1. in file /etc/apt/sources.list, add the following lines:

   deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main

   deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main

2. execute command apt-get update

1. 1. ignore the error about "public key is not available"

rm /var/lib/apt/lists/* -vf

apt-get update

     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

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/ trusty-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

Step 6: Verify installation

Now you can go to NetVizura web interface http://serverip:8080/netvizura.

Default login credentials:

• Username: admin
• Password: admin01

For example, if your server IP is 1.1.1.1 then point your browser to http://1.1.1.1:8080/netvizura like in the screenshot below:

Post Install Steps

Tomcat Memory Allocation 

After installation tweaking of configuration files is required in order to utilize the installed RAM to the fullest extent. The main consumers of RAM are operating system, PostgreSQL database and Tomcat. General rule 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:

During installation NetVizura automatically allocates memory for Tomcat process. The amount allocated to Tomcat process is calculated according to the formula:

(RAMtotal - 1GB) / 3 but no less than 1GB.

For instance:

However, if you need to tweak Tomcat RAM allocation differently (the example for 2048MB):

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="${JAVA_OPTS} -Xmx1024m -Xms1024m +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 -Xmx2048M -Xms2048M -XX:+UseConcMarkSweepGC"

1. 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.

parameter	recommended value	comment
max_connections	30	NetVizura rarely uses more than 10 connections simultaneously, but it is good to have some reserve
shared_buffers	1024MB	the recommended amount is RAM/4
effective_cache_size	2048MB	the recommended amount is RAM/2, possibly even RAM * 3/4
chekpoint_segments	32	for write intensive apps (as NetVizura) it should be at least 16, with 32 as safe maximum
checkpoint_completion_target	0.9
default_statistics_target	100
work_mem	8MB - 12MB	The formula used is max_connections*work_mem <= RAM/8, but using a bit more is still "safe"

PostgreSQL "unsafe" tweaks

These optimizations are considered "unsafe" since they could in very rare cases lead to data loss and/or corruption. If your VM is properly backed up we would consider the following optimizations safe. The following bring huge performance boosts to DB write process.

parameter	recommended value	comment
maitenance_work_mem	32MB	speeds up DB self clean process, not really important
wal_buffers	16MB
full_page_writes	off
fsync	off	don't wait for HDD to finish previous write operation. This brings the most benefit, but is considered potentially the most unsafe of all. If there is OS or HDD failure in exact instant when PSQL issues write command to HDD, that data will be lost and the DB itself could be corrupted. On the other hand, DB can issue several magnitude more write commands in the same time period and consider all these done, thus improving write performance immensely.
synchronous_commit	off	similarly to "fsync" but less unsafe and with less benefit
checkpoint_segments	64	how much is cached in temp files before it is issued to proper DB files. Issuing big chunks of data for write rarely is usually better for performance than issuing small chunks often