Big Data（五）关于Hadoop的HA的实践搭建

JoinNode 分布在node01,node02,node03

1.停止之前的集群

2.免密：node01,node02

node02:
cd ~/.ssh
ssh-keygen -t dsa -P '' -f ./id_dsa
cat id_dsa.pub >> authorized_keys
scp ./id_dsa.pub node01:`pwd`/node02.pub
node01:
cd ~/.ssh
cat node02.pub >> authorized_keys

3.zookeeper 集群搭建 java语言开发（需要jdk）

node02:
            tar xf zook....tar.gz
            mv zoo...    /opt/bigdata
            cd /opt/bigdata/zoo....
            cd conf
            cp zoo_sample.cfg  zoo.cfg
            vi zoo.cfg
                dataDir=/var/bigdata/hadoop/zk
                server.=node02::
                server.=node03::
                server.=node04::
            mkdir /var/bigdata/hadoop/zk
            echo  >  /var/bigdata/hadoop/zk/myid
            vi /etc/profile
                export ZOOKEEPER_HOME=/opt/bigdata/zookeeper-3.4.
                export PATH=$PATH:$JAVA_HOME/bin:$HADOOP_HOME/bin:$HADOOP_HOME/sbin:$ZOOKEEPER_HOME/bin
            . /etc/profile
            cd /opt/bigdata
            scp -r ./zookeeper-3.4.  node03:`pwd`
            scp -r ./zookeeper-3.4.  node04:`pwd`
        node03:
            mkdir /var/bigdata/hadoop/zk
            echo  >  /var/bigdata/hadoop/zk/myid
            *环境变量
            . /etc/profile
        node04:
            mkdir /var/bigdata/hadoop/zk
            echo  >  /var/bigdata/hadoop/zk/myid
            *环境变量
            . /etc/profile

        node02~node04:
            zkServer.sh start

4.配置hadoop的core和hdfs

core-site.xml
        <property>
          <name>fs.defaultFS</name>
          <value>hdfs://mycluster</value>
        </property>

         <property>
           <name>ha.zookeeper.quorum</name>
           <value>node02:,node03:,node04:</value>
         </property>

    hdfs-site.xml
        #下面是重命名
        <property>
        <name>dfs.replication</name>
        <value></value>
        </property>
        <property>
        <name>dfs.namenode.name.dir</name>
        <value>/var/bigdata/hadoop/ha/dfs/name</value>
        </property>
        <property>
        <name>dfs.datanode.data.dir</name>
        <value>/var/bigdata/hadoop/ha/dfs/data</value>
        </property>
        #以下是  一对多，逻辑到物理节点的映射
        <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>node01:</value>
        </property>
        <property>
          <name>dfs.namenode.rpc-address.mycluster.nn2</name>
          <value>node02:</value>
        </property>
        <property>
          <name>dfs.namenode.http-address.mycluster.nn1</name>
          <value>node01:</value>
        </property>
        <property>
          <name>dfs.namenode.http-address.mycluster.nn2</name>
          <value>node02:</value>
        </property>

        #以下是JN在哪里启动，数据存那个磁盘
        <property>
          <name>dfs.namenode.shared.edits.dir</name>
          <value>qjournal://node01:8485;node02:8485;node03:8485/mycluster</value>
        </property>
        <property>
          <name>dfs.journalnode.edits.dir</name>
          <value>/var/bigdata/hadoop/ha/dfs/jn</value>
        </property>

        #HA角色切换的代理类和实现方法，我们用的ssh免密
        <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_dsa</value>
        </property>

        #开启自动化： 启动zkfc
         <property>
           <name>dfs.ha.automatic-failover.enabled</name>
           <value>true</value>
         </property>

5.分发两个配置文件

6.开启1,2,3台的journalnode

hadoop-daemon.sh start journalnode

7.选择一个NN 做格式化

hdfs namenode -format

8.启动该NN的namenode

hadoop-daemon.sh start namenode 

9.在另一台NN进行同步

hdfs namenode -bootstrapStandby

10.在node01下格式化zk

hdfs zkfc  -formatZK

11.启动

start-dfs.sh    

12.验证

kill -  xxx
        a)杀死active NN
        b)杀死active NN身边的zkfc
        c)shutdown activeNN 主机的网卡 ： ifconfig eth0 down
            2节点一直阻塞降级
            如果恢复1上的网卡   ifconfig eth0 up
            最终 2 变成active