使用过程当中，发现hadoop的YARN-3832的bug，2.6.0中已解决，可是2.7.0中又出现了这个bug。html
15/09/28 10:22:34 INFO mapreduce.Job: Task Id : attempt_1443364253801_0310_m_000000_0, Status : FAILED Rename cannot overwrite non empty destination directory /data/hadoop/data/tmp/nm-local-dir/usercache/hadoop/filecache/60 java.io.IOException: Rename cannot overwrite non empty destination directory /data/hadoop/data/tmp/nm-local-dir/usercache/hadoop/filecache/60 at org.apache.hadoop.fs.AbstractFileSystem.renameInternal(AbstractFileSystem.java:735) at org.apache.hadoop.fs.FilterFs.renameInternal(FilterFs.java:236) at org.apache.hadoop.fs.AbstractFileSystem.rename(AbstractFileSystem.java:678) at org.apache.hadoop.fs.FileContext.rename(FileContext.java:958) at org.apache.hadoop.yarn.util.FSDownload.call(FSDownload.java:366) at org.apache.hadoop.yarn.util.FSDownload.call(FSDownload.java:62) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745)
找了很久，最终确认该问题是hadoop的bug，不是配置出错。在官网的2.7.1的release中找到了YARN-3832的bug。因此对hadoop进行升级。java
从2.7.0升级为2.7.1，升级步骤以下：shell
1.下载安装包后，下载native的64位包，替换新版本中的native。apache
2.修改2.7.1中的配置文件，保持与当前集群配置一致，修改配置文件后，分发到各台hadoop集群机器的一个临时目录中。个人配置文件列表有：core-site.xml、excludes、hadoop-env.sh、hdfs-site.xml、mapred-env.sh、mapred-site.xml、master、slaves、yarn-env.sh、yarn-site.xml服务器
3.停掉hadoop集群。oop
4.登陆每台hadoop节点的服务器，先备份hadoop的安装文件目录。而后进入hadoop安装目录，执行rm -rf bin etc include lib libexec LICENSE.txt NOTICE.txt README.txt sbin sharespa
5.将临时目录中的2.7.1的hadoop文件拷贝至安装目录。code
6.执行start-all.sh，启动hadoop集群，访问http://localhost:50070/dfshealth.html#tab-overview ，查看hadoop版本是否已更新，查看各节点状态是否正常。xml