java – Hadoop map-reduce操作在写入输出时失败
作者：互联网
我终于能够在Hadoop上启动map-reduce工作(在单个debian机器上运行).但是,map reduce作业始终失败,并显示以下错误：
hadoopmachine@debian:~$./hadoop-1.0.1/bin/hadoop jar hadooptest/main.jar nl.mydomain.hadoop.debian.test.Main /user/hadoopmachine/input /user/hadoopmachine/output
Warning: $HADOOP_HOME is deprecated.
12/04/03 07:29:35 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
****hdfs://localhost:9000/user/hadoopmachine/input
12/04/03 07:29:35 INFO input.FileInputFormat: Total input paths to process : 1
12/04/03 07:29:35 INFO mapred.JobClient: Running job: job_201204030722_0002
12/04/03 07:29:36 INFO mapred.JobClient: map 0% reduce 0%
12/04/03 07:29:41 INFO mapred.JobClient: Task Id : attempt_201204030722_0002_m_000002_0, Status : FAILED
Error initializing attempt_201204030722_0002_m_000002_0:
ENOENT: No such file or directory
at org.apache.hadoop.io.nativeio.NativeIO.chmod(Native Method)
at org.apache.hadoop.fs.FileUtil.execSetPermission(FileUtil.java:692)
at org.apache.hadoop.fs.FileUtil.setPermission(FileUtil.java:647)
at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:509)
at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:344)
at org.apache.hadoop.mapred.JobLocalizer.initializeJobLogDir(JobLocalizer.java:239)
at org.apache.hadoop.mapred.DefaultTaskController.initializeJob(DefaultTaskController.java:196)
at org.apache.hadoop.mapred.TaskTracker$4.run(TaskTracker.java:1226)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:416)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1093)
at org.apache.hadoop.mapred.TaskTracker.initializeJob(TaskTracker.java:1201)
at org.apache.hadoop.mapred.TaskTracker.localizeJob(TaskTracker.java:1116)
at org.apache.hadoop.mapred.TaskTracker$5.run(TaskTracker.java:2404)
at java.lang.Thread.run(Thread.java:636)
12/04/03 07:29:41 WARN mapred.JobClient: Error reading task outputhttp://localhost:50060/tasklog?plaintext=true&attemptid=attempt_201204030722_0002_m_000002_0&filter=stdout
12/04/03 07:29:41 WARN mapred.JobClient: Error reading task outputhttp://localhost:50060/tasklog?plaintext=true&attemptid=attempt_201204030722_0002_m_000002_0&filter=stderr
不幸的是,它只说：“ENOENT：没有这样的文件或目录”,它没有说明它实际尝试访问的目录. Ping localhost工作,输入目录确实存在.罐子的位置也是正确的.
任何人都可以给我一个指针,指出如何解决这个错误,或者如何找出Hadoop试图访问哪个文件？
我在Hadoop邮件列表上发现了几个类似的问题,但没有对这些问题做出回应……
谢谢！
附： mapred.local.dir的配置如下所示(在mapred-site.xml中)：
<property>
<name>mapred.local.dir</name>
<value>/home/hadoopmachine/hadoop_data/mapred</value>
<final>true</final>
</property>
根据要求,ps auxww |的输出grep TaskTracker是：
1000 4249 2.2 0.8 1181992 30176 ? Sl 12:09 0:00
/usr/lib/jvm/java-6-openjdk/bin/java -Dproc_tasktracker -Xmx1000m -Dhadoop.log.dir=/home/hadoopmachine/hadoop-1.0.1/libexec/../logs
-Dhadoop.log.file=hadoop-hadoopmachine-tasktracker-debian.log -Dhadoop.home.dir=/home/hadoopmachine/hadoop-1.0.1/libexec/..
-Dhadoop.id.str=hadoopmachine -Dhadoop.root.logger=INFO,DRFA -Dhadoop.security.logger=INFO,NullAppender
-Djava.library.path=/home/hadoopmachine/hadoop-1.0.1/libexec/../lib/native/Linux-i386-32
-Dhadoop.policy.file=hadoop-policy.xml -classpath [ommitted very long list of jars] org.apache.hadoop.mapred.TaskTracker
解决方法:
从作业跟踪器中,确定执行此任务的hadoop节点. SSH到该节点并识别hadoop.log.dir目录的位置(检查此节点的mapred-site.xml) – 我的猜测是hadoop用户没有在此文件夹中创建子目录的正确权限
它尝试创建的实际文件夹位于${hadoop.log.dir} / userlogs文件夹下 – 检查此文件夹是否具有正确的权限
在你的情况下,看看ps输出,我猜这是你需要检查权限的文件夹：
/home/hadoopmachine/hadoop-1.0.1/libexec/../logs
标签：java,debian,hadoop,mapreduce,file-access 来源： https://codeday.me/bug/20190626/1291210.html