文章概览：

1、前言

2、Eclipse查看远程hadoop集群文件

3、Eclipse提交远程hadoop集群任务

4、小结

1 前言

　　Hadoop高可用品台搭建完备后，参见《Hadoop高可用平台搭建》，下一步是在集群上跑任务，本文主要讲述Eclipse远程提交hadoop集群任务。

2 Eclipse查看远程hadoop集群文件

2.1 编译hadoop eclipse 插件

　　Hadoop集群文件查看可以通过webUI或hadoop Cmd，为了在Eclipse上方便增删改查集群文件，我们需要编译hadoop eclipse 插件，步骤如下：

　　① 环境准备

　　　　JDK环境配置　　配置JAVA_HOME，并将bin目录配置到path

　　　　ANT环境配置　　配置ANT_HOME，并将bin目录配置到path

　　　　在cmd查看：

　　② 软件准备

　　　　hadoop2x-eclipse-plugin-master　　https://github.com/winghc/hadoop2x-eclipse-plugin

　　　　hadoop-common-2.2.0-bin-master　　https://github.com/srccodes/hadoop-common-2.2.0-bin

　　　　hadoop-2.6.0

　　　　eclipse-jee-luna-SR2-win32-x86_64

　　③ 编译

　　注：软件位置为自己机器上位置，请勿照搬。

E:\>cd E:\hadoop\hadoop2x-eclipse-plugin-master\src\contrib\eclipse-plugin

E:\hadoop\hadoop2x-eclipse-plugin-master\src\contrib\eclipse-plugin>ant jar -Dve

rsion=2.6.0 -Declipse.home=E:\eclipse -Dhadoop.home=E:\hadoop\hadoop-2.6.0
Buildfile: E:\hadoop\hadoop2x-eclipse-plugin-master\src\contrib\eclipse-plugin\b
uild.xml

check-contrib:

init:
     [echo] contrib: eclipse-plugin

init-contrib:

ivy-probe-antlib:

ivy-init-antlib:

ivy-init:
[ivy:configure] :: Ivy 2.1.0 - 20090925235825 :: http://ant.apache.org/ivy/ ::
[ivy:configure] :: loading settings :: file = E:\hadoop\hadoop2x-eclipse-plugin-
master\ivy\ivysettings.xml

ivy-resolve-common:

ivy-retrieve-common:
[ivy:cachepath] DEPRECATED: ‘ivy.conf.file‘ is deprecated, use ‘ivy.settings.fil
e‘ instead
[ivy:cachepath] :: loading settings :: file = E:\hadoop\hadoop2x-eclipse-plugin-
master\ivy\ivysettings.xml

compile:
     [echo] contrib: eclipse-plugin
    [javac] E:\hadoop\hadoop2x-eclipse-plugin-master\src\contrib\eclipse-pluginbuild.xml:76: warning: ‘includeantruntime‘ was not set, defaulting to build.sysc
lasspath=last; set to false for repeatable builds

jar:

BUILD SUCCESSFUL
Total time: 10 seconds

　　　　成功编译，生成如下图：

　　④ 将改文件拷贝到Eclipse中plugins目录下，重启Eclipse会出现：

2.2 配置hadoop选项

　　打开Map/Reduce Locations

　　编辑Map/Reduce配置项：

　　根据上一篇，我们配置用户hadoop，Active HDFS和Active NM位置信息。

　　完成后，就可以在Eclipse中查看HDFS文件信息:

2.3 hdfs简单实例

　　我们编写一个hdfs简单实例，来远程操作hadoop。

 1 package com.diexun.cn.mapred;
 2
 3 import java.io.IOException;
 4 import java.net.URI;
 5 import java.net.URISyntaxException;
 6
 7 import org.apache.hadoop.conf.Configuration;
 8 import org.apache.hadoop.fs.FSDataOutputStream;
 9 import org.apache.hadoop.fs.FileSystem;
10 import org.apache.hadoop.fs.Path;
11
12 public class MR2Test {
13
14     static final String INPUT_PATH = "hdfs://192.168.137.101:9000/hello";
15     static final String OUTPUT_PATH = "hdfs://192.168.137.101:9000/output";
16
17     public static void main(String[] args) throws IOException, URISyntaxException {
18         Configuration conf = new Configuration();
19         final FileSystem fileSystem = FileSystem.get(new URI(INPUT_PATH), conf);
20         final Path outPath = new Path(OUTPUT_PATH);
21         if (fileSystem.exists(outPath)) {
22             fileSystem.delete(outPath, true);
23         }
24
25         FSDataOutputStream fsDataOutputStream = fileSystem.create(new Path(INPUT_PATH));
26         fsDataOutputStream.writeBytes("welcome to here ...");
27     }
28
29 }

　　用Eclipse查看HDFS文件，发现hello文件被修改为“welcome to here ...”。

3 Eclipse提交远程hadoop集群任务

　　正式进入本文的正题，新建一个Map/Reduce Project，会引用很多jar（注：平常我们都是新建Maven项目进行开发，有利于程序迁移及体积，后面的文章会以Maven构建），将自带WordCount实例拷贝到Eclipse，

配置运行参数：(注：填写hdfs集群上路径，本地路径无效)

　　执行，出现线面结果：

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" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z
    at org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Native Method)
    at org.apache.hadoop.io.nativeio.NativeIO$Windows.access(NativeIO.java:557)
    at org.apache.hadoop.fs.FileUtil.canRead(FileUtil.java:977)
    at org.apache.hadoop.util.DiskChecker.checkAccessByFileMethods(DiskChecker.java:187)
    at org.apache.hadoop.util.DiskChecker.checkDirAccess(DiskChecker.java:174)
    at org.apache.hadoop.util.DiskChecker.checkDir(DiskChecker.java:108)
    at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.confChanged(LocalDirAllocator.java:285)
    at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:344)
    at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150)
    at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131)
    at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:115)
    at org.apache.hadoop.mapred.LocalDistributedCacheManager.setup(LocalDistributedCacheManager.java:131)
    at org.apache.hadoop.mapred.LocalJobRunner$Job.<init>(LocalJobRunner.java:163)
    at org.apache.hadoop.mapred.LocalJobRunner.submitJob(LocalJobRunner.java:731)
    at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:536)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1296)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1293)
    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:1628)
    at org.apache.hadoop.mapreduce.Job.submit(Job.java:1293)
    at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1314)
    at WordCount.main(WordCount.java:76)

　　方便后面打印，先添加log4j.properties文件：

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%n
log4j.logger.com.codefutures=INFO

　　根据出错提示，是由于NativeIO.java中return access0(path, desiredAccess.accessRight());导致，此句注，改为返回return true。　

　　修改源码后，在项目里创建和Apache中一样的包，此包会覆盖Apache源码包，如下：

　　再次执行：

 INFO - Job job_local401325246_0001 completed successfully
DEBUG - PrivilegedAction as:wangxiaolong (auth:SIMPLE) from:org.apache.hadoop.mapreduce.Job.getCounters(Job.java:764)
 INFO - Counters: 38
    File System Counters
        FILE: Number of bytes read=16290
        FILE: Number of bytes written=545254
        FILE: Number of read operations=0
        FILE: Number of large read operations=0
        FILE: Number of write operations=0
        HDFS: Number of bytes read=38132
        HDFS: Number of bytes written=6834
        HDFS: Number of read operations=15
        HDFS: Number of large read operations=0
        HDFS: Number of write operations=4
    Map-Reduce Framework
        Map input records=174
        Map output records=1139
        Map output bytes=23459
        Map output materialized bytes=7976
        Input split bytes=99
        Combine input records=1139
        Combine output records=286
        Reduce input groups=286
        Reduce shuffle bytes=7976
        Reduce input records=286
        Reduce output records=286
        Spilled Records=572
        Shuffled Maps =1
        Failed Shuffles=0
        Merged Map outputs=1
        GC time elapsed (ms)=18
        CPU time spent (ms)=0
        Physical memory (bytes) snapshot=0
        Virtual memory (bytes) snapshot=0
        Total committed heap usage (bytes)=468713472
    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=19066
    File Output Format Counters
        Bytes Written=6834

　　确实已经成功执行了，可发现“INFO - Job job_local401325246_0001 completed successfully”，

　　观察http://nns:8088/cluster/apps也没有发现该任务，说明此任务并未提交到集群执行。

　　添加配置文件，如下：

　配置文件直接从集群下载（注：集群中yarn-site.xml配置中“yarn.resourcemanager.ha.id”是有所不同的），该下载哪份配置？

　　由于集群中Active RM是nns，故下载nns中yarn-site.xml配置。执行：

Error: java.lang.RuntimeException: java.lang.ClassNotFoundException: Class com.diexun.cn.mapred.WordCount$TokenizerMapper not found
    at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2074)
    at org.apache.hadoop.mapreduce.task.JobContextImpl.getMapperClass(JobContextImpl.java:186)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:742)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
    at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:163)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628)
    at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)
Caused by: java.lang.ClassNotFoundException: Class com.diexun.cn.mapred.WordCount$TokenizerMapper not found
    at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:1980)
    at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2072)
    ... 8 more

　　没有找到对应的代码文件，我们把代码打包，并设置conf，conf.set("mapred.jar", "**.jar"); 再次执行：

Exception message: /bin/bash: line 0: fg: no job control

Stack trace: ExitCodeException exitCode=1: /bin/bash: line 0: fg: no job control

    at org.apache.hadoop.util.Shell.runCommand(Shell.java:538)
    at org.apache.hadoop.util.Shell.run(Shell.java:455)
    at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:715)
    at org.apache.hadoop.yarn.server.nodemanager.DefaultContainerExecutor.launchContainer(DefaultContainerExecutor.java:211)
    at org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch.call(ContainerLaunch.java:302)
    at org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch.call(ContainerLaunch.java:82)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

　　出现如下错误，是由于平台引起，在hadoop2.2~2.5中需修改源码编译(略)，hadoop2.6已经可以直接添加配置，conf.set("mapreduce.app-submission.cross-platform", "true");或直接到mapred-site.xml中配置。再次执行：

 INFO - Job job_1438912697979_0023 completed successfully
DEBUG - PrivilegedAction as:wangxiaolong (auth:SIMPLE) from:org.apache.hadoop.mapreduce.Job.getCounters(Job.java:764)
DEBUG - IPC Client (1894045259) connection to dn2/192.168.137.104:56327 from wangxiaolong sending #217
DEBUG - IPC Client (1894045259) connection to dn2/192.168.137.104:56327 from wangxiaolong got value #217
DEBUG - Call: getCounters took 139ms
 INFO - Counters: 49
    File System Counters
        FILE: Number of bytes read=149
        FILE: Number of bytes written=325029
        FILE: Number of read operations=0
        FILE: Number of large read operations=0
        FILE: Number of write operations=0
        HDFS: Number of bytes read=255
        HDFS: Number of bytes written=86
        HDFS: Number of read operations=9
        HDFS: Number of large read operations=0
        HDFS: Number of write operations=2
    Job Counters
        Launched map tasks=2
        Launched reduce tasks=1
        Data-local map tasks=2
        Total time spent by all maps in occupied slots (ms)=45308
        Total time spent by all reduces in occupied slots (ms)=9324
        Total time spent by all map tasks (ms)=45308
        Total time spent by all reduce tasks (ms)=9324
        Total vcore-seconds taken by all map tasks=45308
        Total vcore-seconds taken by all reduce tasks=9324
        Total megabyte-seconds taken by all map tasks=46395392
        Total megabyte-seconds taken by all reduce tasks=9547776
    Map-Reduce Framework
        Map input records=3
        Map output records=12
        Map output bytes=119
        Map output materialized bytes=155
        Input split bytes=184
        Combine input records=12
        Combine output records=12
        Reduce input groups=11
        Reduce shuffle bytes=155
        Reduce input records=12
        Reduce output records=11
        Spilled Records=24
        Shuffled Maps =2
        Failed Shuffles=0
        Merged Map outputs=2
        GC time elapsed (ms)=827
        CPU time spent (ms)=4130
        Physical memory (bytes) snapshot=479911936
        Virtual memory (bytes) snapshot=6192558080
        Total committed heap usage (bytes)=261115904
    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=71
    File Output Format Counters
        Bytes Written=86

　　至此，任务已经成功提交至集群执行。

　　有时我们想用我们特定用户去执行任务(注：dfs.permissions.enabled为true时，往往会涉及用户权限问题)，可以在VM arguments中设置，这样任务的提交这就变成了设定者。