Installing hadoop 2.4.0 on Ubuntu server
Installing hadoop 2.4.0
First of all, THESE ARE IMPORTANT FOR INDRODUCTION
*Ubuntu server 14.04
*VM in VirtualBox with 1GB RAM
*SWAP SPACE : SELECT more than 2 GB
Up-to-date system.
[crayon-6684c69956486659713394/]
Moreover, it is advisable not to run Hadoop services through a general-purpose user, so the next step consists in adding a group hadoop
and a user hadoop-user
belonging to that group
[crayon-6684c6995648e757904698/]
Installing Java
The mentioned tutorials suggest a potentially unsafe procedure in order to install the jdk through apt-get
,
[crayon-6684c69956490204048228/]
Finally, a couple of environment variables should be set up so that the java executables are in $PATH
and hadoop knows where java has been installed: this is easily accomplished adding
[crayon-6684c69956493537781180/]
at the end of /etc/profile <<< We need to edit that to set automatically JAVA PATH
[crayon-6684c699564a2521471883/]
Setup SSH
All communications with Hadoop are encrypted via SSH, thus the corresponding server should be installed:
[crayon-6684c699564a4780575779/]
and the hadoop-user
must be associated to a key pair and subsequently granting its access to the local machine:
[crayon-6684c699564a6831239057/]
Now hadoop-user
should be able to access via ssh to localhost
without ( WE SET THE PASS = “null”)providing a password:
[crayon-6684c699564a8354137980/]
Disable IPV6
Hadoop and IPV6 do not agree on the meaning of 0.0.0.0
address,
LOOK AT : ??>>>>> /etc/sysctl.conf
[crayon-6684c699564aa040423680/]
REBOOT SYSTEM
CONTROL
[crayon-6684c699564ac809842236/]
Hadoop
Download and install Hadoop
Download hadoop-2.4.0.tar.gz, unpack it and move the results in /usr/local
, adding a symlink using the more friendly name hadoop
and changing ownership of the directory contents to the hadoop-user
user:
[crayon-6684c699564af254726742/]
Setup the dedicated user environment
Switch to the hadoop-user
user and add the following lines at the end of ~/.bashrc
:
[crayon-6684c699564b1837531290/]
To have the new environment variables in place,
1- reload .bashrc
through “source .bashrc"
2- then open /usr/local/hadoop/etc/hadoop/hadoop-env.sh
,
3- uncomment the line setting JAVA_HOME
and set its value to the jdk directory:
[crayon-6684c699564b3064961595/]
Configure Hadoop
Before being able to actually use the hadoop file system it is necessary to modify some configuration files inside /usr/local/hadoop/etc/hadoop
All such files follow the an XML format, and the updates should concern the top-level node configuration
(likely empty after the hadoop installation). Specifically:
- in
yarn-site.xml
:
[crayon-6684c699564b5365018469/]
- look in
core-site.xml
:
[crayon-6684c699564b7707304473/]
- look in
mapred-site.xml
[crayon-6684c699564b9258656079/]
- nano
hdfs-site.xml
:
[crayon-6684c699564bb097985791/]
Run these commands.
[crayon-6684c699564bd146378221/]
Formatting the distributed file system
USER should be hadoop user
[crayon-6684c699564bf019605071/]
Find the these 2 file and run
start-dfs.sh
start-yarn.sh
[crayon-6684c699564c1137931110/]
[crayon-6684c699564c3182253258/]