Start Hodoop for the first time

Start Step:

1. To modify a Hadoop configuration file
   

Conf/mapred-site.xml, add the following:

<property> <name>mapred.job.tracker</name> <value>localhost:9001</value> &L T;/property>

Conf/core-site.xml, add the following:

<property> <name>fs.default.name</name> <value>hdfs://localhost:9000</value> </property>

Conf/hdfs-site.xml, add the following:

<property> <name>dfs.replication</name> <value>1</value> </property> <property> <name>dfs.permissions</name> <value>false</value> </proper Ty>

conf/hadoop-env.sh, add the following:

Export java_home=/usr/lib/jvm/jdk1.6.0_45

Where java_home points to my JDK installation path

2. Set Password-free login

Since Hadoop starts the start/Stop script with ssh command to start the relevant daemon, in order to avoid each start/stop Hadoop input password authentication, you need to set up password-free login, the following steps:

1) Open the shell terminal and enter the following command:

SSH-KEYGEN-T RSA

The public key file Id_rsa.pub and the private key file are generated under the "~/.ssh/" directory Id_rsa

1) Copy the contents of the public key file id_rsa.pub to the same directory as the Authroized_keys file:

CD ~/.ssh/cat id_rsa.pub >> Authroized_keys

3. Start Hadoop

1) format HDFs:

./hadoop Namenode-format

2) Start Hadoop

./start-all.sh

In my Ubuntu desktop version, the following error is reported because SSH server is not installed by default:

Connect to host localhost Port 22:connection refused

The workaround is to install SSH server to

Connect to host localhost Port 22:connection refused

After successful startup, use the command to confirm that Hadoop has started successfully.

[Email protected]:~/release-1.0.1/bin$ netstat-ant|grep 50030tcp6 0 0::: 50030:::*                LISTEN [email protected]:~/release-1.0.1/bin$ netstat-ant|grep 50070tcp6 0 0::: 50070 :::* LISTEN

Access localhost:50030/,localhost:50070/with a browser to view the operation of MapReduce and HDFs.

Start Hodoop for the first time