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Cassandra installation

May 17, 2021 Cassandra

Table of contents

Cassandra can be accessed using cqlsh as well as drivers in different languages. /b10> This chapter describes how to set up cqlsh and java environments to use Cassandra.

Pre-installed settings

Before installing Cassandra in a Linux environment, we need to set up Linux using ssh (Secure Shell). /b10> Follow these steps to set up a Linux environment.

Create a user

Initially, it is recommended to create a separate user for Hadoop to isolate the Hadoop file system from the Unix file system. /b10> Follow these steps to create a user.

  • Use the command "su" to open the root.

  • Use the command "useradd username" to create a user from the root account.

  • You can now open an existing user account using the command "su username".

Open the Linux terminal and type the following command to create a user.

$ su
# useradd hadoop
# passwd hadoop
New passwd:
Retype new passwd

SSH settings and key generation

SSH settings are required to perform different operations on the cluster, such as startup, stop, and distributed daemon shell operations. /b10> To authenticate different users of Hadoop, you need to provide a public/private key pair for Hadoop users and share it with different users.

The following commands are used to generate key value pairs using SSH:

  • Copy the public key form to authorized_keys.
  • and provide the owner,
  • Read and authorized_keys permissions for each file.
$ ssh-keygen -t rsa
$ cat ~/.ssh/ >> ~/.ssh/authorized_keys
$ chmod 0600 ~/.ssh/authorized_keys
  • Verify SSH:
ssh localhost

Install Java

Java is a major prerequisite for Cassandra. First, you should use the following commands to verify that java exists in your system:

$ java -version

If all goes well, it will give you the following output.

java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b13)
Java HotSpot(TM) Client VM (build 25.0-b02, mixed mode)

If you don't have Java in your system, follow these steps to install Java.

Step 1

Download java from the following link (JDK slt;latest version> - X64.tar.gz): Link

The jdk-7u71-linux-x64 .tar.gz downloaded to your system.

Step 2

Usually you will find the downloaded java file in the download folder. /b10> Use the following command to verify it and unzip the jdk-7u71-linux-x64 .gz files.

$ cd Downloads/
$ ls
$ tar zxf jdk-7u71-linux-x64.gz
$ ls
jdk1.7.0_71 jdk-7u71-linux-x64.gz

Step 3

For Java to be available to all users, you must move it to the location "/usr/local /". /b10> Open root, and then type the following command.

$ su
# mv jdk1.7.0_71 /usr/local/
# exit

Step 4

To set the PATH JAVA_HOME variables, add the following command to the .bashrc file.

export JAVA_HOME = /usr/local/jdk1.7.0_71
export PATH = $PATH:$JAVA_HOME/bin

All changes are now applied to the currently running system.

$ source ~/.bashrc

Step 5

Use the following commands to configure java options.

# alternatives --install /usr/bin/java java usr/local/java/bin/java 2
# alternatives --install /usr/bin/javac javac usr/local/java/bin/javac 2
# alternatives --install /usr/bin/jar jar usr/local/java/bin/jar 2

# alternatives --set java usr/local/java/bin/java
# alternatives --set javac usr/local/java/bin/javac
# alternatives --set jar usr/local/java/bin/jar

The java-version command is now used from the terminal as described above.

Set the path

Set the path of the Cassandra path in "/.bashrc", as shown below.

[hadoop@linux ~]$ gedit ~/.bashrc

export CASSANDRA_HOME = ~/cassandra

Download Cassandra

Apache Cassandra has download links available, and Cassandra uses the following commands.

$ wget

Use the command zxvf to unzip Cassandra, as shown below.

$ tar zxvf apache-cassandra-2.1.2-bin.tar.gz.

Create a new directory called cassandra and move the contents of the downloaded file to it, as shown below.

$ mkdir Cassandra
$ mv apache-cassandra-2.1.2/* cassandra.

Configure Cassandra

Open cassandra.yaml: The file will be in Cassandra's bin directory.

$ gedit cassandra.yaml

Note: If you install Cassandra from a deb or rpm package, the profile will be located in Cassandra's /etc/cassandra directory.

The above command opens the cassandra.yaml file. /b10> Verify the following configuration. /b11> By default, these values are set to the specified directory.

  • data_file_directories“/ var / lib / cassandra / data”

  • commitlog_directory “/var/lib/cassandra/commitlog”

  • saved_caches_directory “/var/lib/cassandra/saved_caches”

Make sure that these directories exist and can be written, as shown below.

Create a directory

As a super user, create two directories / var / lib / cassandra and / var./ lib / cassandra, in which Cassandra writes its data.

[root@linux cassandra]# mkdir /var/lib/cassandra
[root@linux cassandra]# mkdir /var/log/cassandra

Grant folder permissions

The newly created folder is granted read and write permissions, as shown below.

[root@linux /]# chmod 777 /var/lib/cassandra
[root@linux /]# chmod 777 /var/log/cassandra

Start Cassandra

To start Cassandra, open the terminal window, navigate to The Cassandra home directory/home, unzip Cassandra, and then run the following command to start the Cassandra server.

$./bin/cassandra -f 

Use the -f option to tell Cassandra to keep it in the fore, rather than running as a background process. /b10> If all goes well, you can see the Cassandra server boot.

Programming environment

To programmatically set up Cassandra, download the following jar file:

  • slf4j-api-1.7.5.jar
  • cassandra-driver-core-2.0.2.jar
  • guava-16.0.1.jar
  • metrics-core-3.0.2.jar
  • netty-3.9.0.Final.jar

Put them in separate folders. /b10> For example, we're downloading these jars to a folder Cassandra_jars".

Set the class path for this folder in the .bashrc file, as shown below.

[hadoop@linux ~]$ gedit ~/.bashrc

//Set the following class path in the .bashrc file.

export CLASSPATH = $CLASSPATH:/home/hadoop/Cassandra_jars/*

Eclipse environment

Open Eclipse and create a new project called Cassandra Examples.

Right-click the project, select the build path→ configure the build path, as shown below.

Cassandra installation

It opens the property window. b20> Under the Library tab, choose to add an external JAR. b41> Navigate to the directory where you saved your jar file. /b40> Select all five jar files, and then click OK, as shown below.

Cassandra installation

Under the reference library, you can see that all the required jars have been added, as follows:

Cassandra installation

Maven relies on it

Here's a look at how to build a Cassandra project using maven .xml.

<project xmlns = "" 
   xmlns:xsi = ""  
   xsi:schemaLocation = "">