爱折腾的人总是会出线各种奇怪的问题。记得之前听一位大师讲过，我们不能踩完前进路上的所有坑前进，而应该学会怎样避开前进路上的坑，踩得坑越多，可能你的经验越丰富，但是付出的时间代价可能不是经验能换来的。我很认同这句话，但是我们学习过程中难免会踩各种各样的坑，今天这个小小的坑，让我在坑里从上午10:00，一直折腾到下午16:00+，最后实在找不出来哪里问题，决定去问大神（也算是本项目组Hadoop专家），然而他也没遇到过，从一头雾水，到解决他只用了不到10分钟，在他的面前，我深深体会到了还再学校的技术小白和公司的技术骨干之间的鸿沟（这是个容易扯着蛋的鸿沟）。
一、问题出现的原因
本来我的Hadoop2.7.2是在公司的电脑上进行配置的，因为自己回去要学习，所以就把台式机中的虚拟机都拷贝到笔记本中了，然后各种配置IP等相关的，然后就启动分布式环境了，命令：
hadoop@master$ ${HADOOP_HOME}/sbin/start.dfs.sh
现象：主节点的namenode、secondarynamenode启动成功，但是slave节点datenode启动不成功。
查看slave的输出日志，显示如下：
2016-07-28 23:12:03,301 INFO org.apache.hadoop.http.HttpServer2: Added filter static_user_filter (class=org.apache.hadoop.http.lib.StaticUserWebFilter$StaticUserFilter) to context logs
2016-07-28 23:12:03,336 INFO org.apache.hadoop.http.HttpServer2: HttpServer.start() threw a non Bind IOException
java.net.BindException: Port in use: localhost:0
at org.apache.hadoop.http.HttpServer2.openListeners(HttpServer2.java:919)
at org.apache.hadoop.http.HttpServer2.start(HttpServer2.java:856)
at org.apache.hadoop.hdfs.server.datanode.web.DatanodeHttpServer.<init>(DatanodeHttpServer.java:104)
at org.apache.hadoop.hdfs.server.datanode.DataNode.startInfoServer(DataNode.java:759)
at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:1108)
at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:428)
at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:2370)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:2257)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:2304)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:2481)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:2505)
Caused by: java.net.BindException: Cannot assign requested address
at sun.nio.ch.Net.bind0(Native Method)
at sun.nio.ch.Net.bind(Net.java:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
at org.mortbay.jetty.nio.SelectChannelConnector.open(SelectChannelConnector.java:216)
at org.apache.hadoop.http.HttpServer2.openListeners(HttpServer2.java:914)
... 10 more
……（此处省略了好多内容）
2016-07-28 23:12:03,356 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1
2016-07-28 23:12:03,363 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at slave01/192.168.75.101
************************************************************/
二、日志分析
很自然，从这个日志中提取两个关键的地方
（1）java.net.BindException: Port in use: localhost:0
（2）Caused by: java.net.BindException: Cannot assign requested address
其中第一个是现象，是说端口被占用，到底哪个端口被占用，只给出了主机localhost，并且给出了localhost的端口0，因为配置都是在台式机上面配置的，并且经过测试都是可以用的，基本可以判断，端口被占用基本上是不可能发生的（这些都是自己猜测），那么是什么导致的的？
第二个说明的失败导致的原因，说网络绑定异常，不能分配请求的地址，这个其实也没什么用。
三、自己的小经验
对于master节点都启动成功，而datenode启动不成功，我们第一时间想到的就是namenode和datenode不一致导致的。于是我们将master的namenode进行格式化，格式化操作之前需要删除data文件夹，具体参考我之前的一篇博客：Hadoop2.7.x中所有的DataNode都启动不了解决办法
但是发现还是不行，然后就各种百度，经过了一个多小时的时间，耐心也被消耗的差不多了，然后还是基本可以锁定在格式化，主从数据不一致这方面，然后我删除了namenode上面的defaultFS目录下的所有文件，我的是/opt/data/，我的core-site.xml配置如下图：
aaarticlea/png;base64,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" alt="" />
此时删除/opt/data下所有的文件，然后在执行namenode格式化操作，然后启动成功。
aaarticlea/png;base64,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" alt="" />
四、错误再次出现
错误的再次出现也意味着上述的方法行不通，然后从上午十点开始就一直折腾这个问题，中午也没睡午觉，到了下午16:00，实在解决不了了，决定去请教Hadoop布道师，他拿到这个问题，第一反映是为什么会出现这个问题，他自己也没遇到过，然后他就开始排错，最后修改了两处内容，其中第一处应该不是必要的，第二处是关键。
（1）在core-site.xml中添加了namenode 和 Datanode的目录地址，如下：
<!-- Put site-specific property overrides in this file. --> <configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://master:9000</value>
</property> <property>
<name>dfs.name.dir</name>
<value>/opt/data/namenode</value>
</property> <property> <name>dfs.data.dir</name>
<value>/opt/data/datanode</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/opt/data/tmp</value>
</property>
</configuration>
（2）重点，导致问题的根本原因，在/etc/hosts文件中
之前不知道看谁的博客，说在hosts文件中删除多余的IP与主机名的对应关系（之前貌似也是ipc通信不成功，然后删除了127.0.0.1和0.0.0.1）之后就成为了如下的样子:
但是根据提示，（1）java.net.BindException: Port in use: localhost:0
（2）Caused by: java.net.BindException: Cannot assign requested address