2014-12-16 15:31:46,213 WARN [main] security.UserGroupInformation (UserGroupInformation.java:doAs(1551)) - PriviledgedActionException as:hadoop (auth:SIMPLE) cause:org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://192.168.52.128:9000/data/output already exists
Exception in thread "main" org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://192.168.52.128:9000/data/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)
删除原来的/data/output目录
12，运行报错(10)：
Could not locate executable null\bin\winutils.exe in the Hadoop binaries
老掉牙的问题了，系统变量未设置HADOOP_HOME，系统变量设置HADOOP_HOME，或者直接加一句代码指定路径地址：
System.setProperty("hadoop.home.dir", "E:/hadoop/hadoop-2.3.0");
13，运行报错(11)：
2014-12-16 14:28:58,589 WARN [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2014-12-16 14:29:08,664 INFO [main] Configuration.deprecation (Configuration.java:warnOnceIfDeprecated(996)) - session.id is deprecated. Instead, use dfs.metrics.session-id
2014-12-16 14:29:08,665 INFO [main] jvm.JvmMetrics (JvmMetrics.java:init(76)) - Initializing JVM Metrics with processName=JobTracker, sessionId=
2014-12-16 14:29:10,026 INFO [main] input.FileInputFormat (FileInputFormat.java:listStatus(287)) - Total input paths to process : 1
2014-12-16 14:29:11,164 INFO [main] mapreduce.JobSubmitter (JobSubmitter.java:submitJobInternal(396)) - number of splits:1
2014-12-16 14:29:11,761 INFO [main] mapreduce.JobSubmitter (JobSubmitter.java:printTokens(479)) - Submitting tokens for job: job_local1985238633_0001
2014-12-16 14:29:11,810 WARN [main] conf.Configuration (Configuration.java:loadProperty(2345)) - file:/tmp/hadoop-hadoop/mapred/staging/hadoop1985238633/.staging/job_local1985238633_0001/job.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval; Ignoring.
2014-12-16 14:29:11,811 WARN [main] conf.Configuration (Configuration.java:loadProperty(2345)) - file:/tmp/hadoop-hadoop/mapred/staging/hadoop1985238633/.staging/job_local1985238633_0001/job.xml:an attempt to override final parameter: mapreduce.job.end-notification.max.attempts; Ignoring.
2014-12-16 14:29:11,916 INFO [main] mapreduce.JobSubmitter (JobSubmitter.java:submitJobInternal(441)) - Cleaning up the staging area file:/tmp/hadoop-hadoop/mapred/staging/hadoop1985238633/.staging/job_local1985238633_0001
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$Windows.access(NativeIO.java:560)
at org.apache.hadoop.fs.FileUtil.canRead(FileUtil.java:977)
at org.apache.hadoop.util.DiskChecker.checkAccessByFileMethods(DiskChecker.java:177)
at org.apache.hadoop.util.DiskChecker.checkDirAccess(DiskChecker.java:164)
at org.apache.hadoop.util.DiskChecker.checkDir(DiskChecker.java:98)
at org.apache.hadoop.fs.LocalDirAllocator$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:432)
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(Unknown Source)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1548)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1282)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
at wc.W2.main(W2.java:111)