hadoop执行mapreduce任务，能够map，不能reduce，Shuffle阶段报错

第一次运行：
[root@sjfx jar]# hadoop jar /home/tangzw/jar/GameLoginLogAnalyzeA.jar /tangzw/input /tangzw/output 08/01/25 07:13:43 INFO client.RMProxy: Connecting to ResourceManager at sjfx/192.168.57.127:18040 08/01/25 07:13:43 INFO client.RMProxy: Connecting to ResourceManager at sjfx/192.168.57.127:18040 08/01/25 07:13:43 WARN mapreduce.JobSubmitter: Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this. 08/01/25 07:13:44 INFO mapred.FileInputFormat: Total input paths to process : 13 08/01/25 07:13:44 INFO mapreduce.JobSubmitter: number of splits:103 08/01/25 07:13:44 INFO Configuration.deprecation: user.name is deprecated. Instead, use mapreduce.job.user.name 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.output.value.class is deprecated. Instead, use mapreduce.job.output.value.class 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.job.name is deprecated. Instead, use mapreduce.job.name 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.input.dir is deprecated. Instead, use mapreduce.input.fileinputformat.inputdir 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.output.dir is deprecated. Instead, use mapreduce.output.fileoutputformat.outputdir 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.output.key.class is deprecated. Instead, use mapreduce.job.output.key.class 08/01/25 07:13:44 INFO Configuration.deprecation: mapred.working.dir is deprecated. Instead, use mapreduce.job.working.dir 08/01/25 07:13:45 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1201209004442_0001 08/01/25 07:13:46 INFO impl.YarnClientImpl: Submitted application application_1201209004442_0001 to ResourceManager at sjfx/192.168.57.127:18040 08/01/25 07:13:46 INFO mapreduce.Job: The url to track the job: http://sjfx:18088/proxy/application_1201209004442_0001/ 08/01/25 07:13:46 INFO mapreduce.Job: Running job: job_1201209004442_0001 08/01/25 07:13:57 INFO mapreduce.Job: Job job_1201209004442_0001 running in uber mode : false 08/01/25 07:13:57 INFO mapreduce.Job:  map 0% reduce 0% 08/01/25 07:14:36 INFO mapreduce.Job:  map 2% reduce 0% 08/01/25 07:14:46 INFO mapreduce.Job:  map 3% reduce 0% 08/01/25 07:14:51 INFO mapreduce.Job:  map 4% reduce 0% 08/01/25 07:14:54 INFO mapreduce.Job:  map 5% reduce 0% 08/01/25 07:14:57 INFO mapreduce.Job:  map 6% reduce 0% 08/01/25 07:15:04 INFO mapreduce.Job:  map 7% reduce 0% 08/01/25 07:15:16 INFO mapreduce.Job:  map 8% reduce 0% 08/01/25 07:15:22 INFO mapreduce.Job:  map 9% reduce 0% 08/01/25 07:17:01 INFO mapreduce.Job:  map 10% reduce 0% 08/01/25 07:17:56 INFO mapreduce.Job:  map 11% reduce 0% 08/01/25 07:18:38 INFO mapreduce.Job:  map 12% reduce 0% 08/01/25 07:19:11 INFO mapreduce.Job:  map 13% reduce 0% 08/01/25 07:19:20 INFO mapreduce.Job:  map 14% reduce 0% 08/01/25 07:19:34 INFO mapreduce.Job:  map 15% reduce 0% 08/01/25 07:20:37 INFO mapreduce.Job:  map 16% reduce 0% 08/01/25 07:20:52 INFO mapreduce.Job:  map 17% reduce 0% 08/01/25 07:21:39 INFO mapreduce.Job:  map 18% reduce 0% 08/01/25 07:22:06 INFO mapreduce.Job:  map 19% reduce 0% 08/01/25 07:23:18 INFO mapreduce.Job:  map 20% reduce 0% 08/01/25 07:23:38 INFO mapreduce.Job:  map 21% reduce 0% 08/01/25 07:24:24 INFO mapreduce.Job:  map 24% reduce 0% 08/01/25 07:24:30 INFO mapreduce.Job:  map 25% reduce 0% 08/01/25 07:25:07 INFO mapreduce.Job:  map 26% reduce 0% 08/01/25 07:25:35 INFO mapreduce.Job:  map 27% reduce 0% 08/01/25 07:26:10 INFO mapreduce.Job:  map 28% reduce 0% 08/01/25 07:26:19 INFO mapreduce.Job:  map 29% reduce 0% 08/01/25 07:26:35 INFO mapreduce.Job:  map 29% reduce 1% 08/01/25 07:27:13 INFO mapreduce.Job:  map 30% reduce 1% 08/01/25 07:27:24 INFO mapreduce.Job:  map 31% reduce 1% 08/01/25 07:28:42 INFO mapreduce.Job:  map 32% reduce 1% 08/01/25 07:28:50 INFO mapreduce.Job:  map 33% reduce 1% 08/01/25 07:28:56 INFO mapreduce.Job:  map 34% reduce 1% 08/01/25 07:29:02 INFO mapreduce.Job:  map 35% reduce 1% 08/01/25 07:29:05 INFO mapreduce.Job:  map 36% reduce 1% 08/01/25 07:30:03 INFO mapreduce.Job:  map 37% reduce 1% 08/01/25 07:30:31 INFO mapreduce.Job:  map 38% reduce 1% 08/01/25 07:30:56 INFO mapreduce.Job:  map 39% reduce 1% 08/01/25 07:32:16 INFO mapreduce.Job:  map 40% reduce 1% 08/01/25 07:33:15 INFO mapreduce.Job:  map 41% reduce 1% 08/01/25 07:33:27 INFO mapreduce.Job:  map 42% reduce 1% 08/01/25 07:33:31 INFO mapreduce.Job:  map 43% reduce 1% 08/01/25 07:33:36 INFO mapreduce.Job:  map 44% reduce 1% 08/01/25 07:33:40 INFO mapreduce.Job:  map 45% reduce 1% 08/01/25 07:34:26 INFO mapreduce.Job:  map 46% reduce 1% 08/01/25 07:35:30 INFO mapreduce.Job:  map 46% reduce 2% 08/01/25 07:35:43 INFO mapreduce.Job:  map 47% reduce 2% 08/01/25 07:35:50 INFO mapreduce.Job:  map 48% reduce 2% 08/01/25 07:36:04 INFO mapreduce.Job:  map 49% reduce 2% 08/01/25 07:37:31 INFO mapreduce.Job:  map 50% reduce 2% 08/01/25 07:38:33 INFO mapreduce.Job:  map 51% reduce 2% 08/01/25 07:39:26 INFO mapreduce.Job:  map 52% reduce 2% 08/01/25 07:39:29 INFO mapreduce.Job:  map 53% reduce 2% 08/01/25 07:39:35 INFO mapreduce.Job:  map 54% reduce 2% 08/01/25 07:39:38 INFO mapreduce.Job:  map 55% reduce 2% 08/01/25 07:40:25 INFO mapreduce.Job:  map 56% reduce 2% 08/01/25 07:40:58 INFO mapreduce.Job:  map 56% reduce 3% 08/01/25 07:41:25 INFO mapreduce.Job:  map 57% reduce 3% 08/01/25 07:42:17 INFO mapreduce.Job:  map 58% reduce 3% 08/01/25 07:43:12 INFO mapreduce.Job:  map 59% reduce 3% 08/01/25 07:43:18 INFO mapreduce.Job:  map 60% reduce 3% 08/01/25 07:43:42 INFO mapreduce.Job:  map 61% reduce 3% 08/01/25 07:44:19 INFO mapreduce.Job:  map 62% reduce 3% 08/01/25 07:45:12 INFO mapreduce.Job:  map 63% reduce 3% 08/01/25 07:46:01 INFO mapreduce.Job:  map 64% reduce 3% 08/01/25 07:46:33 INFO mapreduce.Job:  map 64% reduce 4% 08/01/25 07:46:36 INFO mapreduce.Job:  map 65% reduce 4% 08/01/25 07:47:02 INFO mapreduce.Job:  map 66% reduce 4% 08/01/25 07:47:08 INFO mapreduce.Job:  map 67% reduce 4% 08/01/25 07:47:30 INFO mapreduce.Job:  map 68% reduce 4% 08/01/25 07:47:36 INFO mapreduce.Job:  map 69% reduce 4% 08/01/25 07:47:42 INFO mapreduce.Job:  map 70% reduce 4% 08/01/25 07:47:51 INFO mapreduce.Job:  map 71% reduce 4% 08/01/25 07:48:13 INFO mapreduce.Job:  map 72% reduce 4% 08/01/25 07:48:19 INFO mapreduce.Job:  map 73% reduce 4% 08/01/25 07:48:40 INFO mapreduce.Job:  map 74% reduce 4% 08/01/25 07:48:53 INFO mapreduce.Job:  map 75% reduce 4% 08/01/25 07:49:15 INFO mapreduce.Job:  map 76% reduce 4% 08/01/25 07:49:55 INFO mapreduce.Job:  map 77% reduce 4% 08/01/25 07:51:06 INFO mapreduce.Job:  map 78% reduce 4% 08/01/25 07:51:48 INFO mapreduce.Job:  map 78% reduce 5% 08/01/25 07:51:54 INFO mapreduce.Job:  map 79% reduce 5% 08/01/25 07:52:06 INFO mapreduce.Job:  map 80% reduce 5% 08/01/25 07:52:10 INFO mapreduce.Job:  map 81% reduce 5% 08/01/25 07:52:19 INFO mapreduce.Job:  map 82% reduce 5% 08/01/25 07:52:25 INFO mapreduce.Job:  map 83% reduce 5% 08/01/25 07:53:10 INFO mapreduce.Job:  map 84% reduce 5% 08/01/25 07:54:10 INFO mapreduce.Job:  map 85% reduce 6% 08/01/25 07:54:27 INFO mapreduce.Job:  map 86% reduce 6% 08/01/25 07:54:31 INFO mapreduce.Job:  map 87% reduce 6% 08/01/25 07:54:34 INFO mapreduce.Job:  map 88% reduce 6% 08/01/25 07:54:37 INFO mapreduce.Job:  map 89% reduce 6% 08/01/25 07:54:48 INFO mapreduce.Job:  map 90% reduce 6% 08/01/25 07:55:17 INFO mapreduce.Job:  map 91% reduce 6% 08/01/25 07:55:33 INFO mapreduce.Job:  map 93% reduce 6% 08/01/25 07:55:36 INFO mapreduce.Job:  map 94% reduce 6% 08/01/25 07:55:40 INFO mapreduce.Job:  map 95% reduce 6% 08/01/25 07:55:49 INFO mapreduce.Job:  map 96% reduce 6% 08/01/25 07:55:56 INFO mapreduce.Job:  map 97% reduce 6% 08/01/25 07:57:25 INFO mapreduce.Job:  map 98% reduce 6% 08/01/25 07:57:28 INFO mapreduce.Job:  map 99% reduce 6% 08/01/25 07:57:45 INFO mapreduce.Job:  map 100% reduce 6% 08/01/25 07:58:50 INFO mapreduce.Job:  map 100% reduce 7% 08/01/25 08:00:01 INFO mapreduce.Job:  map 100% reduce 8% 08/01/25 08:01:10 INFO mapreduce.Job:  map 100% reduce 9% 08/01/25 08:02:44 INFO mapreduce.Job:  map 100% reduce 10% 08/01/25 08:03:45 INFO mapreduce.Job:  map 100% reduce 11% 08/01/25 08:04:07 INFO mapreduce.Job: Task Id : attempt_1201209004442_0001_r_000000_0, Status : FAILED Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#1 at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:121) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:380) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for output/attempt_1201209004442_0001_r_000000_0/map_41.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getInputFileForWrite(YarnOutputFiles.java:213) at org.apache.hadoop.mapreduce.task.reduce.OnDiskMapOutput.<init>(OnDiskMapOutput.java:61) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:257) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:411) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:341) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:165)
08/01/25 08:04:08 INFO mapreduce.Job:  map 100% reduce 0% 08/01/25 08:05:01 INFO mapreduce.Job: Task Id : attempt_1201209004442_0001_r_000000_1, Status : FAILED Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#5 at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:121) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:380) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for output/attempt_1201209004442_0001_r_000000_1/map_11.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getInputFileForWrite(YarnOutputFiles.java:213) at org.apache.hadoop.mapreduce.task.reduce.OnDiskMapOutput.<init>(OnDiskMapOutput.java:61) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:257) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:411) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:341) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:165)
08/01/25 08:05:17 INFO mapreduce.Job:  map 100% reduce 1% 08/01/25 08:05:42 INFO mapreduce.Job:  map 100% reduce 2% 08/01/25 08:05:58 INFO mapreduce.Job:  map 100% reduce 3% 08/01/25 08:06:26 INFO mapreduce.Job:  map 100% reduce 4% 08/01/25 08:07:15 INFO mapreduce.Job:  map 100% reduce 5% 08/01/25 08:07:48 INFO mapreduce.Job:  map 100% reduce 6% 08/01/25 08:08:21 INFO mapreduce.Job: Task Id : attempt_1201209004442_0001_r_000000_2, Status : FAILED Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#4 at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:121) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:380) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for output/attempt_1201209004442_0001_r_000000_2/map_20.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getInputFileForWrite(YarnOutputFiles.java:213) at org.apache.hadoop.mapreduce.task.reduce.OnDiskMapOutput.<init>(OnDiskMapOutput.java:61) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:257) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:411) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:341) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:165)
08/01/25 08:08:22 INFO mapreduce.Job:  map 100% reduce 0%

第二次运行：


[root@sjfx jar]# hadoop jar GameLoginLogAnalyzeA.jar /tangzw/input /tangzw/output 14/10/04 11:30:36 INFO client.RMProxy: Connecting to ResourceManager at sjfx/192.168.57.127:18040 14/10/04 11:30:36 INFO client.RMProxy: Connecting to ResourceManager at sjfx/192.168.57.127:18040 14/10/04 11:30:37 WARN mapreduce.JobSubmitter: Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this. 14/10/04 11:30:38 INFO mapred.FileInputFormat: Total input paths to process : 13 14/10/04 11:30:38 INFO mapreduce.JobSubmitter: number of splits:103 14/10/04 11:30:38 INFO Configuration.deprecation: user.name is deprecated. Instead, use mapreduce.job.user.name 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.output.value.class is deprecated. Instead, use mapreduce.job.output.value.class 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.job.name is deprecated. Instead, use mapreduce.job.name 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.input.dir is deprecated. Instead, use mapreduce.input.fileinputformat.inputdir 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.output.dir is deprecated. Instead, use mapreduce.output.fileoutputformat.outputdir 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.output.key.class is deprecated. Instead, use mapreduce.job.output.key.class 14/10/04 11:30:38 INFO Configuration.deprecation: mapred.working.dir is deprecated. Instead, use mapreduce.job.working.dir 14/10/04 11:30:39 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1412391426441_0002 14/10/04 11:30:39 INFO impl.YarnClientImpl: Submitted application application_1412391426441_0002 to ResourceManager at sjfx/192.168.57.127:18040 14/10/04 11:30:39 INFO mapreduce.Job: The url to track the job: http://sjfx:18088/proxy/application_1412391426441_0002/ 14/10/04 11:30:39 INFO mapreduce.Job: Running job: job_1412391426441_0002 14/10/04 11:30:48 INFO mapreduce.Job: Job job_1412391426441_0002 running in uber mode : false 14/10/04 11:30:48 INFO mapreduce.Job:  map 0% reduce 0% 14/10/04 11:31:27 INFO mapreduce.Job:  map 1% reduce 0% 14/10/04 11:31:31 INFO mapreduce.Job:  map 4% reduce 0% 14/10/04 11:31:46 INFO mapreduce.Job:  map 5% reduce 0% 14/10/04 11:31:51 INFO mapreduce.Job:  map 7% reduce 0% 14/10/04 11:32:08 INFO mapreduce.Job:  map 9% reduce 0% 14/10/04 11:32:11 INFO mapreduce.Job:  map 10% reduce 0% 14/10/04 11:32:35 INFO mapreduce.Job:  map 11% reduce 0% 14/10/04 11:33:16 INFO mapreduce.Job:  map 12% reduce 0% 14/10/04 11:33:19 INFO mapreduce.Job:  map 13% reduce 0% 14/10/04 11:33:31 INFO mapreduce.Job:  map 14% reduce 0% 14/10/04 11:33:35 INFO mapreduce.Job:  map 15% reduce 0% 14/10/04 11:33:42 INFO mapreduce.Job:  map 16% reduce 0% 14/10/04 11:34:00 INFO mapreduce.Job:  map 17% reduce 0% 14/10/04 11:34:25 INFO mapreduce.Job:  map 18% reduce 0% 14/10/04 11:34:38 INFO mapreduce.Job:  map 19% reduce 0% 14/10/04 11:35:05 INFO mapreduce.Job:  map 20% reduce 0% 14/10/04 11:35:16 INFO mapreduce.Job:  map 21% reduce 0% 14/10/04 11:35:21 INFO mapreduce.Job:  map 22% reduce 0% 14/10/04 11:35:32 INFO mapreduce.Job:  map 23% reduce 0% 14/10/04 11:36:04 INFO mapreduce.Job:  map 24% reduce 0% 14/10/04 11:36:23 INFO mapreduce.Job:  map 24% reduce 1% 14/10/04 11:36:48 INFO mapreduce.Job:  map 25% reduce 1% 14/10/04 11:36:51 INFO mapreduce.Job:  map 26% reduce 1% 14/10/04 11:36:54 INFO mapreduce.Job:  map 27% reduce 1% 14/10/04 11:36:57 INFO mapreduce.Job:  map 28% reduce 1% 14/10/04 11:37:06 INFO mapreduce.Job:  map 29% reduce 1% 14/10/04 11:37:22 INFO mapreduce.Job:  map 31% reduce 1% 14/10/04 11:37:32 INFO mapreduce.Job:  map 32% reduce 1% 14/10/04 11:37:43 INFO mapreduce.Job:  map 33% reduce 2% 14/10/04 11:38:05 INFO mapreduce.Job:  map 34% reduce 2% 14/10/04 11:38:27 INFO mapreduce.Job:  map 35% reduce 2% 14/10/04 11:38:53 INFO mapreduce.Job:  map 36% reduce 2% 14/10/04 11:39:02 INFO mapreduce.Job:  map 37% reduce 2% 14/10/04 11:39:08 INFO mapreduce.Job:  map 38% reduce 2% 14/10/04 11:39:34 INFO mapreduce.Job:  map 39% reduce 2% 14/10/04 11:39:40 INFO mapreduce.Job:  map 39% reduce 3% 14/10/04 11:39:46 INFO mapreduce.Job:  map 40% reduce 3% 14/10/04 11:39:49 INFO mapreduce.Job:  map 41% reduce 3% 14/10/04 11:40:19 INFO mapreduce.Job:  map 43% reduce 3% 14/10/04 11:40:49 INFO mapreduce.Job:  map 44% reduce 3% 14/10/04 11:41:11 INFO mapreduce.Job:  map 45% reduce 3% 14/10/04 11:41:13 INFO mapreduce.Job:  map 45% reduce 4% 14/10/04 11:41:33 INFO mapreduce.Job:  map 46% reduce 4% 14/10/04 11:41:44 INFO mapreduce.Job:  map 47% reduce 4% 14/10/04 11:41:50 INFO mapreduce.Job:  map 48% reduce 4% 14/10/04 11:41:58 INFO mapreduce.Job:  map 49% reduce 4% 14/10/04 11:42:14 INFO mapreduce.Job:  map 50% reduce 4% 14/10/04 11:42:27 INFO mapreduce.Job:  map 51% reduce 4% 14/10/04 11:42:40 INFO mapreduce.Job:  map 52% reduce 4% 14/10/04 11:43:02 INFO mapreduce.Job:  map 53% reduce 4% 14/10/04 11:43:17 INFO mapreduce.Job:  map 54% reduce 4% 14/10/04 11:43:41 INFO mapreduce.Job:  map 55% reduce 4% 14/10/04 11:43:55 INFO mapreduce.Job:  map 55% reduce 5% 14/10/04 11:44:05 INFO mapreduce.Job:  map 56% reduce 5% 14/10/04 11:44:16 INFO mapreduce.Job:  map 57% reduce 5% 14/10/04 11:44:32 INFO mapreduce.Job:  map 58% reduce 5% 14/10/04 11:44:47 INFO mapreduce.Job:  map 59% reduce 5% 14/10/04 11:44:51 INFO mapreduce.Job:  map 60% reduce 5% 14/10/04 11:45:09 INFO mapreduce.Job:  map 61% reduce 5% 14/10/04 11:45:25 INFO mapreduce.Job:  map 62% reduce 5% 14/10/04 11:45:48 INFO mapreduce.Job:  map 63% reduce 5% 14/10/04 11:46:06 INFO mapreduce.Job:  map 64% reduce 5% 14/10/04 11:46:15 INFO mapreduce.Job:  map 64% reduce 6% 14/10/04 11:46:36 INFO mapreduce.Job:  map 65% reduce 6% 14/10/04 11:47:10 INFO mapreduce.Job:  map 66% reduce 6% 14/10/04 11:47:24 INFO mapreduce.Job:  map 67% reduce 6% 14/10/04 11:47:38 INFO mapreduce.Job:  map 68% reduce 6% 14/10/04 11:47:42 INFO mapreduce.Job:  map 69% reduce 6% 14/10/04 11:47:50 INFO mapreduce.Job:  map 70% reduce 6% 14/10/04 11:47:57 INFO mapreduce.Job:  map 71% reduce 6% 14/10/04 11:48:03 INFO mapreduce.Job:  map 72% reduce 6% 14/10/04 11:48:07 INFO mapreduce.Job:  map 73% reduce 6% 14/10/04 11:48:24 INFO mapreduce.Job:  map 74% reduce 6% 14/10/04 11:48:52 INFO mapreduce.Job:  map 75% reduce 6% 14/10/04 11:48:58 INFO mapreduce.Job:  map 75% reduce 7% 14/10/04 11:49:17 INFO mapreduce.Job:  map 76% reduce 7% 14/10/04 11:49:43 INFO mapreduce.Job:  map 77% reduce 7% 14/10/04 11:50:06 INFO mapreduce.Job:  map 78% reduce 7% 14/10/04 11:50:18 INFO mapreduce.Job:  map 79% reduce 7% 14/10/04 11:50:25 INFO mapreduce.Job:  map 79% reduce 8% 14/10/04 11:50:55 INFO mapreduce.Job:  map 80% reduce 8% 14/10/04 11:50:58 INFO mapreduce.Job:  map 81% reduce 8% 14/10/04 11:51:18 INFO mapreduce.Job:  map 82% reduce 8% 14/10/04 11:51:24 INFO mapreduce.Job:  map 83% reduce 8% 14/10/04 11:51:45 INFO mapreduce.Job:  map 84% reduce 8% 14/10/04 11:52:05 INFO mapreduce.Job:  map 85% reduce 8% 14/10/04 11:52:17 INFO mapreduce.Job:  map 85% reduce 9% 14/10/04 11:52:28 INFO mapreduce.Job:  map 86% reduce 9% 14/10/04 11:52:31 INFO mapreduce.Job:  map 87% reduce 9% 14/10/04 11:52:34 INFO mapreduce.Job:  map 88% reduce 9% 14/10/04 11:52:38 INFO mapreduce.Job:  map 89% reduce 9% 14/10/04 11:52:42 INFO mapreduce.Job:  map 90% reduce 9% 14/10/04 11:52:59 INFO mapreduce.Job:  map 91% reduce 9% 14/10/04 11:53:28 INFO mapreduce.Job:  map 92% reduce 9% 14/10/04 11:53:55 INFO mapreduce.Job:  map 93% reduce 9% 14/10/04 11:53:58 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000097_0, Status : FAILED 14/10/04 11:54:00 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000099_0, Status : FAILED 14/10/04 11:54:00 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000098_0, Status : FAILED 14/10/04 11:54:00 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000100_0, Status : FAILED 14/10/04 11:54:00 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000101_0, Status : FAILED 14/10/04 11:54:05 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000097_1, Status : FAILED 14/10/04 11:54:05 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_r_000000_0, Status : FAILED Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#5 at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:121) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:380) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for output/attempt_1412391426441_0002_r_000000_0/map_20.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getInputFileForWrite(YarnOutputFiles.java:213) at org.apache.hadoop.mapreduce.task.reduce.OnDiskMapOutput.<init>(OnDiskMapOutput.java:61) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:257) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:411) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:341) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:165)
14/10/04 11:54:06 INFO mapreduce.Job:  map 93% reduce 0% 14/10/04 11:54:09 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000099_1, Status : FAILED 14/10/04 11:54:09 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000098_1, Status : FAILED 14/10/04 11:54:18 INFO mapreduce.Job:  map 94% reduce 0% 14/10/04 11:54:41 INFO mapreduce.Job:  map 96% reduce 0% 14/10/04 11:54:41 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000101_1, Status : FAILED Error: java.io.IOException: Spill failed at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.checkSpillException(MapTask.java:1540) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1447) at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for attempt_1412391426441_0002_m_000101_1_spill_0.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getSpillFileForWrite(YarnOutputFiles.java:159) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1573) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.access$900(MapTask.java:852) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer$SpillThread.run(MapTask.java:1510)
14/10/04 11:54:41 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000100_1, Status : FAILED Error: java.io.IOException: Spill failed at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.checkSpillException(MapTask.java:1540) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1447) at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for attempt_1412391426441_0002_m_000100_1_spill_0.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getSpillFileForWrite(YarnOutputFiles.java:159) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1573) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.access$900(MapTask.java:852) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer$SpillThread.run(MapTask.java:1510)
14/10/04 11:54:41 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000099_2, Status : FAILED Error: java.io.IOException: Spill failed at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.checkSpillException(MapTask.java:1540) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1447) at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for attempt_1412391426441_0002_m_000099_2_spill_0.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getSpillFileForWrite(YarnOutputFiles.java:159) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1573) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.access$900(MapTask.java:852) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer$SpillThread.run(MapTask.java:1510)
14/10/04 11:54:41 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_m_000097_2, Status : FAILED Error: java.io.IOException: Spill failed at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.checkSpillException(MapTask.java:1540) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1447) at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for attempt_1412391426441_0002_m_000097_2_spill_0.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getSpillFileForWrite(YarnOutputFiles.java:159) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1573) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.access$900(MapTask.java:852) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer$SpillThread.run(MapTask.java:1510)
14/10/04 11:54:42 INFO mapreduce.Job:  map 94% reduce 0% 14/10/04 11:54:42 INFO mapreduce.Job: Task Id : attempt_1412391426441_0002_r_000000_1, Status : FAILED Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#3 at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:121) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:380) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157) Caused by: org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find any valid local directory for output/attempt_1412391426441_0002_r_000000_1/map_4.out at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:398) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:150) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:131) at org.apache.hadoop.mapred.YarnOutputFiles.getInputFileForWrite(YarnOutputFiles.java:213) at org.apache.hadoop.mapreduce.task.reduce.OnDiskMapOutput.<init>(OnDiskMapOutput.java:61) at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:257) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:411) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:341) at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:165)
14/10/04 11:54:44 INFO mapreduce.Job:  map 100% reduce 100% 14/10/04 11:54:51 INFO mapreduce.Job: Job job_1412391426441_0002 failed with state FAILED due to: Task failed task_1412391426441_0002_m_000097 Job failed as tasks failed. failedMaps:1 failedReduces:0
14/10/04 11:54:52 INFO mapreduce.Job: Counters: 34 File System Counters FILE: Number of bytes read=13102192174 FILE: Number of bytes written=26212068108 FILE: Number of read operations=0 FILE: Number of large read operations=0 FILE: Number of write operations=0 HDFS: Number of bytes read=12608837345 HDFS: Number of bytes written=0 HDFS: Number of read operations=288 HDFS: Number of large read operations=0 HDFS: Number of write operations=0 Job Counters  Failed map tasks=14 Failed reduce tasks=2 Killed map tasks=5 Launched map tasks=115 Launched reduce tasks=2 Other local map tasks=12 Data-local map tasks=103 Total time spent by all maps in occupied slots (ms)=18567852 Total time spent by all reduces in occupied slots (ms)=1205016 Map-Reduce Framework Map input records=246865790 Map output records=246865790 Map output bytes=12608458902 Map output materialized bytes=13102191058 Input split bytes=9984 Combine input records=0 Spilled Records=493731580 Failed Shuffles=0 Merged Map outputs=0 GC time elapsed (ms)=180426 CPU time spent (ms)=3391620 Physical memory (bytes) snapshot=25874554880 Virtual memory (bytes) snapshot=86517563392 Total committed heap usage (bytes)=19113443328 File Input Format Counters  Bytes Read=12608827361 Exception in thread "main" java.io.IOException: Job failed! at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:836) at com.fiveone.game.GameLoginLog.main(GameLoginLog.java:38) 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)

解决办法： 在mapred-site.xml配置文件中加上一条配置： <property>                 <name>mapreduce.reduce.shuffle.memory.limit.percent</name>                 <value>0.20</value>                 <description>Expert: Maximum percentage of the in-memory limit that a single shuffle can consume</description>  </property> 默认mapreduce.reduce.shuffle.memory.limit.percent配置的值为：0.25    ，可以根据自己的情况适量降低这个值。

出现这个问题的原因有很多种，要视情况去解决，下面是在网上找的一些解决方案： 日志报错：attempt_201207232344_0002_r_000000_0, Status : FAILED
org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#1
 Error reading task outputConnection refused
No job jar file set.  User classes may not be found. See Job or Job#setJar(String).
12/07/23 23:51:42 INFO mapreduce.JobSubmitter: Cleaning up the staging area hdfs://127.0.0.1:9000/tmp/hadoop-root/mapred/staging/root/.staging/job_201207232344_0003
在网上找了下解决办法，大致有几种可能的原因： 1、 Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out. 系统设置有关，文件较大，无法分配大内存
2、机器位数是64位导致这个问题
3、/etc/hosts 里面没有配master的hostname  4、防火墙没关
        问题1我安装网上方法，对配置文件做了修改： vim /etc/security/limits.conf  加入 * soft nofile 102400  * hard nofile 409600
vim /etc/pam.d/login  加入：session    required     /lib/security/pam_limits.so但是还是没有办法解决
问题三：由于我是伪分布式，所以只要配本机就行，看了下配置了hostname
问题四：setup下看了我的防火墙，发现防火墙有两个，一个是firework一个是selinux，第一个关了，第二个没关
最后在我重启虚拟机后，终于可以正常运行，但是是不是就是第四步弄好的呢，在我重新打开selinux后，再次运行，依然正常，我想应该不是selinux没关的可能，至于到底什么原因，可能是问题1
来源： <http://blog.sina.com.cn/s/blog_757dbe670101gpry.html>  
Too many fetch-failures
13/02/25 21:20:48 INFO mapreduce.Job: Task Id : attempt_201302230043_0022_r_000000_0, Status : FAILED
org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#4
        at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:124)
        at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:362)
        at org.apache.hadoop.mapred.Child$4.run(Child.java:223)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1153)
        at org.apache.hadoop.mapred.Child.main(Child.java:217)
Caused by: java.io.IOException: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out.
        at org.apache.hadoop.mapreduce.task.reduce.ShuffleScheduler.checkReducerHealth(ShuffleScheduler.java:253)
        at org.apache.hadoop.mapreduce.task.reduce.ShuffleScheduler.copyFailed(ShuffleScheduler.java:187)
        at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:347)
        at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:251)
        at org.apache.hado
    几个可能原因：1、hostname 配置   2、我的错误（选用的数据压缩方法不对，造成错误）： job.getConfiguration().setClass("mapred.map.runner.class", MultithreadedMapRunner.class, MapRunnable.class);
job.getConfiguration().setBoolean("mapreduce.map.output.compress", true);

6、hadoop执行JOB在reduce阶段报了下面的错误： 

1. Error: org.apache.hadoop.mapreduce.task.reduce.Shuffle$ShuffleError: error in shuffle in fetcher#4   
2. at org.apache.hadoop.mapreduce.task.reduce.Shuffle.run(Shuffle.java:121)   
3. at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:380)   
4. at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:165)   
5. at java.security.AccessController.doPrivileged(Native Method)   
6. at javax.security.auth.Subject.doAs(Subject.java:415)   
7. at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)   
8. at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:160)   
9. Caused by: java.lang.OutOfMemoryError: Java heap space   
10. at org.apache.hadoop.io.BoundedByteArrayOutputStream.<init>(BoundedByteArrayOutputStream.java:56)   
11. at org.apache.hadoop.io.BoundedByteArrayOutputStream.<init>(BoundedByteArrayOutputStream.java:46)   
12. at org.apache.hadoop.mapreduce.task.reduce.InMemoryMapOutput.<init>(InMemoryMapOutput.java:63)   
13. at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.unconditionalReserve(MergeManagerImpl.java:297)   
14. at org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl.reserve(MergeManagerImpl.java:287)   
15. at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyMapOutput(Fetcher.java:411)   
16. at org.apache.hadoop.mapreduce.task.reduce.Fetcher.copyFromHost(Fetcher.java:341)   
17. at org.apache.hadoop.mapreduce.task.reduce.Fetcher.run(Fetcher.java:165)  

解决方法： 

修改mapred-site.xml配置中的mapreduce.reduce.shuffle.memory.limit.percent参数 

1. <property>  
2.    <name>mapreduce.reduce.shuffle.memory.limit.percent</name>  
3.   <value>0.25</value>  
4.   <description>Expert: Maximum percentage of the in-memory limit that a  
5.   single shuffle can consume</description>  
6. </property>  

这个值默认是0.25，可以根据需要适当的减小这个值。
来源： <http://tangjunliang.iteye.com/blog/2024510>
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