How to Install Apache Cassandra on CentOS 8

Apache Cassandra is an open-source NoSQL database system designed to handle a large amount of data. It supports clusters spanning multiple data centers and high availability with no single point of failure. It offers a lot of features including, Highly Scalable, Distributed, Replication Support, Fault-tolerant, MapReduce support, Query language, and many more. If you are looking for scalability and high availability without compromising performance then Apache Cassandra is the best choice for you.

In this tutorial, we will show you how to install Apache Cassandra on CentOS 8.

Prerequisites

• A CentOS 8 VPS (we’ll be using our SSD 2 VPS plan)
• Access to the root user account (or access to an admin account with root privileges)

Step 1: Log in to the Server & Update the Server OS Packages

First, log in to your CentOS 8 server via SSH as the root user:

ssh root@IP_Address -p Port_number

You will need to replace ‘IP_Address‘ and ‘Port_number‘ with your server’s respective IP address and SSH port number. Additionally, replace ‘root’ with the username of the admin account if necessary.

Before starting, you have to make sure that all CentOS packages installed on the server are up to date. You can do this by running the following commands:

dnf update -y

Step 2: Install Java

Apache Cassandra requires Java 8 to be installed in your system. You can install it by running the following command:

dnf install java-1.8.0-openjdk-devel -y

After installing Java 8, verify the installed version of Java with the following command:

java -version

You should see the following output:

openjdk version "1.8.0_272"
OpenJDK Runtime Environment (build 1.8.0_272-b10)
OpenJDK 64-Bit Server VM (build 25.272-b10, mixed mode)

Step 3: Install Apache Cassandra

By default, Apache Cassandra is not available in the CentOS 8 default repo. So you will need to create a repo for that. You can create it with the following command:

nano /etc/yum.repos.d/cassandra.repo

Add the following lines:

[cassandra]
name=Apache Cassandra
baseurl=https://www.apache.org/dist/cassandra/redhat/311x/
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://www.apache.org/dist/cassandra/KEYS

Save and close the file then install the Apache Cassandra with the following command:

dnf install cassandra -y

Step 4: Create a Systemd Service File For Apache Cassandra

Next, you will need to create a systemd service file to manage the Cassandra service. You can create it with the following command:

nano /etc/systemd/system/cassandra.service

Add the following lines:

[Unit]
Description=Apache Cassandra
After=network.target

[Service]
PIDFile=/var/run/cassandra/cassandra.pid
User=cassandra
Group=cassandra
ExecStart=/usr/sbin/cassandra -f -p /var/run/cassandra/cassandra.pid
Restart=always

[Install]
WantedBy=multi-user.target

Save and close the file then reload the systemd daemon with the following command:

systemctl daemon-reload

Next, start the Cassandra service and enable it to start at system reboot:

systemctl start cassandra
systemctl enable cassandra

Next, verify the Apache Cassandra with the following command:

nodetool status

If everything is fine, you should get the following output:

Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address    Load       Tokens       Owns (effective)  Host ID                               Rack
UN  127.0.0.1  70.69 KiB  256          100.0%            560b5524-2293-4872-a2d5-03c9c1f62f94  rack1

Step 5: Connect to Cassandra with CQL

Cassandra Query Language (CQL) is a query language for the Apache Cassandra database. It is used for communicating with the Apache Cassandra database. You can use the cqlsh utility to interact with Cassandra through CQL. But, cqlsh requires Python 2 to be installed in your system. You can install it with the following command:

dnf install python2
alternatives --set python /usr/bin/python2

Next, run the following command to access the CQL:

cqlsh

Once connected, you should get the following output:

Connected to Test Cluster at 127.0.0.1:9042.
 [cqlsh 5.0.1 | Cassandra 3.11.9 | CQL spec 3.4.4 | Native protocol v4]
 Use HELP for help.
 cqlsh> 

Step 6: Rename Cassandra Cluster Name

By default, the Cassandra cluster is set to “Test Cluster”. You can change it through the cqlsh:

First, connect to the CQL using the following command:

cqlsh

Next, change the cluster name with the following command:

UPDATE system.local SET cluster_name = 'My Cluster' WHERE KEY = 'local';

Next, exit from the CQL with the following command:

exit

Next, open the Cassandra default configuration file and change the cluster name:

nano /etc/cassandra/default.conf/cassandra.yaml

Change the following line:

cluster_name: 'My Cluster'

Save and close the file then flush the system cache and restart the Cassandra service to apply the changes:

nodetool flush system
systemctl restart cassandra

Congratulations! you have successfully installed Apache Cassandra on CentOS 8.

Follow this guide for installing Apache Cassandra on Ubuntu 20.04

Of course, you don’t have to do any of this if you use one of our Linux VPS Hosting services, in which case you can simply ask our expert Linux admins to setup this for you. They are available 24×7 and will take care of your request immediately.

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