In this article I want to show installiation of Cassandra on Ubuntu Linux.

Youi have to install Java 8 and Java 11. We will use Java 11.

I. Install dependencies for Apache Cassandra and Java.

1. Update packages:

sudo apt update

2. We have to install Java 11 by command:

sudo apt install openjdk-11-jdk -y

3. install the apt-transport-https package

sudo apt install apt-transport-https

II. Adding Apache Cassandra repository and key.

1.Apache Cassandra is not available in the official Ubuntu repository, you need to add the Cassandra repository and pull the repository key before installing the database.

wget -qO- https://downloads.apache.org/cassandra/KEYS | sudo apt-key add -

2. Adding Cassandra Repo

echo "deb https://debian.cassandra.apache.org 41x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.sources.list

III. Install Cassandra

1. Updating package:

sudo apt update

2. Install the cassandra:

sudo apt install cassandra -y

3.Verify Cassandra installiation:

nodetool status

sudo systemctl status cassandra

 

IV. Basic commands for Cassandra’s manipulation

sudo systemctl status cassandra    # status of service
 
sudo systemctl start cassandra    # start cassandra service

sudo systemctl restart cassandra  # restart  cassandra service 

sudo systemctl stop cassandra   # stop cassandra service

sudo systemctl enable cassandra  # enable cassandra service

Backup cassandra settings:

sudo cp /etc/cassandra/cassandra.yaml /etc/cassandra/cassandra.yaml.backup

edit cassandra settings:

 sudo vi /etc/cassandra/cassandra.yaml
#OR
sudo gedit /etc/cassandra/cassandra.yaml[/php]

 

V. Basic CQlSH cmmands

We have to call csql from command line:

 sudo cqlsh


cqlsh> select * from dzen.users allow filtering;
 

List of commands:

CREATE KEYSPACE IF NOT EXISTS dzen WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };    # create new KeySpace dzen

use dzen;  #use dzen-keyspace

create new table users in keyspace dzen

CREATE TABLE IF NOT EXISTS users (   user_id UUID PRIMARY KEY,
                                     first_name text,
                                     last_name text,
                                     email text
);   #create new table users

insert data in users table:

INSERT INTO dzen.users (user_id, email, first_name, last_name)
VALUES (e7ae5c77-d358-4d99-b900-85902fda9bb7, 'andjei@gmail.com', 'Andjei','dudkin');

VI. Select version of Java During multi-using of version of JAVA


sudo update-alternatives --config java


for Cassandra- use Java 8 or Java 11

java version selection