Ubuntu16.04安装配置hadoop-2.7.4

写下来自己记录下，搭hadoop的伪分布式虽然很简单，但是有比较多的坑！

1.首先去下载包，然后解压

这里就不用多做说明了

2.接下来是profile的配置，这个东西比较的烦人：

export JAVA_HOME=/opt/jdk
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

export HADOOP_HOME=/opt/hadoop-2.7.4
export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin
export HADOOP_CONF_DIR=$HADOOP_HOME/etc/hadoop
export YARN_CONF_DIR=$HADOOP_HOME/etc/hadoop这个是直接可以用的，我试过！
3.最恶心的就是下面一点了：

  hadoop配置文件：

1.core-site.xml

<configuration>
<property>
<name>hadoop.tmp.dir</name>
<value>file:/opt/hadoop-2.7.4/tmp</value>
<description>Abase for other temporary directories.</description>
</property>
<property>
<name>fs.defaultFS</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>2.hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/opt/hadoop-2.7.4/tmp/dfs/name</value>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>file:/opt/hadoop-2.7.4/tmp/dfs/data</value>
</property>
</configuration>这里你首先要把那些个文件建好,tmp,dfs/data,dfs/name
运行过程是这样的：

1.先格式化namenode:

./hadoop namenode -format
2.格式化成功就可以运行了:
./sbin/start-dfs.sh注意：但是实际上你是不能运行的报的错是这个
Starting namenodes on [localhost]
localhost: Error: JAVA_HOME is not set and could not be found.
localhost: Error: JAVA_HOME is not set and could not be found.
Starting secondary namenodes [account.jetbrains.com]
account.jetbrains.com: Error: JAVA_HOME is not set and could not be found.但是实际上你的JAVA_HOME是配置了，解决方法如下：
vi /home/hadoop-2.7.4/etc/hadoop/hadoop-env.sh 设置JAVA_HOME
vi /home/hadoop-2.7.4/etc/hadoop/mapred-env.sh 设置JAVA_HOME

去配置下这个，我被这个搞死了！