How to Install Cassandra on Ubuntu 16.04 LTS

Apache Cassandra is a free open-source database system that is NoSQL based. Meaning Cassandra does not use the table model seen in MySQL, MSSQL or PostgreSQL, but instead uses a cluster model. It’s designed to handle large amounts of data and is highly scalable. We will be installing Cassandra and its pre-requisites, Oracle Java, and if necessary the Cassandra drivers.

Pre-Flight Check

  • We are logged in as root on an Ubuntu 16.04 VPS powered by Liquid Web!
  • Apache Cassandra and this article expect that you are using Oracle Java Standard Edition 8, as opposed to OpenJDk . Verify your Java version by typing the command below into your terminal:

java --version

  • At the time of this article, Python 2.7.11 and later versions will need to install updated Cassandra drivers to fix a known bug with the cqlsh command. You can check your Python version similar to checking your Java version:

python --version

  • If you have Python 2.7.11+ or later, download the required driver by running the pip command. You will need pip installed. Within this tutorial, we will show you how to install pip. However, pip is usually pre-installed with Python by default.

Step 1: Install Oracle Java (JRE)

Cassandra requires your using Oracle Java SE (JRE) installed on your server. First, you will have to add Personal Package Archives to make the (JRE) package available.

sudo add-apt-repository ppa:webupd8team/java

After entering this command, it may prompt you to hit enter to continue.
Once it completes update the package database using the following:

sudo apt-get update

You can now install Oracle JRE with the following:
sudo apt-get install oracle-java8-set-default

A pink screen prompts you to agree to the terms and conditions of JRE. Hit enter to continue from this screen and accept the terms and conditions in the next screen.

Java Installer Screen

 

Once successfully installed verify the default version of Java by typing:

java -version

You’ll receive the following or something very similar :

Java Version Output

 

Step 2: Installing Apache Cassandra

First, we have to install the Cassandra repository to /etc/apt/sources.list.d/cassandra.sources.list directory by running following command (When we made this article Cassandra 3.6 was the current version. You may need to edit this line to reflect the latest release by updating the 36x value. For example, use 37x if Cassandra 3.7 is the newest version.):
echo "deb http://www.apache.org/dist/cassandra/debian 36x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.sources.list

Next, run the cURL command to add the repository keys :

curl https://www.apache.org/dist/cassandra/KEYS | sudo apt-key add -

We can now update the repositories:

sudo apt-get update

 

Note
If you get the following error: GPG error: http://www.apache.org 36x InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY A278B781FE4B2BDA
Add the public key by running the following command:
sudo apt-key adv --keyserver pool.sks-keyservers.net --recv-key A278B781FE4B2BDARepeat the update to the repositories:
sudo apt-get update

Finally, finish installing by entering the following:
sudo apt-get install cassandra

Verify the installation of Cassandra by running:
nodetool status

The desired output will show UN meaning everything is up and running normally.

Verifying Cassandra is Installed

 

Step 3: Connect with cqlsh

If you have an older version of Python before 2.7.11, you’ll skip this step and start using Cassandra with the cqlsh command. Good for you! You have successfully installed Cassandra!
cqlsh

You should see something similar to this:
Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.6 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help.

Note
For future reference, Cassandra’s configuration file, data directory and logs can be found in:

  • /etc/cassandra is the default file configuration location.
  • /var/log cassandra and /var/lib cassandra are the default log and data directories location.

However, if you get the following error,

Connection error: (‘Unable to connect to any servers’, {‘127.0.0.1’: TypeError(‘ref() does not take keyword arguments’,)}),

you’ll update the Cassandra drivers. These drivers have a known bug with Cassandra and later versions of Python. Check your Python version by typing:
python --version

Luckily, I am going to show you how you can fix this error in 3 easy steps by downloading the drivers.

 

Step 3a: First we will need pip installed. If you don’t have it already, you can get it with the following command.

sudo apt-get install python-pip

 

Step 3b: Once pip is installed, run the following to install the new Cassandra driver. Please note this command may take a while to execute. Grab a snack and wait for it to complete. It can take 5-10 minutes to install fully.

pip install cassandra-driver

 

Step 3c: Finally disable the embedded driver by entering :

export CQLSH_NO_BUNDLED=true

You should now be able to run the cqlsh command.

cqlsh

You should see this if successful :

Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.6 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help.

To exit cqlsh type exit:
cqlsh> exit

Congrats! You have successfully installed Cassandra!

Note

Cassandra should start automatically, but you’ll want to stop Cassandra to make any additional configuration changes. Start and stop it with the following:

sudo service cassandra start
sudo service cassandra stop

How To Install Oracle Java 8 in Ubuntu 16.04

Pre-Flight Check

  1. Open the terminal and log in as root.  If you are logged in as another user, you will need to add sudo before each command.
  2. Working on a Linux Ubuntu 16.04 server
  3. No installations of previous Java versions

Step 1:  Update & Upgrade

It is advised to update your system by copy and pasting the command below.  Be sure to accept the update by typing Y when asked to continue:

apt-get update && apt-get upgrade

 

Step 2: Install the Repository

WebUpd8 Team Personal Package Archive (PPA), a third party repository,  allows us to download the package necessary for Java 8 installation.  Press Enter to continue the installation.

add-apt-repository ppa:webupd8team/java

Once again, update your package list.

apt-get update

 

Step 3: Install Java 8

Use the apt-get command to install Oracle’s Java 8 via their installer:

apt-get install oracle-java8-installer

 

Click Y to continue and press Enter to agree to the licensing agreement.

 

Select Yes and hit the Enter key.

 

Step 4: Verify Java 8 is Installed

java -version

Output:

java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

 

It’s essential to know the path of our Java installation for our applications to function. Where is Java installed? Run this command to find its path:update-alternatives --config java

Output:

~# update-alternatives --config java
There is 1 choice for the alternative java (providing /usr/bin/java).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-8-oracle/jre/bin/java 1081 auto mode
* 1 /usr/lib/jvm/java-8-oracle/jre/bin/java 1081 manual mode

 

Copy the highlighted path from the second row: /usr/lib/jvm/java-8-oracle/jre/bin/java/.  After copying, open the file /etc/environment and add in the path of your Java installation to the end of your file.

vim /etc/environment

JAVA_HOME="/usr/lib/jvm/java-8-oracle/jre/bin/java"

 

Save the file by hitting ESC button and type :wq to execute the command below to recognize the changes to the file:

source /etc/environment

 

You should now see the path of installation when using the $Java_Home variable:

echo $JAVA_HOME

Output:

~# echo $JAVA_HOME
/usr/lib/jvm/java-8-oracle/jre/bin/java

 

How To Install Apache Tomcat 8 on Ubuntu 16.04

Apache Tomcat is used to deploy and serve JavaServer Pages and Java servlets. It is an open source technology based off Apache.

Pre-Flight Check

  • This document assumes you are installing Apache Tomcat on Ubuntu 16.04.
  • Be sure you are logged in as root user.

Installing Apache Tomcat 8

Step 1: Create the Tomcat Folder

Logged in as root, within the opt folder make a directory called tomcat and cd into that folder after completion.

mkdir /opt/tomcat

cd /opt/tomcat

 

Step 2: Install Tomcat Through Wget

Click this link to the Apache Tomcat 8 Download site. Place you cursor under 8.5.32  Binary Distributions, right click on the tar file and select copy link address (as shown in the picture below). At the time of this article Tomcat 8 is the newest version but feel free to pick whatever version is more up-to-date.

Tomcat 8's Download Page

Next from your server, use wget command to download the tar to  the tomcat folder from the URL you copied in the previous step:

wget http://apache.spinellicreations.com/tomcat/tomcat-8/v8.5.32/bin/apache-tomcat-8.5.32.tar.gz

Note
You can down the file to your local desktop, but you’ll then want to transfer the file to your Liquid Web server. If assistance is needed, check out this article: Using SFTP and SCP Instead of FTP

After the download completes, decompress the file in your tomcat folder:

tar xvzf apache-tomcat-8.5.32.tar.gz

 

Step 3: Install Java

Before you can use Tomcat you’ll have to install the Java Development Kit (JDK). Beforehand, check to see if Java is installed:

java -version

If that command returns the following message then Java has yet to be installed:
The program 'java' can be found in the following packages:

To install Java, simply run the following command (and at the prompt enter Y to continue):
apt-get install default-jdk

 

Step 4: Configure .bashrc file

Set the environment variables in .bashrc with the following command:

vim ~/.bashrc

Add this information to the end of the file:
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64
export CATALINA_HOME=/opt/tomcat/apache-tomcat-8.5.32

Note
Verify your file paths! If you downloaded a different version or already installed Java, you may have to edit the file path or name. Older versions of Java may say java-7-openjdk-amd64 instead of java-1.8.0-openjdk-amd64 . Likewise, if you installed Tomcat in a different folder other then /opt/tomcat (as suggested) you’ll indicate the path in your bash file and edit the lines above.

Save your edits and exit from the .bashrc file, then run the following command to register the changes:

. ~/.bashrc

 

Step 5: Test Run

Tomcat and Java should now be installed and configured on your server. To activate Tomcat, run the following script:

$CATALINA_HOME/bin/startup.sh

You should get a result similar to:

Using CATALINA_BASE: /opt/tomcat
Using CATALINA_HOME: /opt/tomcat
Using CATALINA_TMPDIR: /opt/tomcat/temp
Using JRE_HOME: /usr/lib/jvm/java-7-openjdk-amd64/
Using CLASSPATH: /opt/tomcat/bin/bootstrap.jar:/opt/tomcat/bin/tomcat-juli.jar
Tomcat started

 

To verify that Tomcat is working visit the ip address of you server:8080 in a web browser. For example http://127.0.0.1:8080.

Apache Tomcat 8 Verification Page

 

How To Install Apache Tomcat 7 on Ubuntu 16.04

Apache Tomcat is used to deploy and serve JavaServer Pages and Java servlets. It is an open source technology based off Apache.
Pre-Flight Check

  • This document assumes you are installing Apache Tomcat on Ubuntu 16.04.
  • Be sure you are logged in as root user.

Installing Tomcat 7

Step 1: Create the Tomcat Folder

Logged in as root, within the opt folder make a directory called tomcat and cd into that folder after completion.

mkdir /opt/tomcat
cd /opt/tomcat

 

Step 2: Install Tomcat Through Wget

Click this link to the Apache Tomcat 7 Download site. Place your cursor under 7.0.90 Binary Distributions, right click on the tar.gz file and select Copy Link Address (as shown in the picture below).  At the time of this article Tomcat 7 is the newest version but feel free to pick whatever version is more up-to-date.

Tomcat Version 7.0.90

Next, from your server, use wget command to download the tar to  the tomcat folder from the URL you copied in the previous step:

wget http://www.trieuvan.com/apache/tomcat/tomcat-7/v7.0.90/bin/apache-tomcat-7.0.90.tar.gz

Note
You can down the file to your local desktop, but you’ll then want to transfer the file to your Liquid Web server. If assistance is needed, check out this article: Using SFTP and SCP Instead of FTP

After the download completes, decompress the file in your Tomcat folder:

tar xvzf apache-tomcat-7.0.90.tar.gz

You will end up with a file called apache-tomcat-7.0.90.

 

Step 3: Install Java

Before you can use Tomcat, you’ll have to install the Java Development Kit (JDK). Beforehand, check to see if Java is installed:

java -version
If that command returns the following message then Java has yet to be installed:
The program 'java' can be found in the following packages:
To install Java, simply run the following command (and at the prompt enter Y to continue:
apt-get install default-jdk

 

Step 4: Configure .bashrc file

Set the environment variables in .bashrc with the following command:

vim ~/.bashrc
Add this information to the end of the file:
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64
export CATALINA_HOME=/opt/tomcat/apache-tomcat-7.0.90

Note
Verify your file paths! If you downloaded a different version or already installed Java, you may have to edit the file path or name. Older versions of Java may say java-7-openjdk-amd64 instead of java-1.8.0-openjdk-amd64 . Likewise, if you installed Tomcat in a different folder other then /opt/tomcat (as suggested) you’ll indicate the path in your bash file and edit the lines above.

Save your edits and exit from the .bashrc file, then run the following command to register the changes:

. ~/.bashrc

 

Step 5: Test Run

Tomcat and Java should now be installed and configured on your server. To activate Tomcat, run the following script:

$CATALINA_HOME/bin/startup.sh

You should get a result similar to:
Using CATALINA_BASE: /opt/tomcat
Using CATALINA_HOME: /opt/tomcat
Using CATALINA_TMPDIR: /opt/tomcat/temp
Using JRE_HOME: /usr/lib/jvm/java-7-openjdk-amd64/
Using CLASSPATH: /opt/tomcat/bin/bootstrap.jar:/opt/tomcat/bin/tomcat-juli.jar
Tomcat started.

 

To verify that Tomcat is working by visiting the IP address of your server:8080 in a web browser. For example http://127.0.0.1:8080.

Tomcat 7.0.90 Test Page

 

How to Install Oracle Java 8 on Ubuntu 12.04 LTS

Pre-Flight Check
  • These instructions are intended specifically for installing Oracle Java 8 on Ubuntu 12.04 LTS.
  • I’ll be working from a Liquid Web Core Managed Ubuntu 12.04 LTS server with Apache and PHP installed, and I’ll be logged in as non-root user. If you need more information then visit our tutorial on How to Add a User and Grant Root Privileges on Ubuntu 12.04 LTS.

Continue reading “How to Install Oracle Java 8 on Ubuntu 12.04 LTS”

How to Install Oracle Java 8 on Ubuntu 14.04 LTS

Pre-Flight Check
  • These instructions are intended specifically for installing Oracle Java 8 on Ubuntu 14.04 LTS.
  • I’ll be working from a Liquid Web Core Managed Ubuntu 14.04 LTS server with Apache and PHP installed, and I’ll be logged in as non-root user. If you need more information then visit our tutorial on How to Add a User and Grant Root Privileges on Ubuntu 14.04 LTS.

Continue reading “How to Install Oracle Java 8 on Ubuntu 14.04 LTS”

How To Install Cassandra on CentOS 6

Apache Cassandra is a NoSQL database intended for storing large amounts of data in a decentralized, highly available cluster. NoSQL refers to a database with a data model other than the tabular relations used in relational databases such as MySQL, PostgreSQL, and Microsoft SQL.

Pre-Flight Check
  • These instructions are intended for installing Cassandra 2 on a single CentOS 6 node.
  • I’ll be working from a Liquid Web Core Managed CentOS 6.4 server, and I’ll be logged in as root.
  • You may be able to skip to Step #2 if you already have a stable version of Java 7 (preferably the Oracle/Sun JVM). Check to see if your server already has Java installed by running the following command: java -version
  • Continue reading “How To Install Cassandra on CentOS 6”