Steps to install Cassandra on Linux

In this blog post, we’ll look into the process of installing the Cassandra database in a Linux environment.

Environment details are as follows :
Cassandra Version:3.11.3.5117

1. Before starting the Cassandra Installation we have to make sure that Java is installed in our machine.

[root@localhost ~]# java -version
java version “1.8.0_241”
Java(TM) SE Runtime Environment (build 1.8.0_241-b07)
Java HotSpot(TM) 64-Bit Server VM (build 25.241-b07, mixed mode)
[root@localhost ~]#

2.Download the software from Datastax website using the below link :

https://downloads.datastax.com/#ddac
https://downloads.datastax.com/#enterprise

3. Create one “Cassandra” user at the OS level to manage Cassandra Binaries :

[root@localhost ~]# useradd cassandra

as if we try to install Cassandra using root user, in that case, we will get below error :

[root@localhost bin]# ./cassandra
Running Cassandra as root user or group is not recommended – please start Cassandra using a different system user.
If you really want to force running Cassandra as root, use -R command line option.
[root@localhost bin]#

4.Copy Cassandra software tar file to a Linux server and extract this zip file :

Login to user Cassandra and extract software files.

[root@localhost ~]# su – cassandra
[cassandra@localhost ~]$ ls -ltr
-rw-rw-r–. 1 cassandra cassandra 50529803 Jan 29 2020 ddac-5.1.17-bin.tar.gz
[cassandra@localhost ~]$ tar -xvf ddac-5.1.17-bin.tar.gz

5. In order to perform Single node cluster installation, we need to execute the “Cassandra” binary which is located under the “bin” directory.

[cassandra@localhost ~]$ ll
total 49352
drwxr-xr-x. 9 cassandra cassandra 4096 Sep 30 16:49 ddac-5.1.17
-rw-rw-r–. 1 cassandra cassandra 50529803 Jan 29 2020 ddac-5.1.17-bin.tar.gz
[cassandra@localhost ~]$ cd ddac-5.1.17

[cassandra@localhost ddac-5.1.17]$ ll
total 564
drwxr-xr-x. 2 cassandra cassandra 4096 Sep 30 16:44 bin
-rw-r–r–. 1 cassandra cassandra 4832 Sep 30 16:44 CASSANDRA-14092.txt
-rw-r–r–. 1 cassandra cassandra 17653 Sep 30 16:44 CHANGES-DSE.txt
-rw-r–r–. 1 cassandra cassandra 364468 Sep 30 16:44 CHANGES.txt
drwxr-xr-x. 2 cassandra cassandra 4096 Sep 30 16:44 conf
drwxr-xr-x. 2 cassandra cassandra 4096 Sep 30 16:44 interface
drwxr-xr-x. 3 cassandra cassandra 4096 Sep 30 16:44 lib
drwxrwxr-x. 2 cassandra cassandra 4096 Sep 30 16:49 licenses
-rw-r–r–. 1 cassandra cassandra 26187 Sep 30 16:44 LICENSE.txt
-rw-r–r–. 1 cassandra cassandra 120798 Sep 30 16:44 NEWS.txt
-rw-r–r–. 1 cassandra cassandra 2811 Sep 30 16:44 NOTICE.txt
drwxr-xr-x. 3 cassandra cassandra 4096 Sep 30 16:44 pylib
drwxr-xr-x. 4 cassandra cassandra 4096 Sep 3

[cassandra@localhost ddac-5.1.17]$ cd bin/
[cassandra@localhost bin]$ ./cassandra

Upon executing above command it creates a “Data” directory under the installation directory location and creates following directories.

[cassandra@localhost ddac-5.1.17]$ cd data/
[cassandra@localhost data]$ ll
total 16
drwxrwxr-x. 2 cassandra cassandra 4096 Jan 29 02:33 commitlog
drwxrwxr-x. 7 cassandra cassandra 4096 Jan 29 02:34 data
drwxrwxr-x. 2 cassandra cassandra 4096 Jan 29 02:33 hints
drwxrwxr-x. 2 cassandra cassandra 4096 Jan 29 02:33 saved_caches
[cassandra@localhost data]$

In case if we want to change the location of the above directories in that case before executing “./Cassandra” binary file we can change the following parameters into the cassandra.yaml configuration file.

When the directory locations are excluded or commented out in the cassandra.yaml, Cassandra uses the default locations:

• data_file_directories: installation_location/data/data
• commitlog_directory: installation_location/data/commitlog
• saved_caches_directory: installation_location/data/saved_caches
• hints_directory: installation_location/data/hints
• cdc_raw_directoryinstallation_location/data/cdc_raw

6.Once the setup is ready we can verify the status of Cassandra database using below command:

[cassandra@localhost ddac-5.1.17]$ cd bin/
[cassandra@localhost bin]$ pwd
/home/cassandra/ddac-5.1.17/bin
[cassandra@localhost bin]$ ./nodetool status

Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
— Address Load Tokens Owns (effective) Host ID Rack
UN 127.0.0.1 103.48 KiB 256 100.0% 581e9b09-c55f-4c4b-9525-d5f9a570f2bd rack1

[cassandra@localhost bin]$

We can refer below link in order to understand more about “./nodetool status” command:

===========================
https://docs.datastax.com/en/dse/6.0/dse-admin/datastax_enterprise/tools/nodetool/toolsStatus.html
===========================

Happy Learning 🙂