Deploying Hadoop clusters on Linux HA-QJM Chapter

Environment

The basic article needs 4 machines (one Namenode, three datanode);

HA Chapter requires 8 machines: two Namenode (one for active NN, the other for standby nn), three Datanode, three zookeeper (you can also omit these three, zookeeper daemon on other machines). It actually requires 3 journalnode, but because it's relatively lightweight, it's deployed here on the Datanode.

The following information is configured on three zookeeper machines:

1 Creating a Hadoop user

2 do ssh password-free login

3 Modifying host Names

4 Installing the JDK

5 Download Zookeeper installation package

: Http://mirror.nus.edu.sg/apache/zookeeper

Download zookeeper-3.4.6 to/opt/directory, unzip

6 Modifying/etc/profile

Export zoo_home=/opt/zookeeper-3.4.6
Export Zoo_log_dir=/opt/zookeeper-3.4.6/logs

To make it effective:
Source/etc/profile

7 Setting up Zookeeper data storage directory:

Mkdir/opt/zookeeper-3.4.6/data

8 Create the configuration file under $zoo_home/conf:

VI zoo.cfg Add the following content:

# The number of milliseconds of each tick
ticktime=2000
# The number of ticks that 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 are just
# example Sakes.
Datadir=/opt/zookeeper-3.4.6/data
# The port at which the clients would connect
clientport=2181
server.1=10.9.214.167:31316:31317
server.2=10.9.214.18:31316:31317
server.3=10.9.214.211:31316:31317

9 Create the file myID in the/opt/zookeeper-3.4.6/data/directory, and write the content, Zookeeper1 write 1,zookeeper2 write 2,zookeeper3 write 3, such as:

Echo 1 >/opt/zookeeper-3.4.6/data/myid

10 Start the Zookeeper service:

CD $ZOO _home

./bin/zkserver.sh Start

11 Verification

To test whether the zookeeper cluster is successful, execute the following command in the $zoo_home directory, if no error indicates that the cluster was created successfully:

./bin/zkcli.sh-server localhost:31315

Hadoop configuration files only need to modify core-site.xml and Hdfs-site.xml

Configure Core-site.xml

<property>

<name>hadoop.tmp.dir</name>

<value>/opt/hadoop-2.6.0/tmp</value>

</property>

<property>

<name>fs.default.name</name>

<value>hdfs://10.9.214.151:9000</value>

</property>

<property>
<name>hadoop.proxyuser.root.hosts</name>
<value>10.9.214.151</value>
</property>
<property>
<name>hadoop.proxyuser.root.groups</name>
<value>*</value>
</property>

<property>
<name>fs.defaultFS</name>
<value>hdfs://cluster_haohzhang</value>
</property>
<property>
<name>ha.zookeeper.quorum</name>
<value>10.9.214.167:2181,10.9.214.18:2181,10.9.214.211:2181</value>
</property>

Configure Hdfs-site.xml
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/opt/hadoop-2.6.0/hdfs/name</value>
</property>

<property>
<name>dfs.dataname.data.dir</name>
<value>file:/opt/hadoop-2.6.0/hdfs/data</value>
</property>

<property>
<name>dfs.replication</name>
<value>3</value>
</property>
<property>
<name>dfs.nameservices</name>
<value>cluster_haohzhang</value>
</property>
<property>
<name>dfs.ha.namenodes.cluster_haohzhang</name>
<value>nn1,nn2</value>
</property>
<property>
<name>dfs.namenode.rpc-address.cluster_haohzhang.nn1</name>
<value>10.9.214.151:8020</value>
</property>
<property>
<name>dfs.namenode.rpc-address.cluster_haohzhang.nn2</name>
<value>10.9.214.15:8020</value>
</property>
<property>
<name>dfs.namenode.http-address.cluster_haohzhang.nn1</name>
<value>10.9.214.151:50070</value>
</property>
<property>
<name>dfs.namenode.http-address.cluster_haohzhang.nn2</name>
<value>10.9.214.15:50070</value>
</property>
<property>

<property>
<name>dfs.namenode.shared.edits.dir</name>
<value>qjournal://10.9.214.158:8485;10.9.214.160:8485;10.9.214.149:8485/cluster_haohzhang</value>
</property>
<property>
<name>dfs.client.failover.proxy.provider.cluster_haohzhang</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.methods</name>
<value>sshfence</value>
</property>
<property>
<name>dfs.ha.fencing.ssh.private-key-files</name>
<value>/home/hadoop/.ssh/id_rsa</value>
</property>
<property>
<name>dfs.journalnode.edits.dir</name>
<value>/opt/hadoop-2.6.0/journalnode</value>
</property>
<property>
<name>dfs.ha.automatic-failover.enabled</name>
<value>true</value>
</property>

Operation Details

1 Remove all Namenode and Datanode,journalnode on the metadata first

2 starting three Journalnode processes

hadoop-daemon.sh Start Journalnode

3 Formatting Namenode

Performed on a namenode:

HDFs Namenode-format

This step will connect the Journalnode, and the Journalnode will be formatted as well.

4 start HDFs on the namenode that you just formatted:

CD $HADOOP _home/sbin;./start-dfs.sh

5 Perform on another namenode:

HDFs Namenode-bootstrapstandby

6 Verifying manual fail over

Execute on any one of the Namenode:

HDFs Haadmin-help <command>

can see the command usage, here we use

HDFs haadmin-getservicestate Nn1hdfs haadmin-getservicestate nn2

Gets the status of two namenode in two states: Standby, active

To manually toggle the status:

HDFs haadmin-failover nn1 nn2

Success, NN2 becomes active state.

7 Automatic switching with zookeeper

7.1 Initialize ZKFC on one of the Namenode

HDFs Zkfc-formatzk

This step attempts to connect to port 2181 on zookeeper and creates a znode inside the zookeeper

7.2 Starting HDFs on the Namenode

CD $HADOOP _home;./start-dfs.sh

7.3 Verify that the process has started successfully

[Email protected] sbin]$ JPS
12277 NameNode
12871 Jps
12391 Dfszkfailovercontroller

[Email protected] hadoop-2.6.0]$ JPS
7698 DataNode
7787 Journalnode
7933 Jps

7.4 Verifying failover automatic switching

Kill all Hadoop processes on the active Namenode:

Kill-9 <pid of Nn>

Then see if another namenode has changed from standby to Active state,

Note: In the configuration file, the health state is detected every 5 minutes by default

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Deploying Hadoop clusters on Linux HA-QJM Chapter