Manual HA

2,modify core-site.xml

<property>
	<name>fs.defaultFS</name>
	<value>hdfs://mycluster</value>
</property>
<property>
  	<name>hadoop.tmp.dir</name>
	<value>/home/sweeney/soft/tmp</value>
</property>
<property>
	<name>dfs.journalnode.edits.dir</name>
	<value>/home/hyxy/soft/tmp/journalnode</value>
</property>

3,modify hdfs-site.xml

<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>master:9000</value>
</property>
<property>
	<name>dfs.namenode.rpc-address.mycluster.nn2</name>
	<value>slave1:9000</value>
</property>
<property>
	<name>dfs.namenode.http-address.mycluster.nn1</name>
	<value>master:50070</value>
</property>
<property>
	<name>dfs.namenode.http-address.mycluster.nn2</name>
	<value>slave1:50070</value>
</property>
<property>
	<name>dfs.namenode.shared.edits.dir</name>
	<value>qjournal://master:8485;slave1:8485;slave2:8485/mycluster</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>/home/hyxy/.ssh/id_rsa</value>
</property>

4,(If you have formatted the new cluster, please skip to Step 6 below. NameNode，Or it's going to be enabled HA Conversion of cluster to enablement HA，Then you should run the command " hdfs namenode bootstrapStandby "take NameNode Copy the contents of the metadata directory to another unformatted NameNode Up.

hadoop-daemon.sh start namenode
hdfs namenode bootstrapStandby(Before executing this command, make sure namenode It's in the running state.

5,If you want to HA NameNode Convert to HA，Run the command " hdfs namenode -initializeSharedEdits "，This command will be used locally NameNode Initialization of Edit Data in Edit Catalog JournalNodes.

hadoop-daemon.sh stop namenode
hdfs namenode -initializeSharedEdits(Before executing this command, make sure nomenode Stop running)

6,If it's a new cluster, ignore steps 4 or 5 and go back to this article Blog Step 21, the next step is basically the same. Only step 25, before formatting, starts on each node journalnode.

hadoop-daemon.sh start journalnode

Switch one of the namenodes to active (see the status of the two namenodes on the web first)
hdfs haadmin -transitionToActive nn1
 Testing the success of uploading files

II. Automatic HA

 3,stay zookeeper Of conf Under the catalogue, modify zoo.cfg(Without this file, please zoo_sample.cfg Copy a) configuration file.

		tickTime=2000
		dataDir=/home/hyxy/soft/tmp/zookeeper
		clientPort=2181
		initLimit=5
		syncLimit=2
		server.1=master:2888:3888
		server.2=slave1:2888:3888
		server.3=slave2:2888:3888

4,take zoo.cfg Files are sent to other nodes.

scp ~/soft/zoo/conf/zoo.cfg sweeney@slave1:~/soft/zoo/conf/

Echo "1" > myid (note 1 is the ID server. 1 = master: 2888: 3888 given in the configuration file)

6,Running on each machine again zkServer.sh start，Then verify zkCli.sh Is the order successful?

zkCli.sh

7,Above manual HA In the core-site.xml Append

<property>
	<name>ha.zookeeper.quorum</name>
	<value>master:2181,slave1:2181,slave2:2181</value>
</property>

Added to hdfs-site.xml

<property>
	<name>dfs.ha.automatic-failover.enabled</name>
	<value>true</value>
</property>

8,Start cluster

start-dfs.sh

If the cluster has been started before configuration, the zkfc daemon is opened separately using the following command

hadoop-daemon.sh --script $HADOOP_PREFIX/bin/hdfs start zkfc

Kill-9 namenode's process id