单namenode节点

准备

文件下载：

jdk-8u241-linux-x64.tar.gz

hadoop-3.2.0.tar.gz

节点安排：

hadoop1 → 从节点

hadoop2 → 主节点

首先确保hadoop1能够免密登录hadoop1以及hadoop2

将文件下载到/data目录下，并解压、建立软连接，最终状态如下：

修改配置

hadoop相关配置修改

core-site.xml

<configuration>
<property>
                <name>fs.defaultFS</name>
                <value>hdfs://hadoop2:9000</value>
        </property>
        <property>
                <name>hadoop.tmp.dir</name>
                <value>file:/data/hadoop/data/tmp</value>
</property>
</configuration>

hdfs-site.xml

<configuration>
   <property>
       <name>dfs.replication</name>
       <value>2</value>
   </property>
   <property>
       <name>dfs.namenode.name.dir</name>
       <value>file:/data/hadoop/data/dfs/name</value>
   </property>
   <property>
       <name>dfs.datanode.data.dir</name>
       <value>file:/data/hadoop/data/dfs/data</value>
   </property>
        <property>
                <name>dfs.namenode.secondary.http-address</name>
                <value>hadoop1:50000</value>
        </property>
</configuration>

hadoop-env.sh

新增

export JAVA_HOME=/data/jdk8

start-dfs.sh

开头新增（根据你启动用户修改，如果是root则填root）

HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root
HDFS_SECONDARYNAMENODE_USER=root

stop-dfs.sh

开头新增

HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root
HDFS_SECONDARYNAMENODE_USER=root

workers修改为

hadoop1

hadoop2

系统环境变量修改

hadoop1和hadoop2都执行

/etc/profile

新增

export JAVA_HOME=/data/jdk8
export PATH=$PATH:$JAVA_HOME/bin

export HADOOP_HOME=/data/hadoop
export PATH=$PATH:${HADOOP_HOME}/bin:${HADOOP_HOME}/sbin

修改完之后执行 source /etc/profile刷新

新建目录

hadoop1和hadoop2都执行

mkdir -p /data/hadoop/data/dfs/data
mkdir -p /data/hadoop/data/tmp
mkdir -p /data/hadoop/data/dfs/name

初始化namenode

hadoop namenode -format

启动hdfs

主节点执行

start-dfs.sh

NameNode HA

准备zookeeper二进制包

apache-zookeeper-3.5.9-bin.tar.gz

在hadoop2节点安装并启动zookeeper

修改配置文件

cp zookeeper/conf/zoo_sample.cfg zookeeper/conf/zoo.cfg

修改zoo.cfg为
# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial 
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between 
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just 
# example sakes.
dataDir=/data/zookeeper/data
# the port at which the clients will connect
clientPort=2181
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=60
#
# Be sure to read the maintenance section of the 
# administrator guide before turning on autopurge.
#
# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
#
# The number of snapshots to retain in dataDir
#autopurge.snapRetainCount=3
# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1

启动zookeeper

cd zookeeper && bin/[zkServer.sh](http://zkServer.sh) start

停止hdfs

stop-dfs.sh

修改hdfs-site.xml

新增配置：

<property>
  <name>dfs.nameservices</name>
  <value>mycluster</value>
</property>

<property>
  <name>dfs.ha.namenodes.mycluster</name>
  <value>nn1,nn2</value>
</property>

<property>
  <name>dfs.namenode.rpc-address.mycluster.nn1</name>
  <value>hadoop1:9000</value>
</property>
<property>
  <name>dfs.namenode.rpc-address.mycluster.nn2</name>
  <value>hadoop2:9000</value>
</property>
<property>
  <name>dfs.namenode.http-address.mycluster.nn1</name>
  <value>hadoop1:9870</value>
</property>
<property>
  <name>dfs.namenode.http-address.mycluster.nn2</name>
  <value>hadoop2:9870</value>
</property>
<property>
  <name>dfs.namenode.shared.edits.dir</name>
  <value>qjournal://hadoop1:8485;hadoop2:8485/mycluster</value>
</property>
<property>
  <name>dfs.journalnode.edits.dir</name>
  <value>/data/hadoop/journal/data</value>
</property>
<property>
   <name>dfs.ha.automatic-failover.enabled.mycluster</name>
   <value>true</value>
</property>
<property>
  <name>dfs.client.failover.proxy.provider.mycluster</name>
  <value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
<property>
  <name>dfs.ha.fencing.methods</name>
  <value>shell(/bin/true)</value>
</property>

修改core-site.xml

<property>
  <name>fs.defaultFS</name>
  <value>hdfs://mycluster</value>
</property>

<property>
  <name>ha.zookeeper.quorum</name>
  <value>hadoop2:2181</value>
</property>

注意：保证所有节点上所有的配置都是一样的。

启动journalnode，hadoop1和hadoop2节点都执行

hdfs --daemon start journalnode

在hadoop2节点执行

hdfs namenode -initializeSharedEdits

hadoop2节点执行格式化zk，

 hdfs zkfc -formatZK

hadoop2节点启动zkfc进程

hdfs --daemon start zkfc

hadoop2节点启动namenode

hdfs --daemon start namenode

将hadoop2节点的namenode元数据复制到Hadoop相同的目录

scp -r /data/hadoop/data/dfs/name/* hadoop1:/data/hadoop/data/dfs/name/

在Hadoop1节点执行

hdfs namenode -bootstrapStandby

hadoop1节点启动

hdfs --daemon start namenode

至此hadoop1和hadoop2已经启用了namenode的高可用特性，其通过zk自动选举。具体如下图所示：