1. To add the WebUpd8 Oracle Java PPA repository to the Software Sources in Debian, use the following commands:

   echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee /etc/apt/sources.list.d/webupd8team-java.list
   echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list.d/webupd8team-java.list
   apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886

2. execute command apt-get update
   1. ignore the error about "public key is not available"
3. execute command apt-get install oracle-java7-installer and answer affirmatively to "Proceed without verification" and all other installation questions
4. execute command ln -s /usr/lib/jvm/java-7-oracle /usr/lib/jvm/default-java to set Oracle's Java as a default Java on the system
5. check if java is properly installed with command java -version

Step 3: Tomcat 7 package installation:

1. execute command apt-get install tomcat7
2. start Tomcat: service tomcat7 start
3. verify that Tomcat is running properly with the command service tomcat7 status
   

1. Create a file pgdg.list in /etc/apt/sources.list.d/ with some text editor: nano /etc/apt/sources.list.d/pgdg.list and add the following line:
   deb http://apt.postgresql.org/pub/repos/apt/ wheezy-pgdg main

2. execute command: wget --quiet -O - http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | sudo apt-key add -

3. execute command apt-get update

4. execute command apt-get install postgresql postgresql-client

5. verify that PostgreSQL is running properly with the command service postgresql status

To access the application, type http://myip:8080/netvizura in your browser. The default user account with administrator privileges is: username: admin, password: admin01

Post Install Steps

After installation it is needed to tweak the configuration files in order to utilize the installed RAM to the fullest extent. The main consumers of RAM are operating system, PostgreSQL database and Tomcat. A rule of thumb for distributing memory is to split it in ratio 2:1 between PostgreSQL and Tomcat with 1 GB or more reserved for operating system. For instance:

Tweaking Tomcat memory allocation

In the following example 1 GB of RAM is allocated for Tomcat process:

1. Edit file /etc/default/tomcat7
2. Locate JAVA_OPTS environment variable that defines memory and uncomment it if it is 
commented. This line looks something like the following:
   JAVA_OPTS="-Djava.awt.headless=true -Xmx128M -XX:+UseConcMarkSweepGC"
3. Modify the -Xmx parameter to allocate additional memory to Tomcat. Additionally, set parameter -Xms to the same amount. This should look something like:
   JAVA_OPTS="-Djava.awt.headless=true -Xms1024M -Xmx1024M -XX:+UseConcMarkSweepGC"
4. Edit file /etc/init.d/tomcat7
5. Locate JAVA_OPTS environment variable that defines memory. This line looks something like the following:
   JAVA_OPTS="-Djava.awt.headless=true -Xmx128M"
6. Modify the -Xmx parameter. Additionally, set parameter -Xms to the same amount as -Xmx. This should look something like:
   JAVA_OPTS="-Djava.awt.headless=true -Xms1024M -Xmx1024M"
7. Save the file and restart Tomcat: service tomcat7 restart

Tweaking PostgreSQL

Tweaking PostgreSQL for best performance is a topic on which many books were written, but the following are some common sense suggestions. In general there are two groups of PostgreSQL tweaks that are helpful for NetVizura performance - "safe" and "unsafe" tweaks. "Safe" tweaks are those which can be applied in all cases. "Unsafe" tweaks trade reliability for performance. For the curious ones recommended reads (among countless others) are PostgreSQL Optimization Guide, PostgreSQL Tuning Guide, this article and this book.

In order to apply following tweaks edit file /etc/postgresql/PG_VERSION_NUMBER/main/postgresql.conf. You will need to restart the PostgreSQL service after done editing with command: service postgresql restart. Almost all of the following parameters are commented with carron character (#). Although these tweaks are considered "safe" do take notice of the default values. Usually you can comment out the parameter that has been changed and PostgreSQL will revert to the default value. 

PostgreSQL "safe" tweaks

In the following example it is assumed that 4 GB of RAM is allocated for PostgreSQL.

PostgreSQL "unsafe" tweaks