手把手Linux高可hadoop集群的搭建

高可用集群的搭建

在搭建高可用集群之前，如果搭建了完全分布式hadoop，先执行stop-all.sh停掉所有的服务，只保留jdk和zookeeper的2个服务，然后再去搭建。

目标：

1. 高可用集群简介
2. 部署Hadoop高可用集群

一．高可用集群简介

1. HDFS高可用集群
2. YARN高可用集群

二．部署高可用集群

先分别在每一个机器中建文件夹Hadoop313-HA

mkdir -p /export/servers/hadoop313-HA

1. 规划Hadoop高可用集群

2. 安装Hadoop

在hadoop01的/export/servers目录下安装hadoop,并使用mv指令改名为hadoop313-HA

3. 修改系统环境变量

vi /etc/profile
# 然后在尾部添加
export HADOOP_HOME=/export/servers/hadoop313-HA
export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin

source /etc/profile  #让文件生效

4. 修改配置文件

1）配置Hadoop运行时环境 vi hadoop-env.sh

export  JAVA_HOME=/export/servers/jdk1.8.0_241
export  HDFS_NAMENODE_USER=root
export  HDFS_DATANODE_USER=root
export  HDFS_JOURNALNODE_USER=root
export  HDFS_ZKFC_USER=root
export  YARN_RESOURCEMANAGER_USER=root
export  YARN_NODEMANAGER_USER=root 

2）配置Hadoop vi core-site.xml

<configuration>
<property>
        <name>dfs.replication</name>
        <value>3</value>
</property>
<property>
        <name>dfs.namenode.name.dir</name>
        <value>/export/data/hadoop313-HA/namenode</value>
</property>
<property>
        <name>dfs.datanode.data.dir</name>
        <value>/export/data/hadoop313-HA/datanode</value>
</property>
<property>
        <name>dfs.nameservices</name>
        <value>ns1</value>
</property>
<property>
    <name>dfs.ha.namenodes.ns1</name>
    <value>nn1,nn2</value>
</property>
<property>
    <name>dfs.namenode.rpc-address.ns1.nn1</name>
    <value>hadoop01:9000</value>
</property>
<property>
    <name>dfs.namenode.http-address.ns1.nn1</name>
    <value>hadoop01:9870</value>
</property>
<property>
    <name>dfs.namenode.rpc-address.ns1.nn2</name>
    <value>hadoop02:9000</value>
</property>
<property>
    <name>dfs.namenode.http-address.ns1.nn2</name>
    <value>hadoop02:9870</value>
</property>
<property>
    <name>dfs.namenode.shared.edits.dir</name>
    <value>qjournal://hadoop01:8485;hadoop02:8485;hadoop03:8485/ns1</value>
</property>
<property>
    <name>dfs.journalnode.edits.dir</name>
    <value>/export/data/journaldata</value>
</property>
<property>
    <name>dfs.ha.automatic-failover.enabled</name>
    <value>true</value>
</property>
<property>
    <name>dfs.client.failover.proxy.provider.ns1</name>
    <value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
<property>
    <name>dfs.permissions.enable</name>
    <value>false</value>
</property>
<property>
    <name>dfs.ha.fencing.methods</name>
    <value>
        sshfence
        shell(/bin/true)
    </value>
</property>
<property>
    <name>dfs.ha.fencing.ssh.private-key-files</name>
    <value>/root/.ssh/id_rsa</value>
</property>
<property>
    <name>dfs.ha.fencing.ssh.connect-timeout</name>
    <value>30000</value>
</property>
</configuration>

4）配置MapReduce vi mapred-site.xml

<configuration>
<property>
 <name>mapreduce.framework.name</name>
 <value>yarn</value>
</property>
<property>
 <name>yarn.app.mapreduce.am.env</name>
 <value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
<property>
 <name>mapreduce.map.env</name>
 <value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
<property>
 <name>mapreduce.reduce.env</name>
 <value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
</configuration>

5）配置YARN vi yarn-site.xml

<configuration>
<!-- Site specific YARN configuration properties -->
<property>
    <name>yarn.resourcemanager.ha.enabled</name>
    <value>true</value>
</property>
<property>
    <name>yarn.resourcemanager.cluster-id</name>
    <value>jyarn</value>
</property>
<property>
    <name>yarn.resourcemanager.ha.rm-ids</name>
    <value>rm1,rm2</value>
</property>
<property>
    <name>yarn.resourcemanager.hostname.rm1</name>
    <value>hadoop01</value>
</property>
<property>
    <name>yarn.resourcemanager.hostname.rm2</name>
    <value>hadoop02</value>
</property>
<property>
    <name>yarn.resourcemanager.zk-address</name>
    <value>hadoop01:2181,hadoop02:2181,hadoop03:2181</value>
</property>
<property>
    <name>yarn.nodemanager.aux-services</name>
    <value>mapreduce_shuffle</value>
</property>
<property>
    <name>yarn.resourcemanager.recovery.enabled</name>
    <value>true</value>
</property>
<property>
    <name>yarn.resourcemanager.store.class</name>
    <value>org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore</value>
</property>
</configuration>

6）配置Hadoop从节点运行的虚拟机

5. 分发Hadoop安装目录

scp  -r  /export/servers/hadoop313-HA  root@hadoop02:/export/servers/
scp  -r  /export/servers/hadoop313-HA root@hadoop03:/export/servers/

6. 分发系统环境变量文件,并使用source生效

scp  /etc/profile   root@hadoop02:/etc/
scp  /etc/profile   root@hadoop03:/etc/

7. 启动Hadoop高可用集群

1）分别在虚拟机hadoop01、hadoop02和hadoop03中启动JournalNode

hdfs  --daemon  start  journalnode 

2）在虚拟机hadoop01上格式化HDFS文件系统

hdfs   namenode   -format

3）同步NameNode

scp  -r  /export/data/hadoop313-HA/namenode/   hadoop02:/export/data/hadoop313-HA/
scp  -r  /export/data/hadoop313-HA/namenode/   hadoop03:/export/data/hadoop313-HA/ 

注意：同步NameNode是为了确保初次启动HDFS时两个NameNode存储的FSImage文件一致。并且此操作只在初次启动Hadoop高可用集群之前执行。

4）格式化ZKFC

为了确保ZooKeeper集群能够通过ZKFC为HDFS提供高可用，在****初次启动****Hadoop高可用集群之前需要进行格式化ZKFC的操作

hdfs   zkfc   -formatZK

5）启动HDFS

start-dfs.sh

6）启动YARN

start-yarn.sh 

8. 查看集群状态信息

9. 测试主备切换

【测试1】：关闭hadoop01中状态为active的NameNode

hdfs  --daemon  stop  namenode

此时，重新查看NameNode的状态，*发现hadoop01无法访问，hadoop02备胎转正*

【测试2】：关闭hadoop01中状态为active的ResourceManager

yarn  --daemon  stop  resourcemanager 

此时，重新查看ResourceManager的状态，*发现hadoop01无法访问，hadoop02备胎转正*