我是hadoop的新手，并试图在我的Windows 7机器上设置Hadoop 0.20.2的单节点。
我的问题是双重的 - 一个是关于安装本身的完整性，另一个是关于示例字数统计程序的reduce阶段中的错误。
我的安装步骤如下：
我正在关注安装程序http://blog.benhall.me.uk/2011/01/installing-hadoop-0210-on-windows.html。
我已经在我的localhost上安装了cygwin并设置了无密码的ssh 我的java版本是：
java version "1.7.0_02"
Java(TM) SE Runtime Environment (build 1.7.0_02-b13)
Java HotSpot(TM) 64-Bit Server VM (build 22.0-b10, mixed mode)
conf / core-site.xml的内容：
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>
conf / hdfs-site.xml的内容：
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
conf / mapred-site.xml的内容：
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>localhost:9001</value>
</property>
</configuration>
我设置了JAVA_HOME变量，命令“hadoop version”打印0.20.2 hadoop namenode -format创建没有任何错误的DFS
start-all.sh打印出namenode，secondarynamenode，datanode，jobtracker和tasktracker都已启动。
然而，命令“jps”打印：
$ jps
4584 Jps
11008 JobTracker
2084 NameNode
我注意到jps打印了tasktracker，secondarynamenode的pids。
我能够查看
的输出http://localhost:50030 for the jobtracker, http://localhost:50060 for the tasktracker and http://localhost:50070 for the namenode.
我尝试了put和get命令到hdfs并且它们都成功了：
bin/hadoop fs -mkdir In
bin/hadoop fs -put *.txt In
mkdir temp
bin/hadoop fs -get In temp
ls -l temp/In
$ ls -l temp/In/
total 365
348624 Mar 24 23:59 CHANGES.txt
13366 Mar 24 23:59 LICENSE.txt
101 Mar 24 23:59 NOTICE.txt
1366 Mar 24 23:59 README.txt
我也可以通过httpn接口浏览DFS来查看这些文件，用于namenode
我最初认为我的安装已经完成，并按http://jayant7k.blogspot.com/2010/06/writing-your-first-map-reduce-program.html
的方式运行了一个示例WordCount map-reduce程序我获得以下输出：
12/03/25 00:10:26 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
12/03/25 00:10:26 INFO input.FileInputFormat: Total input paths to process : 1
12/03/25 00:10:27 INFO mapred.JobClient: Running job: job_201203242348_0001
12/03/25 00:10:28 INFO mapred.JobClient: map 0% reduce 0%
12/03/25 00:10:35 INFO mapred.JobClient: map 100% reduce 0%
12/03/25 00:21:29 INFO mapred.JobClient: Task Id : attempt_201203242348_0001_r_0
00000_0, Status : FAILED
Shuffle Error: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out.
12/03/25 00:32:25 INFO mapred.JobClient: Task Id : attempt_201203242348_0001_r_0
00000_1, Status : FAILED
Shuffle Error: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out.
12/03/25 00:44:02 INFO mapred.JobClient: Task Id : attempt_201203242348_0001_r_0
00000_2, Status : FAILED
Shuffle Error: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out.
12/03/25 00:55:00 INFO mapred.JobClient: Job complete: job_201203242348_0001
12/03/25 00:55:00 INFO mapred.JobClient: Counters: 12
12/03/25 00:55:00 INFO mapred.JobClient: Job Counters
12/03/25 00:55:00 INFO mapred.JobClient: Launched reduce tasks=4
12/03/25 00:55:00 INFO mapred.JobClient: Launched map tasks=1
12/03/25 00:55:00 INFO mapred.JobClient: Data-local map tasks=1
12/03/25 00:55:00 INFO mapred.JobClient: Failed reduce tasks=1
12/03/25 00:55:00 INFO mapred.JobClient: FileSystemCounters
12/03/25 00:55:00 INFO mapred.JobClient: HDFS_BYTES_READ=13366
12/03/25 00:55:00 INFO mapred.JobClient: FILE_BYTES_WRITTEN=23511
12/03/25 00:55:00 INFO mapred.JobClient: Map-Reduce Framework
12/03/25 00:55:00 INFO mapred.JobClient: Combine output records=0
12/03/25 00:55:00 INFO mapred.JobClient: Map input records=244
12/03/25 00:55:00 INFO mapred.JobClient: Spilled Records=1887
12/03/25 00:55:00 INFO mapred.JobClient: Map output bytes=19699
12/03/25 00:55:00 INFO mapred.JobClient: Combine input records=0
12/03/25 00:55:00 INFO mapred.JobClient: Map output records=1887
map任务似乎已完成，但reduce任务在日志中显示以下错误：
2012-03-25 00:10:35,202 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0: Got 1 new map-outputs
2012-03-25 00:10:40,193 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Scheduled 1 outputs (0 slow hosts and0 dup hosts)
2012-03-25 00:10:40,243 INFO org.apache.hadoop.mapred.ReduceTask: header: attempt_201203242348_0001_m_000000_0, compressed len: 23479, decompressed len: 23475
2012-03-25 00:10:40,243 INFO org.apache.hadoop.mapred.ReduceTask: Shuffling 23475 bytes (23479 raw bytes) into RAM from attempt_201203242348_0001_m_000000_0
2012-03-25 00:11:35,194 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Need another 1 map output(s) where 1 is already in progress
2012-03-25 00:11:35,194 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Scheduled 0 outputs (0 slow hosts and0 dup hosts)
2012-03-25 00:12:35,197 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Need another 1 map output(s) where 1 is already in progress
2012-03-25 00:12:35,197 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Scheduled 0 outputs (0 slow hosts and0 dup hosts)
2012-03-25 00:13:35,202 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Need another 1 map output(s) where 1 is already in progress
2012-03-25 00:13:35,202 INFO org.apache.hadoop.mapred.ReduceTask: attempt_201203242348_0001_r_000000_0 Scheduled 0 outputs (0 slow hosts and0 dup hosts)
2012-03-25 00:13:40,249 INFO org.apache.hadoop.mapred.ReduceTask: Failed to shuffle from attempt_201203242348_0001_m_000000_0
java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:150)
at java.net.SocketInputStream.read(SocketInputStream.java:121)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:235)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:275)
at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
at sun.net.www.http.ChunkedInputStream.fastRead(ChunkedInputStream.java:239)
at sun.net.www.http.ChunkedInputStream.read(ChunkedInputStream.java:680)
at java.io.FilterInputStream.read(FilterInputStream.java:133)
at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:2959)
at org.apache.hadoop.mapred.IFileInputStream.doRead(IFileInputStream.java:149)
at org.apache.hadoop.mapred.IFileInputStream.read(IFileInputStream.java:101)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.shuffleInMemory(ReduceTask.java:1522)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getMapOutput(ReduceTask.java:1408)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.copyOutput(ReduceTask.java:1261)
at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.run(ReduceTask.java:1195)
以下是任务跟踪器日志的内容：
2012-03-25 00:10:27,910 INFO org.apache.hadoop.mapred.TaskTracker: LaunchTaskAction (registerTask): attempt_201203242348_0001_m_000002_0 task's state:UNASSIGNED
2012-03-25 00:10:27,915 INFO org.apache.hadoop.mapred.TaskTracker: Trying to launch : attempt_201203242348_0001_m_000002_0
2012-03-25 00:10:27,915 INFO org.apache.hadoop.mapred.TaskTracker: In TaskLauncher, current free slots : 2 and trying to launch attempt_201203242348_0001_m_000002_0
2012-03-25 00:10:28,453 INFO org.apache.hadoop.mapred.JvmManager: In JvmRunner constructed JVM ID: jvm_201203242348_0001_m_625085452
2012-03-25 00:10:28,454 INFO org.apache.hadoop.mapred.JvmManager: JVM Runner jvm_201203242348_0001_m_625085452 spawned.
2012-03-25 00:10:29,217 INFO org.apache.hadoop.mapred.TaskTracker: JVM with ID: jvm_201203242348_0001_m_625085452 given task: attempt_201203242348_0001_m_000002_0
2012-03-25 00:10:29,523 INFO org.apache.hadoop.mapred.TaskTracker: attempt_201203242348_0001_m_000002_0 0.0% setup
2012-03-25 00:10:29,524 INFO org.apache.hadoop.mapred.TaskTracker: Task attempt_201203242348_0001_m_000002_0 is done.
2012-03-25 00:10:29,524 INFO org.apache.hadoop.mapred.TaskTracker: reported output size for attempt_201203242348_0001_m_000002_0 was 0
2012-03-25 00:10:29,526 INFO org.apache.hadoop.mapred.TaskTracker: addFreeSlot : current free slots : 2
2012-03-25 00:10:29,718 INFO org.apache.hadoop.mapred.JvmManager: JVM : jvm_201203242348_0001_m_625085452 exited. Number of tasks it ran: 1
2012-03-25 00:10:30,911 INFO org.apache.hadoop.mapred.TaskTracker: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find taskTracker/jobcache/job_201203242348_0001/attempt_201203242348_0001_m_000002_0/output/file.out in any of the configured local directories
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.TaskTracker: LaunchTaskAction (registerTask): attempt_201203242348_0001_m_000000_0 task's state:UNASSIGNED
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.TaskTracker: Trying to launch : attempt_201203242348_0001_m_000000_0
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.TaskTracker: In TaskLauncher, current free slots : 2 and trying to launch attempt_201203242348_0001_m_000000_0
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.TaskTracker: Received KillTaskAction for task: attempt_201203242348_0001_m_000002_0
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.TaskTracker: About to purge task: attempt_201203242348_0001_m_000002_0
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.TaskRunner: attempt_201203242348_0001_m_000002_0 done; removing files.
2012-03-25 00:10:30,952 INFO org.apache.hadoop.mapred.IndexCache: Map ID attempt_201203242348_0001_m_000002_0 not found in cache
2012-03-25 00:10:31,077 INFO org.apache.hadoop.mapred.JvmManager: In JvmRunner constructed JVM ID: jvm_201203242348_0001_m_-1399302881
2012-03-25 00:10:31,077 INFO org.apache.hadoop.mapred.JvmManager: JVM Runner jvm_201203242348_0001_m_-1399302881 spawned.
2012-03-25 00:10:31,812 INFO org.apache.hadoop.mapred.TaskTracker: JVM with ID: jvm_201203242348_0001_m_-1399302881 given task: attempt_201203242348_0001_m_000000_0
2012-03-25 00:10:32,642 INFO org.apache.hadoop.mapred.TaskTracker: attempt_201203242348_0001_m_000000_0 1.0%
2012-03-25 00:10:32,642 INFO org.apache.hadoop.mapred.TaskTracker: Task attempt_201203242348_0001_m_000000_0 is done.
2012-03-25 00:10:32,642 INFO org.apache.hadoop.mapred.TaskTracker: reported output size for attempt_201203242348_0001_m_000000_0 was 0
2012-03-25 00:10:32,642 INFO org.apache.hadoop.mapred.TaskTracker: addFreeSlot : current free slots : 2
2012-03-25 00:10:32,822 INFO org.apache.hadoop.mapred.JvmManager: JVM : jvm_201203242348_0001_m_-1399302881 exited. Number of tasks it ran: 1
2012-03-25 00:10:33,982 INFO org.apache.hadoop.mapred.TaskTracker: LaunchTaskAction (registerTask): attempt_201203242348_0001_r_000000_0 task's state:UNASSIGNED
2012-03-25 00:10:33,982 INFO org.apache.hadoop.mapred.TaskTracker: Trying to launch : attempt_201203242348_0001_r_000000_0
2012-03-25 00:10:33,982 INFO org.apache.hadoop.mapred.TaskTracker: In TaskLauncher, current free slots : 2 and trying to launch attempt_201203242348_0001_r_000000_0
2012-03-25 00:10:34,057 INFO org.apache.hadoop.mapred.JvmManager: In JvmRunner constructed JVM ID: jvm_201203242348_0001_r_625085452
2012-03-25 00:10:34,057 INFO org.apache.hadoop.mapred.JvmManager: JVM Runner jvm_201203242348_0001_r_625085452 spawned.
2012-03-25 00:10:34,852 INFO org.apache.hadoop.mapred.TaskTracker: JVM with ID: jvm_201203242348_0001_r_625085452 given task: attempt_201203242348_0001_r_000000_0
2012-03-25 00:10:40,243 INFO org.apache.hadoop.mapred.TaskTracker: Sent out 23479 bytes for reduce: 0 from map: attempt_201203242348_0001_m_000000_0 given 23479/23475
2012-03-25 00:10:40,243 INFO org.apache.hadoop.mapred.TaskTracker.clienttrace: src: 192.168.1.33:50060, dest: 192.168.1.33:60790, bytes: 23479, op: MAPRED_SHUFFLE, cliID: attempt_201203242348_0001_m_000000_0
2012-03-25 00:10:41,153 INFO org.apache.hadoop.mapred.TaskTracker: attempt_201203242348_0001_r_000000_0 0.0% reduce > copy >
2012-03-25 00:10:44,158 INFO org.apache.hadoop.mapred.TaskTracker: attempt_201203242348_0001_r_000000_0 0.0% reduce > copy >
2012-03-25 00:16:05,244 INFO org.apache.hadoop.mapred.TaskTracker: Sent out 23479 bytes for reduce: 0 from map: attempt_201203242348_0001_m_000000_0 given 23479/23475
2012-03-25 00:16:05,244 INFO org.apache.hadoop.mapred.TaskTracker.clienttrace: src: 192.168.1.33:50060, dest: 192.168.1.33:60864, bytes: 23479, op: MAPRED_SHUFFLE, cliID: attempt_201203242348_0001_m_000000_0
2012-03-25 00:16:05,249 INFO org.apache.hadoop.mapred.TaskTracker: attempt_201203242348_0001_r_000000_0 0.0% reduce > copy >
2012-03-25 00:16:08,249 INFO org.apache.hadoop.mapred.TaskTracker: attempt_201203242348_0001_r_000000_0 0.0% reduce > copy >
2012-03-25 00:21:25,251 FATAL org.apache.hadoop.mapred.TaskTracker: Task: attempt_201203242348_0001_r_000000_0 - Killed due to Shuffle Failure: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out.
我在Windows防火墙中打开了端口9000和9001 我检查了telnet输出以验证这些端口是否确实打开了：
C:\Windows\system32>netstat -a -n | grep -e "500[367]0"
TCP 0.0.0.0:50030 0.0.0.0:0 LISTENING
TCP 0.0.0.0:50060 0.0.0.0:0 LISTENING
TCP 0.0.0.0:50070 0.0.0.0:0 LISTENING
TCP [::]:50030 [::]:0 LISTENING
TCP [::]:50060 [::]:0 LISTENING
TCP [::]:50070 [::]:0 LISTENING
C:\Windows\system32>netstat -a -n | grep -e "900[01]"
TCP 127.0.0.1:9000 0.0.0.0:0 LISTENING
TCP 127.0.0.1:9000 127.0.0.1:60332 ESTABLISHED
TCP 127.0.0.1:9000 127.0.0.1:60987 ESTABLISHED
TCP 127.0.0.1:9001 0.0.0.0:0 LISTENING
TCP 127.0.0.1:9001 127.0.0.1:60410 ESTABLISHED
TCP 127.0.0.1:60332 127.0.0.1:9000 ESTABLISHED
TCP 127.0.0.1:60410 127.0.0.1:9001 ESTABLISHED
TCP 127.0.0.1:60987 127.0.0.1:9000 ESTABLISHED
您可以帮助解决安装问题并使reduce任务正常工作吗？
我查看了
http://wiki.apache.org/hadoop/SocketTimeout和其他一些链接并尝试了这些建议，但没有取得任何成功。
感谢您耐心阅读本文，并很乐意提供其他详细信息。
提前致谢。
答案 0 :(得分：1)
在日志中查看此行：
2012-03-25 00:10:30,911 INFO org.apache.hadoop.mapred.TaskTracker: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find taskTracker/jobcache/job_201203242348_0001/attempt_201203242348_0001_m_000002_0/output/file.out in any of the configured local directories
我猜你需要检查hadoop.tmp.dir和mapred.local.dir。您提到了您正在使用的配置，因此这两个参数的值是默认值。这些参数的默认值为here。将它们设置到某个相关位置，然后重试。
注意：在您进行此更改之前，您需要停止hadoop并在完成后启动。