Oracle Installation for SQOOP Import

 Till now, in our Digital Ocean Private Networking Cluster we have our nodes as below:

1 NameNode, 2 DataNodes & 1 EdgeNode/ClientNode/GatewayNode (Hadoop Binaries & Configuration files, SQOOP, HIVE)

Installing Oracle in Linux

Let us spawn a droplet in Digital Ocean:

• Distributions: CentOS 7.2 x64
• Size: 2GB /2 CPUs; 40 GB SSD Disk; 3TB Transfer
  
• Data center region: New York3. ( The Data center should be same as that, where your hadoop cluster & edge node resides in order to enable private networking )
  
• Additional Options: Check Private Networking on. (So that Sqoop in Edgenode and Datanodes in hadoop cluster can communicate with the oracle server)
  
• Hostname: oraxe
  

Finally create the droplet.

Once the droplet is up ssh to the machine. Firstly setup the /etc/hosts file correctly. Remove all the lines and add the below two lines, save and quit. In my case the Private IP address is 10.0.100.4

[root@oraxe ~]# vi /etc/hosts
10.0.100.4 oraxe
127.0.0.1 localhost

Note: The IP mentioned above in the first line is the Private IP address of the droplet in Digital Ocean not the IPv4 Public address.

Update/Install the packages for libaio, bc, flex and unzip.

[root@oraxe ~]# yum install libaio bc flex unzip

Download Oracle Express Edition from the below link:
http://www.oracle.com/technetwork/database/database-technologies/express-edition/downloads/index.html

Once you accept and license agreement Copy the URL for the download Oracle Database Express Edition 11g Release 2 for Linux x64, so that we can directly download in the server. Next we rename the file as required.

[root@oraxe ~]# wget http://download.oracle.com/otn/linux/oracle11g/xe/oracle-xe-11.2.0-1.0.x86_64.rpm.zip?AuthParam=1472010283_e868ce0dc999fce3da22a522653a185b
[root@oraxe ~]# mv oracle-xe-11.2.0-1.0.x86_64.rpm.zip\?AuthParam\=1472010283_e868ce0dc999fce3da22a522653a185b oracle-xe-11.2.0-1.0.x86_64.rpm.zip
[root@oraxe ~]# unzip -q oracle-xe-11.2.0-1.0.x86_64.rpm.zip
[root@oraxe ~]# cd Disk1
[root@oraxe Disk1]# ls	
	oracle-xe-11.2.0-1.0.x86_64.rpm  response  upgrade

Installation of Oracle mostly encounter the below error:

“This system does not meet the minimum requirements for swap space. Based on the amount of physical memory available on the system, Oracle Database 11g Express Edition requires 2048 MB of swap space. This system has 0 MB of swap space. Configure more swap space on the system and retry the installation.” Lets fix the swap space issue.

[root@oraxe Disk1]# dd if=/dev/zero of=/swapfile bs=1024M count=2
[root@oraxe Disk1]# mkswap /swapfile
[root@oraxe Disk1]# free -m | grep Swap
[root@oraxe Disk1]# swapon /swapfile
[root@oraxe Disk1]# free -m | grep Swap

 Now Let us start the Oracle Installer.

[root@oraxe Disk1]# rpm -ivh oracle-xe-11.2.0-1.0.x86_64.rpm

Once the Database Installation Completed successfully, we need to configure the database. Mostly for all the options we will choose the default value, simply by pressing Enter.

[root@oraxe Disk1]# /etc/init.d/oracle-xe configure
HTTP Port: 8088
Listener Port: 1521
SYS/SYSTEM Password: (e.g. hadoop 1234)
Start Oracle on boot: y


Once done you should see the success status as below
Starting Oracle Net Listener...Done  
Configuring database...Done  
Starting Oracle Database 11g Express Edition instance...Done  
Installation completed successfully.</enter>

The installation created the directory /u01 under which Oracle XE is installed. To set the required Oracle environment variables, use the oracle_env.sh the script included under cd /u01/app/oracle/product/11.2.0/xe/bin

[root@oraxe Disk1]# cd /u01/app/oracle/product/11.2.0/xe/bin
[root@oraxe /u01/app/oracle/product/11.2.0/xe/bin]# . ./oracle_env.sh

 This sets the environment for our current session. But in order to set the environment permanently, append the following line to the .bashrc file append the below line, save and quit.

[root@oraxe /u01/app/oracle/product/11.2.0/xe/bin]# vi .bashrc

	. /u01/app/oracle/product/11.2.0/xe/bin/oracle_env.sh

Now let’s try to access Oracle SQL*Plus utility:

[root@oraxe /u01/app/oracle/product/11.2.0/xe/bin]# sqlplus /nolog
SQL*Plus: Release 11.2.0.2.0 Production on Wed Sep 21 08:17:26 2011
Copyright (c) 1982, 2011, Oracle.  All rights reserved.

SQL> connect sys/Password as sysdba

 Now we will unlock & reset the password of a default database called HR, so that we can use the same from sqoop.

SQL> ALTER USER hr ACCOUNT UNLOCK;
SQL> ALTER USER hr IDENTIFIED BY hrpass1234;

Login to this HR account later & check the tables/data, as we will be using these tables in our sqoop import job.

To allow remote access to Oracle 11g XE GUI (as well as Application Express GUI) issue the following from SQL*Plus

SQL> EXEC DBMS_XDB.SETLISTENERLOCALACCESS(FALSE);  
SQL> exit

We will now be able to access the Oracle 11g XE Home Page GUI at http://localhost:8080/apex/f?p=4950:1

Replace localhost above with your IP as required and log in as SYSTEM and the password.

We are done with the Oracle Installation.

We need to map the Private IP address & Hostname of the Oracle Server in all the Nodes in our cluster. Once done, it’s time for us to login to our client node or edge node where we have our SQOOP installed. In the next article we will see SQOOP in action with Oracle RDBMS.