#千万注意：接下来需要在各个几点的dataDir目录下建立myid文件，内容就是相应的A，也就是说，各个ZK节点的myid文件内容不同 !!!
3.修改各个节点的环境变量
在/etc/profile文件添加：
export ZOOKEEPER_HOME=/home/yarn/Zookeeper/zookeeper-3.4.6
并为PATH加上
$ZOOKEEPER_HOME/bin
注意：export ZOOKEEPER_HOME要在PATH的上方。
下面开始修改Hadoop的配置文件：
4.修改core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://myhadoop</value>
<description>注意：myhadoop为集群的逻辑名，需与hdfs-site.xml中的dfs.nameservices一致！</description>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/home/yarn/Hadoop/hdfs2.0/tmp</value>
</property>
<property>
<name>ha.zookeeper.quorum</name>
<value>master:2181,slave1:2181,slave2:2181</value>
<description>各个ZK节点的IP/host，及客户端连接ZK的端口，该端口需与zoo.cfg中的clientPort一致！</description>
</property>
</configuration>
5.修改hdfs-site.xml
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://www.linuxidc.com/configuration.xsl"?>
<!--
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. See accompanying LICENSE file.
-->
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>dfs.nameservices</name>
<value>myhadoop</value>
<description>
Comma-separated list of nameservices.
as same as fs.defaultFS in core-site.xml.
</description>
</property>
<property>
<name>dfs.ha.namenodes.myhadoop</name>
<value>nn1,nn2</value>
<description>
The prefix for a given nameservice, contains a comma-separated
list of namenodes for a given nameservice (eg EXAMPLENAMESERVICE).
</description>
</property>
<property>
<name>dfs.namenode.rpc-address.myhadoop.nn1</name>
<value>master:8020</value>
<description>
RPC address for nomenode1 of hadoop-test
</description>
</property>
<property>
<name>dfs.namenode.rpc-address.myhadoop.nn2</name>
<value>slave1:8020</value>
<description>
RPC address for nomenode2 of hadoop-test
</description>
</property>
<property>
<name>dfs.namenode.http-address.myhadoop.nn1</name>
<value>master:50070</value>
<description>
The address and the base port where the dfs namenode1 web ui will listen on.
</description>
</property>
<property>
<name>dfs.namenode.http-address.myhadoop.nn2</name>
<value>slave1:50070</value>
<description>
The address and the base port where the dfs namenode2 web ui will listen on.
</description>
</property>
<property>
<name>dfs.namenode.servicerpc-address.myhadoop.n1</name>
<value>master:53310</value>
</property>
<property>
<name>dfs.namenode.servicerpc-address.myhadoop.n2</name>
<value>slave1:53310</value>
</property>
<property>
<name>dfs.namenode.name.dir</name>
<value>file:///home/yarn/Hadoop/hdfs2.0/name</value>
<description>Determines where on the local filesystem the DFS name node
should store the name table(fsimage). If this is a comma-delimited list
of directories then the name table is replicated in all of the
directories, for redundancy. </description>
</property>
<property>
<name>dfs.namenode.shared.edits.dir</name>
<value>qjournal://slave1:8485;slave2:8485;slave3:8485/hadoop-journal</value>
<description>A directory on shared storage between the multiple namenodes
in an HA cluster. This directory will be written by the active and read
by the standby in order to keep the namespaces synchronized. This directory
does not need to be listed in dfs.namenode.edits.dir above. It should be
left empty in a non-HA cluster.
</description>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>file:///home/yarn/Hadoop/hdfs2.0/data</value>
<description>Determines where on the local filesystem an DFS data node
should store its blocks. If this is a comma-delimited
list of directories, then data will be stored in all named
directories, typically on different devices.
Directories that do not exist are ignored.
</description>
</property>
<property>
<name>dfs.ha.automatic-failover.enabled</name>
<value>true</value>
<description>
Whether automatic failover is enabled. See the HDFS High
Availability documentation for details on automatic HA
configuration.
</description>
</property>
<property>
<name>dfs.journalnode.edits.dir</name>
<value>/home/yarn/Hadoop/hdfs2.0/journal/</value>
</property>
<property>