 本人的系统win7，不是从这里下的。 忘记哪里了。可以搜索 winutils.exe + win7 。 下载后的文件应该有 hadoop.dll hadoop.pdb hadoop.lib hadoop.exp winutils.exe winutils.pdb libwinutils.lib

 

 3.2   配置

      a  解压上面的插件包, 将文件全部拷贝到 G:\\RSoftware\\hadoop-2.6.4\\hadoop-2.6.4\\bin ，该路径为前面"2 . 安装HDFS eclipse 插件"的hadoop指定路径。  

      b  设置环境变量

         HADOOP_HOME =G:\\RSoftware\\hadoop-2.6.4\\hadoop-2.6.4

         Path 中添加 G:\\RSoftware\\hadoop-2.6.4\\hadoop-2.6.4\\bin

         确保有 HADOOP_USER_NAME = hadoop   上一篇 [0007]中设置

      

      重启Eclipse ,读取新环境变量

 

4    测试Mapreduce

   4.1 新建mapreduce 工程      

 

完成后项目会自动把Hadoop的所有jar包导入

 

4.2  项目配置log4j

 

在src目录下，创建log4j.properties文件 ，内容如下

log4j.rootLogger=debug,stdout,R
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p - %m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=mapreduce_test.log
log4j.appender.R.MaxFileSize=1MB
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%
log4j.logger.com.codefutures=DEBUG

 

4.3 WordCount类中  添加代码

 

在WordCount项目里右键src新建class，包名com.xxm（请自行命明），类名为WordCount

 

package mp.filetest;

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

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

/**
 * 描述：WordCount explains by xxm
 * @author xxm
 */
public class WordCount2 {

 /**
 * Map类：自己定义map方法
 */
 public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
    /**
    * LongWritable, IntWritable, Text 均是 Hadoop 中实现的用于封装 Java 数据类型的类
    * 都能够被串行化从而便于在分布式环境中进行数据交换，可以将它们分别视为long,int,String 的替代品。
    */
    private final static IntWritable one = new IntWritable(1);
    private Text word = new Text();
    /**
    * Mapper类中的map方法：
    * protected void map(KEYIN key, VALUEIN value, Context context)
    * 映射一个单个的输入k/v对到一个中间的k/v对
    * Context类：收集Mapper输出的<k,v>对。
    */
    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String line = value.toString();
        StringTokenizer tokenizer = new StringTokenizer(line);
        while (tokenizer.hasMoreTokens()) {
            word.set(tokenizer.nextToken());
            context.write(word, one);
        }
    }
 } 

 /**
 * Reduce类：自己定义reduce方法
 */       
 public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable> {

    /**
    * Reducer类中的reduce方法：
    * protected void reduce(KEYIN key, Interable<VALUEIN> value, Context context)
    * 映射一个单个的输入k/v对到一个中间的k/v对
    * Context类：收集Reducer输出的<k,v>对。
    */
    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));
    }
 }

 /**
 * main主函数
 */       
 public static void main(String[] args) throws Exception {

    Configuration conf = new Configuration();//创建一个配置对象，用来实现所有配置

    Job job = new Job(conf, "wordcount2");//新建一个job，并定义名称

    job.setOutputKeyClass(Text.class);//为job的输出数据设置Key类
    job.setOutputValueClass(IntWritable.class);//为job输出设置value类
    
    job.setMapperClass(Map.class); //为job设置Mapper类
    job.setReducerClass(Reduce.class);//为job设置Reduce类
    job.setJarByClass(WordCount2.class);

    job.setInputFormatClass(TextInputFormat.class);//为map-reduce任务设置InputFormat实现类
    job.setOutputFormatClass(TextOutputFormat.class);//为map-reduce任务设置OutputFormat实现类

    FileInputFormat.addInputPath(job, new Path(args[0]));//为map-reduce job设置输入路径
    FileOutputFormat.setOutputPath(job, new Path(args[1]));//为map-reduce job设置输出路径
    job.waitForCompletion(true); //运行一个job，并等待其结束
 }

}

View Code

 

可选， 如果没有配置，最后可能报这个错误,在文章最后面异常部分， 按照异常解决办法配置。

(   Y.2  运行过程中 异常

1 main"java.lang.UnsatisfiedLinkError:org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)

）

 

4.4 运行

确保Hadoop已经启动

在WordCount的代码区域，右键，点击Run As—>Run Configurations，配置运行参数，文件夹输入和输出,第2个参数的路径确保HDFS上不存在
hdfs://ssmaster:9000/input 
hdfs://ssmaster:9000/output  

 

 

点击 Run运行,可以直接在eclipse的控制台看到执行进度和结果

INFO - Job job_local1914346901_0001 completed successfully

  INFO - Counters: 38 
    File System Counters 
        FILE: Number of bytes read=4109 
        FILE: Number of bytes written=1029438 
        FILE: Number of read operations=0 
        FILE: Number of large read operations=0 
        FILE: Number of write operations=0 
        HDFS: Number of bytes read=134 
        HDFS: Number of bytes written=40 
        HDFS: Number of read operations=37 
        HDFS: Number of large read operations=0 
        HDFS: Number of write operations=6 
    Map-Reduce Framework 
        Map input records=3 
        Map output records=7 
        Map output bytes=70 
        Map output materialized bytes=102 
        Input split bytes=354 
        Combine input records=7 
        Combine output records=7 
        Reduce input groups=5 
        Reduce shuffle bytes=102 
        Reduce input records=7 
        Reduce output records=5 
        Spilled Records=14 
        Shuffled Maps =3 
        Failed Shuffles=0 
        Merged Map outputs=3 
        GC time elapsed (ms)=21 
        CPU time spent (ms)=0 
        Physical memory (bytes) snapshot=0 
        Virtual memory (bytes) snapshot=0 
        Total committed heap usage (bytes)=1556611072 
    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=42 
    File Output Format Counters 
        Bytes Written=40

执行日志

在“DFS Locations”下，刷新刚创建的“hadoop”看到本次任务的输出目录下是否有输出文件。

 

 

4.5 可选  命令行下执行,导出成jar包，上传到Linux

右键项目名字->导出->java/jar文件 ->指定jar路径名字->指定main类为   完成

先删除刚才的输出目录

 hadoop@ssmaster:~/java_program$ hadoop fs -rm -r /output

hadoop@ssmaster:~/java_program$ hadoop fs -ls /
Found 4 items
drwxr-xr-x   - hadoop supergroup          0 2016-10-24 05:04 /data
drwxr-xr-x   - hadoop supergroup          0 2016-10-23 00:45 /input
drwxr-xr-x   - hadoop supergroup          0 2016-10-24 05:04 /test
drwx------   - hadoop supergroup          0 2016-10-23 00:05 /tmp

执行 hadoop  jar hadoop_mapr_wordcount.jar  /input /output

hadoop@ssmaster:~/java_program$ hadoop  jar hadoop_mapr_wordcount.jar  /input /output 
16/10/24 08:30:32 INFO client.RMProxy: Connecting to ResourceManager at ssmaster/192.168.249.144:8032
16/10/24 08:30:33 WARN mapreduce.JobResourceUploader: Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this.
16/10/24 08:30:33 INFO input.FileInputFormat: Total input paths to process : 1
16/10/24 08:30:34 INFO mapreduce.JobSubmitter: number of splits:1
16/10/24 08:30:34 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1477315002921_0004
16/10/24 08:30:34 INFO impl.YarnClientImpl: Submitted application application_1477315002921_0004
16/10/24 08:30:34 INFO mapreduce.Job: The url to track the job: http://ssmaster:8088/proxy/application_1477315002921_0004/
16/10/24 08:30:34 INFO mapreduce.Job: Running job: job_1477315002921_0004
16/10/24 08:30:43 INFO mapreduce.Job: Job job_1477315002921_0004 running in uber mode : false
16/10/24 08:30:43 INFO mapreduce.Job:  map 0% reduce 0%
16/10/24 08:30:52 INFO mapreduce.Job:  map 100% reduce 0%
16/10/24 08:31:02 INFO mapreduce.Job:  map 100% reduce 100%
16/10/24 08:31:04 INFO mapreduce.Job: Job job_1477315002921_0004 completed successfully
16/10/24 08:31:05 INFO mapreduce.Job: Counters: 49
    File System Counters
        FILE: Number of bytes read=3581
        FILE: Number of bytes written=220839
        FILE: Number of read operations=0
        FILE: Number of large read operations=0
        FILE: Number of write operations=0
        HDFS: Number of bytes read=1863
        HDFS: Number of bytes written=1425
        HDFS: Number of read operations=6
        HDFS: Number of large read operations=0
        HDFS: Number of write operations=2
    Job Counters 
        Launched map tasks=1
        Launched reduce tasks=1
        Data-local map tasks=1
        Total time spent by all maps in occupied slots (ms)=6483
        Total time spent by all reduces in occupied slots (ms)=7797
        Total time spent by all map tasks (ms)=6483
        Total time spent by all reduce tasks (ms)=7797
        Total vcore-milliseconds taken by all map tasks=6483
        Total vcore-milliseconds taken by all reduce tasks=7797
        Total megabyte-milliseconds taken by all map tasks=6638592
        Total megabyte-milliseconds taken by all reduce tasks=7984128
    Map-Reduce Framework
        Map input records=11
        Map output records=303
        Map output bytes=2969
        Map output materialized bytes=3581
        Input split bytes=101
        Combine input records=0
        Combine output records=0
        Reduce input groups=158
        Reduce shuffle bytes=3581
        Reduce input records=303
        Reduce output records=158
        Spilled Records=606
        Shuffled Maps =1
        Failed Shuffles=0
        Merged Map outputs=1
        GC time elapsed (ms)=241
        CPU time spent (ms)=4530
        Physical memory (bytes) snapshot=456400896
        Virtual memory (bytes) snapshot=1441251328
        Total committed heap usage (bytes)=312999936
    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=1762
    File Output Format Counters 
        Bytes Written=1425

View Code

备注：如何导出包，可以用这种方式执行  hadoop  jar xxxx.jar  wordcount /input /output [遗留]

 

Y 异常

Y.1    Permission denied: user=Administrator

在第2步最后, HDFS的某个目录可能提示：

 Permission denied: user=Administrator, access=WRITE, inode="hadoop": hadoop:supergroup:rwxr-xr-x

用户Administator在hadoop上执行写操作时被权限系统拒,windows eclipse的默认用 用户Administator 去访问hadoop的文件

解决如下：

windows 添加环境变量 HADOOP_USER_NAME ，值为 hadoop (这是Linux上hadoop2.6.4 的用户名)

重启eclipse生效

 

Y.2  运行过程中 异常

1 main"java.lang.UnsatisfiedLinkError:org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z

原因：未知　　

解决：

a  将前面下载的配置包中的 hadoop.dll 文件拷贝到  C:\\Windows\\System32 ，参考中提示需要 重启电脑

b  源码包 hadoop-2.6.4-src.tar.gz解压，hadoop-2.6.4-src\\hadoop-common-project\\hadoop-common\\src\\main\\java\\org\\apache\\hadoop\\io\\nativeio下NativeIO.java 复制到对应的Eclipse的project

       修改如下地方

       

 

2  log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.

log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://ssmaster:9000/output already exists
    at org.apache.hadoop.mapreduce.lib.output.FileOutputFormat.checkOutputSpecs(FileOutputFormat.java:146)
    at org.apache.hadoop.mapreduce.JobSubmitter.checkSpecs(JobSubmitter.java:267)
    at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:140)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1297)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1294)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1656)
    at org.apache.hadoop.mapreduce.Job.submit(Job.java:1294)
    at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1315)
    at mp.filetest.WordCount2.main(WordCount2.java:88)

执行错误日志

原因： log4j.properties文件没有

解决： 照步骤做 4.2

3  Failed to locate the winutils binary in the hadoop binary path
java.io.IOException: Could not locate executable null\\bin\\winutils.exe in the

2016-10-24 20:42:03,603 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2016-10-24 20:42:03,709 ERROR [main] util.Shell (Shell.java:getWinUtilsPath(373)) - Failed to locate the winutils binary in the hadoop binary path
java.io.IOException: Could not locate executable null\\bin\\winutils.exe in the Hadoop binaries.
    at org.apache.hadoop.util.Shell.getQualifiedBinPath(Shell.java:355)
    at org.apache.hadoop.util.Shell.getWinUtilsPath(Shell.java:370)
    at org.apache.hadoop.util.Shell.<clinit>(Shell.java:363)
    at org.apache.hadoop.util.StringUtils.<clinit>(StringUtils.java:79)
    at org.apache.hadoop.security.Groups.parseStaticMapping(Groups.java:116)
    at org.apache.hadoop.security.Groups.<init>(Groups.java:93)
    at org.apache.hadoop.security.Groups.<init>(Groups.java:73)
    at org.apache.hadoop.security.Groups.getUserToGroupsMappingService(Groups.java:293)

View Code

原因：hadoop 2.6 windows插件包没配置好

解决：安装步骤3.2中配置

 

 

Z 总结：

 加油，干得好。

 后续：

  照着参考里面的程序，跑一下，测试直接跑程序能否成功 done

  有空弄明白 log4j.properties配置中各个参数含义

  将Hadoop源码包导入项目中，以便跟踪调试

 

C 参考:

c.1  安装：     Win7+Eclipse+Hadoop2.6.4开发环境搭建 

c.2  安装：     Hadoop学习笔记（4）－Linux ubuntu 下  Eclipse下搭建Hadoop2.6.4开发环境

c.3  错误处理：关于使用Hadoop MR的Eclipse插件开发时遇到Permission denied问题的解决办法 

c.4  错误处理： 解决Exception: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z 等一系列问题