How To Install Apache Solr on AlmaLinux 8

In this tutorial, we will show you how to install Apache Solr on AlmaLinux 8. For those of you who didn’t know, Apache Solr is the popular, blazing-fast, open-source enterprise search platform built on Apache Lucene. Solr is designed for scalability and fault tolerance. It is widely used for enterprise search and analytics use cases and has an active development community and regular releases.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of the Apache Solr on AlmaLinux 8. You can follow the same instructions for CentOS and Rocky Linux.

Prerequisites

• A server running one of the following operating systems: AlmaLinux 8.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Apache Solr on AlmaLinux 8

Step 1. First, let’s start by ensuring your system is up-to-date.

sudo dnf update
sudo dnf upgrade
sudo dnf install epel-release

Step 2. Installing OpenJDK.

Apache Solr is written in the Java programming language. Run the following command below to install OpenJDK:

sudo dnf install java-latest-openjdk

After successful installation, verify the Java version:

java -version

Step 3. Installing Apache Solr on AlmaLinux 8.

Now we download the latest Apache Solr available package from their official download page:

wget https://downloads.apache.org/lucene/solr/8.9.0/solr-8.9.0.tgz

In this tutorial, we will verify using the SHA checksum. So download the same version of the SHA512 checksum as below:

wget https://downloads.apache.org/lucene/solr/8.9.0/solr-8.9.0.tgz.sha512

Next, calculate the SHA512 checksum of the Apache Solr archive downloaded:

gpg --print-md SHA512 solr-8.9.0.tgz

Compare the hash value with the contents of the SHA512 file downloaded:

cat solr-8.9.0.tgz.sha512

Once done, extract the downloaded Apache Solr Archive:

tar xzf solr-8.9.0.tgz

After that, install Apache Solr using the following command below:

solr-8.9.0/bin/install_solr_service.sh solr-8.9.0.tgz

To rectify the warnings during startup of service due to File and Process limits. You need to define the security limits as required by the Apache Solr Enterprise Search Server:

nano /etc/security/limits.conf

Add the following directives to this file:

...
*               soft    nofile		65000
*               hard    nofile		65000
*               soft    nproc		65000
*               hard    nproc		65000

Then, restart Apache Solr services:

sudo su - solr -c "/opt/solr/bin/solr restart"

Step 4. Configure Firewall.

Apache Solr uses default network port 8983/TCP. Therefore, you need to allow this port in the Linux firewall:

sudo firewall-cmd --add-port=8983/tcp --permanent
sudo firewall-cmd --reload

Step 5. Accessing Apache Solr on Web Interface.

Once successfully installed, open your web browser and access the Solr web interface using the URL http://your-server-ip-address:8983/solr. You should see the following screen:

Congratulations! You have successfully installed Apache Solr. Thanks for using this tutorial for installing the Apache Solr on your AlmaLinux 8 system. For additional help or useful information, we recommend you check the official Apache website.