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Hadoop学习笔记（二）设置单节点集群

2024-07-25 21:20:12   222人阅读

本文描述如何设置一个单一节点的 Hadoop 安装，以便您可以快速执行简单的操作，使用 Hadoop MapReduce 和 Hadoop 分布式文件系统 (HDFS)。

参考官方文档：Hadoop MapReduce Next Generation - Setting up a Single Node Cluster.

Hadoop版本：Apache Hadoop 2.5.1

系统版本：CentOS 6.5，内核（uname -r）：2.6.32-431.el6.x86_64

系统必备组件

支持的系统平台

GNU/Linux 作为开发和生产的平台，毫无疑问。Windows 也是受支持的平台，但是以下步骤仅用于 Linux。

依赖的软件

在Linux系统上安装所需要的软件包

1、JAVA（JDK）必须安装，推荐的版本请参考Hadoop JAVA Version，我这里安装的是1.7。

2、ssh 必须安装，必须运行 sshd 才能使用管理远程 Hadoop 守护程序的 Hadoop 脚本。

安装依赖的软件

如果您的系统没有所需的软件，您将需要安装它。

例如在Ubuntu Linux上使用以下命令:

  $ sudo apt-get install ssh
  $ sudo apt-get install rsync

CentOS应该是即使是最小安装也带了ssh（Secure Shell），刚开始我给弄混了，以为是JAVA的SSH（Spring + Struts +Hibernate），汗！尴尬

安装JDK，参考：CentOS下安装JDK7

下载

就不多说了，上一篇下过了。链接：Hadoop学习笔记（一）从官网下载安装包

准备启动 Hadoop 集群

解压文件hadoop-2.5.1.tar.gz，执行：tar xvf hadoop-2.5.1.tar.gz，会将文件解压到hadoop-2.5.1目录下；

切换目录:cd hadoop-2.5.1/etc/hadoop/

编辑“hadoop-env.sh”文件，添加参考定义；

vi hadoop-env.sh

个人觉得比较好的习惯是编辑文件之前先做个备份（cp hadoop-env.sh hadoop-env.sh.bak）；

找到以下位置：

# The java implementation to use.
export JAVA_HOME={JAVA_HOME}
将其改为：

# The java implementation to use.
export JAVA_HOME=/usr/java/latest
在下面再添加一句：

# Assuming your installation directory is /usr/local/hadoop
export HADOOP_PREFIX=/usr/local/hadoop
保存并退出，ESC,:wq

切换目录（cd ../..），返回“/opt/hadoop-2.5.1”；

尝试执行以下命令：

 ./bin/hadoop

这将显示 hadoop 脚本的使用文档，输出如下：

Usage: hadoop [--config confdir] COMMAND
       where COMMAND is one of:
  fs                   run a generic filesystem user client
  version              print the version
  jar <jar>            run a jar file
  checknative [-a|-h]  check native hadoop and compression libraries availability
  distcp <srcurl> <desturl> copy file or directories recursively
  archive -archiveName NAME -p <parent path> <src>* <dest> create a hadoop archive
  classpath            prints the class path needed to get the
                       Hadoop jar and the required libraries
  daemonlog            get/set the log level for each daemon
 or
  CLASSNAME            run the class named CLASSNAME

Most commands print help when invoked w/o parameters.
你现在准备好开始您的 Hadoop 集群三个受支持的模式之一：
  • 本地 （独立） 模式
  • 伪分布的模式
  • 完全分布式模式

本地模式操作方法

默认情况下，Hadoop 被配置为运行在非分布式模式下，作为一个单一的 Java 进程。这比较适合用于调试。
下面的示例复制要使用作为输入的解压缩的 conf 目录，然后查找并显示给定正则表达式的每一场比赛。输出被写入给定的输出目录。

  $ mkdir input
  $ cp etc/hadoop/*.xml input
  $ bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.5.1.jar grep input output ‘dfs[a-z.]+‘
  $ cat output/*

执行“bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.5.1.jar grep input output ‘dfs[a-z.]+‘”时

却出现错误：Error: Could not find or load main class org.apache.hadoop.util.RunJar

此问题只在Stack Overflow上见到

What does “Error: Could not find or load main class org.apache.hadoop.util.RunJar”?

但是也没能找到解决的办法；还是自己摸索吧！

解决步骤：

刚刚备份的“hadoop-env.sh”文件现在用上了，还原它。

再执行“bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.5.1.jar grep input output ‘dfs[a-z.]+‘”，

提示：

./bin/hadoop: line 133: /usr/java/jdk1.7.0/bin/java: No such file or directory
./bin/hadoop: line 133: exec: /usr/java/jdk1.7.0/bin/java: cannot execute: No such file or directory
按提示应该还是JAVA（JDK）的安装的问题，我安装JDK的时候只执行到
rpm -ivh /目录/jdk-7-linux-x64.rpm

再没执行其它操作，将后续的步骤执行完成后，再执行“bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.5.1.jar grep input output ‘dfs[a-z.]+‘”，

输出：

14/10/07 03:35:57 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
14/10/07 03:35:58 INFO Configuration.deprecation: session.id is deprecated. Instead, use dfs.metrics.session-id
14/10/07 03:35:58 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=
14/10/07 03:35:59 WARN mapreduce.JobSubmitter: No job jar file set.  User classes may not be found. See Job or Job#setJar(String).
14/10/07 03:35:59 INFO input.FileInputFormat: Total input paths to process : 6
14/10/07 03:35:59 INFO mapreduce.JobSubmitter: number of splits:6
14/10/07 03:36:00 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_local1185570365_0001
14/10/07 03:36:00 WARN conf.Configuration: file:/tmp/hadoop-root/mapred/staging/root1185570365/.staging/job_local1185570365_0001/job.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval;  Ignoring.
14/10/07 03:36:01 WARN conf.Configuration: file:/tmp/hadoop-root/mapred/staging/root1185570365/.staging/job_local1185570365_0001/job.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.attempts;  Ignoring.
14/10/07 03:36:01 WARN conf.Configuration: file:/tmp/hadoop-root/mapred/local/localRunner/root/job_local1185570365_0001/job_local1185570365_0001.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval;  Ignoring.
14/10/07 03:36:01 WARN conf.Configuration: file:/tmp/hadoop-root/mapred/local/localRunner/root/job_local1185570365_0001/job_local1185570365_0001.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.attempts;  Ignoring.
14/10/07 03:36:01 INFO mapreduce.Job: The url to track the job: http://localhost:8080/
14/10/07 03:36:01 INFO mapreduce.Job: Running job: job_local1185570365_0001
14/10/07 03:36:01 INFO mapred.LocalJobRunner: OutputCommitter set in config null
14/10/07 03:36:01 INFO mapred.LocalJobRunner: OutputCommitter is org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter
14/10/07 03:36:02 INFO mapred.LocalJobRunner: Waiting for map tasks
14/10/07 03:36:02 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_m_000000_0
14/10/07 03:36:02 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:02 INFO mapred.MapTask: Processing split: file:/opt/hadoop-2.5.1/input/hadoop-policy.xml:0+9201
14/10/07 03:36:02 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
14/10/07 03:36:02 INFO mapred.MapTask: (EQUATOR) 0 kvi 26214396(104857584)
14/10/07 03:36:02 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 100
14/10/07 03:36:02 INFO mapred.MapTask: soft limit at 83886080
14/10/07 03:36:02 INFO mapred.MapTask: bufstart = 0; bufvoid = 104857600
14/10/07 03:36:02 INFO mapred.MapTask: kvstart = 26214396; length = 6553600
14/10/07 03:36:02 INFO mapred.LocalJobRunner: 
14/10/07 03:36:02 INFO mapred.MapTask: Starting flush of map output
14/10/07 03:36:02 INFO mapred.MapTask: Spilling map output
14/10/07 03:36:02 INFO mapred.MapTask: bufstart = 0; bufend = 17; bufvoid = 104857600
14/10/07 03:36:02 INFO mapred.MapTask: kvstart = 26214396(104857584); kvend = 26214396(104857584); length = 1/6553600
14/10/07 03:36:02 INFO mapreduce.Job: Job job_local1185570365_0001 running in uber mode : false
14/10/07 03:36:02 INFO mapred.MapTask: Finished spill 0
14/10/07 03:36:02 INFO mapreduce.Job:  map 0% reduce 0%
14/10/07 03:36:02 INFO mapred.Task: Task:attempt_local1185570365_0001_m_000000_0 is done. And is in the process of committing
14/10/07 03:36:02 INFO mapred.LocalJobRunner: map
14/10/07 03:36:02 INFO mapred.Task: Task ‘attempt_local1185570365_0001_m_000000_0‘ done.
14/10/07 03:36:02 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_m_000000_0
14/10/07 03:36:02 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_m_000001_0
14/10/07 03:36:02 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:02 INFO mapred.MapTask: Processing split: file:/opt/hadoop-2.5.1/input/capacity-scheduler.xml:0+3589
14/10/07 03:36:02 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
14/10/07 03:36:02 INFO mapred.MapTask: (EQUATOR) 0 kvi 26214396(104857584)
14/10/07 03:36:02 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 100
14/10/07 03:36:02 INFO mapred.MapTask: soft limit at 83886080
14/10/07 03:36:02 INFO mapred.MapTask: bufstart = 0; bufvoid = 104857600
14/10/07 03:36:02 INFO mapred.MapTask: kvstart = 26214396; length = 6553600
14/10/07 03:36:02 INFO mapred.LocalJobRunner: 
14/10/07 03:36:02 INFO mapred.MapTask: Starting flush of map output
14/10/07 03:36:02 INFO mapred.Task: Task:attempt_local1185570365_0001_m_000001_0 is done. And is in the process of committing
14/10/07 03:36:02 INFO mapred.LocalJobRunner: map
14/10/07 03:36:02 INFO mapred.Task: Task ‘attempt_local1185570365_0001_m_000001_0‘ done.
14/10/07 03:36:02 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_m_000001_0
14/10/07 03:36:02 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_m_000002_0
14/10/07 03:36:02 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:02 INFO mapred.MapTask: Processing split: file:/opt/hadoop-2.5.1/input/hdfs-site.xml:0+775
14/10/07 03:36:02 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
14/10/07 03:36:03 INFO mapred.MapTask: (EQUATOR) 0 kvi 26214396(104857584)
14/10/07 03:36:03 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 100
14/10/07 03:36:03 INFO mapred.MapTask: soft limit at 83886080
14/10/07 03:36:03 INFO mapred.MapTask: bufstart = 0; bufvoid = 104857600
14/10/07 03:36:03 INFO mapred.MapTask: kvstart = 26214396; length = 6553600
14/10/07 03:36:03 INFO mapred.LocalJobRunner: 
14/10/07 03:36:03 INFO mapred.MapTask: Starting flush of map output
14/10/07 03:36:03 INFO mapred.Task: Task:attempt_local1185570365_0001_m_000002_0 is done. And is in the process of committing
14/10/07 03:36:03 INFO mapred.LocalJobRunner: map
14/10/07 03:36:03 INFO mapred.Task: Task ‘attempt_local1185570365_0001_m_000002_0‘ done.
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_m_000002_0
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_m_000003_0
14/10/07 03:36:03 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:03 INFO mapred.MapTask: Processing split: file:/opt/hadoop-2.5.1/input/core-site.xml:0+774
14/10/07 03:36:03 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
14/10/07 03:36:03 INFO mapred.MapTask: (EQUATOR) 0 kvi 26214396(104857584)
14/10/07 03:36:03 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 100
14/10/07 03:36:03 INFO mapred.MapTask: soft limit at 83886080
14/10/07 03:36:03 INFO mapred.MapTask: bufstart = 0; bufvoid = 104857600
14/10/07 03:36:03 INFO mapred.MapTask: kvstart = 26214396; length = 6553600
14/10/07 03:36:03 INFO mapred.LocalJobRunner: 
14/10/07 03:36:03 INFO mapred.MapTask: Starting flush of map output
14/10/07 03:36:03 INFO mapred.Task: Task:attempt_local1185570365_0001_m_000003_0 is done. And is in the process of committing
14/10/07 03:36:03 INFO mapred.LocalJobRunner: map
14/10/07 03:36:03 INFO mapred.Task: Task ‘attempt_local1185570365_0001_m_000003_0‘ done.
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_m_000003_0
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_m_000004_0
14/10/07 03:36:03 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:03 INFO mapred.MapTask: Processing split: file:/opt/hadoop-2.5.1/input/yarn-site.xml:0+690
14/10/07 03:36:03 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
14/10/07 03:36:03 INFO mapred.MapTask: (EQUATOR) 0 kvi 26214396(104857584)
14/10/07 03:36:03 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 100
14/10/07 03:36:03 INFO mapred.MapTask: soft limit at 83886080
14/10/07 03:36:03 INFO mapred.MapTask: bufstart = 0; bufvoid = 104857600
14/10/07 03:36:03 INFO mapred.MapTask: kvstart = 26214396; length = 6553600
14/10/07 03:36:03 INFO mapred.LocalJobRunner: 
14/10/07 03:36:03 INFO mapred.MapTask: Starting flush of map output
14/10/07 03:36:03 INFO mapred.Task: Task:attempt_local1185570365_0001_m_000004_0 is done. And is in the process of committing
14/10/07 03:36:03 INFO mapred.LocalJobRunner: map
14/10/07 03:36:03 INFO mapred.Task: Task ‘attempt_local1185570365_0001_m_000004_0‘ done.
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_m_000004_0
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_m_000005_0
14/10/07 03:36:03 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:03 INFO mapred.MapTask: Processing split: file:/opt/hadoop-2.5.1/input/httpfs-site.xml:0+620
14/10/07 03:36:03 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
14/10/07 03:36:03 INFO mapred.MapTask: (EQUATOR) 0 kvi 26214396(104857584)
14/10/07 03:36:03 INFO mapred.MapTask: mapreduce.task.io.sort.mb: 100
14/10/07 03:36:03 INFO mapred.MapTask: soft limit at 83886080
14/10/07 03:36:03 INFO mapred.MapTask: bufstart = 0; bufvoid = 104857600
14/10/07 03:36:03 INFO mapred.MapTask: kvstart = 26214396; length = 6553600
14/10/07 03:36:03 INFO mapred.LocalJobRunner: 
14/10/07 03:36:03 INFO mapred.MapTask: Starting flush of map output
14/10/07 03:36:03 INFO mapred.Task: Task:attempt_local1185570365_0001_m_000005_0 is done. And is in the process of committing
14/10/07 03:36:03 INFO mapred.LocalJobRunner: map
14/10/07 03:36:03 INFO mapred.Task: Task ‘attempt_local1185570365_0001_m_000005_0‘ done.
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_m_000005_0
14/10/07 03:36:03 INFO mapred.LocalJobRunner: map task executor complete.
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Waiting for reduce tasks
14/10/07 03:36:03 INFO mapred.LocalJobRunner: Starting task: attempt_local1185570365_0001_r_000000_0
14/10/07 03:36:03 INFO mapred.Task:  Using ResourceCalculatorProcessTree : [ ]
14/10/07 03:36:03 INFO mapred.ReduceTask: Using ShuffleConsumerPlugin: org.apache.hadoop.mapreduce.task.reduce.Shuffle@57931be2
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: MergerManager: memoryLimit=363285696, maxSingleShuffleLimit=90821424, mergeThreshold=239768576, ioSortFactor=10, memToMemMergeOutputsThreshold=10
14/10/07 03:36:03 INFO reduce.EventFetcher: attempt_local1185570365_0001_r_000000_0 Thread started: EventFetcher for fetching Map Completion Events
14/10/07 03:36:03 INFO reduce.LocalFetcher: localfetcher#1 about to shuffle output of map attempt_local1185570365_0001_m_000001_0 decomp: 2 len: 6 to MEMORY
14/10/07 03:36:03 INFO reduce.InMemoryMapOutput: Read 2 bytes from map-output for attempt_local1185570365_0001_m_000001_0
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: closeInMemoryFile -> map-output of size: 2, inMemoryMapOutputs.size() -> 1, commitMemory -> 0, usedMemory ->2
14/10/07 03:36:03 INFO mapreduce.Job:  map 100% reduce 0%
14/10/07 03:36:03 INFO reduce.LocalFetcher: localfetcher#1 about to shuffle output of map attempt_local1185570365_0001_m_000004_0 decomp: 2 len: 6 to MEMORY
14/10/07 03:36:03 INFO reduce.InMemoryMapOutput: Read 2 bytes from map-output for attempt_local1185570365_0001_m_000004_0
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: closeInMemoryFile -> map-output of size: 2, inMemoryMapOutputs.size() -> 2, commitMemory -> 2, usedMemory ->4
14/10/07 03:36:03 INFO reduce.LocalFetcher: localfetcher#1 about to shuffle output of map attempt_local1185570365_0001_m_000005_0 decomp: 2 len: 6 to MEMORY
14/10/07 03:36:03 INFO reduce.InMemoryMapOutput: Read 2 bytes from map-output for attempt_local1185570365_0001_m_000005_0
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: closeInMemoryFile -> map-output of size: 2, inMemoryMapOutputs.size() -> 3, commitMemory -> 4, usedMemory ->6
14/10/07 03:36:03 INFO reduce.LocalFetcher: localfetcher#1 about to shuffle output of map attempt_local1185570365_0001_m_000002_0 decomp: 2 len: 6 to MEMORY
14/10/07 03:36:03 INFO reduce.InMemoryMapOutput: Read 2 bytes from map-output for attempt_local1185570365_0001_m_000002_0
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: closeInMemoryFile -> map-output of size: 2, inMemoryMapOutputs.size() -> 4, commitMemory -> 6, usedMemory ->8
14/10/07 03:36:03 INFO reduce.LocalFetcher: localfetcher#1 about to shuffle output of map attempt_local1185570365_0001_m_000003_0 decomp: 2 len: 6 to MEMORY
14/10/07 03:36:03 INFO reduce.InMemoryMapOutput: Read 2 bytes from map-output for attempt_local1185570365_0001_m_000003_0
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: closeInMemoryFile -> map-output of size: 2, inMemoryMapOutputs.size() -> 5, commitMemory -> 8, usedMemory ->10
14/10/07 03:36:03 INFO reduce.LocalFetcher: localfetcher#1 about to shuffle output of map attempt_local1185570365_0001_m_000000_0 decomp: 21 len: 25 to MEMORY
14/10/07 03:36:03 INFO reduce.InMemoryMapOutput: Read 21 bytes from map-output for attempt_local1185570365_0001_m_000000_0
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: closeInMemoryFile -> map-output of size: 21, inMemoryMapOutputs.size() -> 6, commitMemory -> 10, usedMemory ->31
14/10/07 03:36:03 INFO reduce.EventFetcher: EventFetcher is interrupted.. Returning
14/10/07 03:36:03 INFO mapred.LocalJobRunner: 6 / 6 copied.
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: finalMerge called with 6 in-memory map-outputs and 0 on-disk map-outputs
14/10/07 03:36:03 INFO mapred.Merger: Merging 6 sorted segments
14/10/07 03:36:03 INFO mapred.Merger: Down to the last merge-pass, with 1 segments left of total size: 10 bytes
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: Merged 6 segments, 31 bytes to disk to satisfy reduce memory limit
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: Merging 1 files, 25 bytes from disk
14/10/07 03:36:03 INFO reduce.MergeManagerImpl: Merging 0 segments, 0 bytes from memory into reduce
14/10/07 03:36:03 INFO mapred.Merger: Merging 1 sorted segments
14/10/07 03:36:03 INFO mapred.Merger: Down to the last merge-pass, with 1 segments left of total size: 10 bytes
14/10/07 03:36:03 INFO mapred.LocalJobRunner: 6 / 6 copied.
14/10/07 03:36:04 INFO Configuration.deprecation: mapred.skip.on is deprecated. Instead, use mapreduce.job.skiprecords
14/10/07 03:36:04 INFO mapred.Task: Task:attempt_local1185570365_0001_r_000000_0 is done. And is in the process of committing
14/10/07 03:36:04 INFO mapred.LocalJobRunner: 6 / 6 copied.
14/10/07 03:36:04 INFO mapred.Task: Task attempt_local1185570365_0001_r_000000_0 is allowed to commit now
14/10/07 03:36:04 INFO output.FileOutputCommitter: Saved output of task ‘attempt_local1185570365_0001_r_000000_0‘ to file:/opt/hadoop-2.5.1/grep-temp-767563685/_temporary/0/task_local1185570365_0001_r_000000
14/10/07 03:36:04 INFO mapred.LocalJobRunner: reduce > reduce
14/10/07 03:36:04 INFO mapred.Task: Task ‘attempt_local1185570365_0001_r_000000_0‘ done.
14/10/07 03:36:04 INFO mapred.LocalJobRunner: Finishing task: attempt_local1185570365_0001_r_000000_0
14/10/07 03:36:04 INFO mapred.LocalJobRunner: reduce task executor complete.
14/10/07 03:36:04 INFO mapreduce.Job:  map 100% reduce 100%
14/10/07 03:36:04 INFO mapreduce.Job: Job job_local1185570365_0001 completed successfully
14/10/07 03:36:04 INFO mapreduce.Job: Counters: 33
	File System Counters
		FILE: Number of bytes read=114663
		FILE: Number of bytes written=1613316
		FILE: Number of read operations=0
		FILE: Number of large read operations=0
		FILE: Number of write operations=0
	Map-Reduce Framework
		Map input records=405
		Map output records=1
		Map output bytes=17
		Map output materialized bytes=55
		Input split bytes=657
		Combine input records=1
		Combine output records=1
		Reduce input groups=1
		Reduce shuffle bytes=55
		Reduce input records=1
		Reduce output records=1
		Spilled Records=2
		Shuffled Maps =6
		Failed Shuffles=0
		Merged Map outputs=6
		GC time elapsed (ms)=225
		CPU time spent (ms)=0
		Physical memory (bytes) snapshot=0
		Virtual memory (bytes) snapshot=0
		Total committed heap usage (bytes)=1106100224
	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=15649
	File Output Format Counters 
		Bytes Written=123
14/10/07 03:36:04 INFO jvm.JvmMetrics: Cannot initialize JVM Metrics with processName=JobTracker, sessionId= - already initialized
org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory file:/opt/hadoop-2.5.1/output already exists
	at org.apache.hadoop.mapreduce.lib.output.FileOutputFormat.checkOutputSpecs(FileOutputFormat.java:146)
	at org.apache.hadoop.mapreduce.JobSubmitter.checkSpecs(JobSubmitter.java:458)
	at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:343)
	at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1285)
	at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1282)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
	at org.apache.hadoop.mapreduce.Job.submit(Job.java:1282)
	at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
	at org.apache.hadoop.examples.Grep.run(Grep.java:92)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at org.apache.hadoop.examples.Grep.main(Grep.java:101)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:72)
	at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:145)
	at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:74)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.hadoop.util.RunJar.main(RunJar.java:212)






Hadoop学习笔记（二）设置单节点集群


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