1 准备工作

• 修改服务器名，修改/etc/hosts等
• SSH免秘钥（互信）
• JDK 1.8+
• Zookeeper集群

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2 集群配置

配置参考：HDFS High Availability Using the Quorum Journal Manager
Hadoop集群配置都在{hadoop_home}/etc/hadoop目录，HDFS集群部署需要修改的有下面几个配置文件：

• core-site.xml
• hadoop-env.sh
• hdfs-site.xml
• workers

2.1 配置core-site.xml

<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://mycluster</value>
        　　<description>HDFS的URI，文件系统://namenode标识:端口号</description>
    </property>
    <property>
        <name>hadoop.tmp.dir</name>
        <value>/opt/tomas/data/hadoop/tmp</value>
        <description>namenode上本地的hadoop临时文件夹</description>
    </property>
    <property>
        <name>ha.zookeeper.quorum</name>
        <value>192.216.105.249:2181,192.216.105.250:2181,192.216.105.251:2181</value>
        <description>Zookeeper地址</description>
    </property>
</configuration>

2.2 配置hadoop-env.sh

主要声明配置JAVA_HOME

export JAVA_HOME=/usr/java/default

export HDFS_NAMENODE_USER="root"
export HDFS_DATANODE_USER="root"
export HDFS_ZKFC_USER="root"
export HDFS_JOURNALNODE_USER="root"

2.2 配置hdfs-site.xml

<configuration>
  <property>
        <name>dfs.ha.automatic-failover.enabled</name>
        <value>true</value>
    </property>
    <property>
        <name>dfs.replication</name>
        <value>1</value>
    </property>
    <property>
        <name>dfs.namenode.name.dir</name>
        <value>file:/opt/data/hadoop/hdfs/name</value>
    </property>
    <property>
        <name>dfs.datanode.data.dir</name>
        <value>file:/opt/data/hadoop/hdfs/data</value>
    </property>
    <property>
        <name>dfs.nameservices</name>
        <value>mycluster</value>
    </property>
    <property>
        <name>dfs.ha.namenodes.mycluster</name>
        <value>nn1,nn2,nn3</value>
    </property>
    <property>
        <name>dfs.namenode.rpc-address.mycluster.nn1</name>
        <value>192.216.105.242:13122</value>
    </property>
    <property>
        <name>dfs.namenode.rpc-address.mycluster.nn2</name>
        <value>192.216.105.243:13122</value>
    </property>
    <property>
        <name>dfs.namenode.rpc-address.mycluster.nn3</name>
        <value>192.216.105.244:13122</value>
    </property>
    <property>
        <name>dfs.namenode.http-address.mycluster.nn1</name>
        <value>192.216.105.242:13123</value>
    </property>
    <property>
        <name>dfs.namenode.http-address.mycluster.nn2</name>
        <value>192.216.105.243:13123</value>
    </property>
    <property>
        <name>dfs.namenode.http-address.mycluster.nn3</name>
        <value>192.216.105.244:13123</value>
    </property>
    <property>
        <name>dfs.namenode.shared.edits.dir</name>
        <value>qjournal://192.216.105.242:13124;192.216.105.243:13124;192.216.105.244:13124/tomascluster</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>sshfence</value>
    </property>
    <property>
        <name>dfs.ha.fencing.ssh.private-key-files</name>
        <value>/root/.ssh/id_rsa</value>
    </property>
    <property>
        <name>dfs.journalnode.edits.dir</name>
        <value>/opt/data/hadoop/journalnode</value>
    </property>
</configuration>

2.2 配置workers

192.216.105.242
192.216.105.243
192.216.105.244
192.216.105.245
192.216.105.246

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3 集群启动

1. 在所有journalnode节点上启动journalnode，本例中是192.216.105.242~244：

bin/hdfs --daemon start journalnode

2. 随意一个namenode节点服务器执行格式化

bin/hdfs namenode -format

3. 启动上一步格式化的namenode

bin/hdfs --daemon start namenode

4. 另外两个namenode执行同步信息

bin/hdfs namenode -bootstrapStandby

5. 格式化zookeeper节点

bin/hdfs zkfc -formatZK

6.启动HDFS集群

start-dfs.sh

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3 集群验证

命令查看

bin/hdfs haadmin -getAllServiceState

分别访问三个namenode的web页面，端口为hdfs-site.xml中配置的dfs.namenode.http-address端口，可以发现一个为active，另外两个为standby。

Hadoop3-HDFS-HA-validate.png