How to Install the Sphinx Search Engine on CentOS 7

Sphinx is a free and open source full-text search engine which can be integrated into various web applications to provide rapid and high quality search results.

This article will show you how to setup a Sphinx search engine to index and search an example MariaDB database on a Vultr CentOS 7 server instance. It will give you some preliminary ideas of how to use Sphinx in your project.

Prerequisites

• Deploy a fresh CentOS 7 server instance from the Vultr control panel.
• Use a non-root sudo user to log in from your SSH terminal. See how to create a sudo user in this article.

Step 1: Update your system

sudo yum update -y && sudo reboot

After the system reboot finishes, use the same sudo user to log in again.

Step 2: Install and configure MariaDB

Sphinx can be used to search various data sources, like SQL databases, plain text files, HTML files, etc. Here, let's have a look at how to use Sphinx to perform searches upon a MariaDB database.

Install MariaDB using YUM:

sudo yum install mariadb mariadb-server

Start the MariaDB service:

sudo systemctl start mariadb.service
sudo systemctl enable mariadb.service

For security purposes, perform the secure MySQL installation:

sudo /usr/bin/mysql_secure_installation

Finish this procedure in accordance with the following instructions:

Enter current password for root (enter for none): Press Enter
Set root password? [Y/n]: Input Y, then press Enter
New password: Input a new password for root, press Enter
Re-enter new password: Input the same password again, then press Enter
Remove anonymous users? [Y/n]: Input Y, then press Enter
Disallow root login remotely? [Y/n]: Input Y, then press Enter
Remove test database and access to it? [Y/n]: Input Y, then press Enter
Reload privilege tables now? [Y/n]: Input Y, then press Enter

After the secure MySQL installation finishes, you will have to set a new password for the MySQL user "root". In this tutorial, I'll refer to it as "yourpassword".

Step 3: Install the latest Sphinx

In order to install the latest version of Sphinx, you need to download the proper rpm package from the Sphinx official website:

cd ~
wget http://sphinxsearch.com/files/sphinx-2.2.10-1.rhel7.x86_64.rpm
sudo yum install sphinx-2.2.10-1.rhel7.x86_64.rpm

Step 4: Create a database for testing

Use the following MySQL commands to create a database named "test":

mysql -u root -p -e "CREATE DATABASE test"

When you are asked to provide a password, input the one you set earlier and then press Enter.

Now, import test data from a Sphinx example sql file:

mysql -u root -p test < /usr/share/doc/sphinx-2.2.10/example.sql

Again, input the same password and then press Enter to finish the import.

Step 5: Configure Sphinx

Open the Sphinx configuration file /etc/sphinx/sphinx.conf:

sudo vi /etc/sphinx/sphinx.conf

For now, you only need to setup the MySQL username sql_user and the password sql_pass, which would be:

sql_user                = root
sql_pass                = yourpassword

Save and quit:

:wq

Step 6: Start the indexer and searchd daemons

Both indexer and searchd are important components of Sphinx. Indexer is in charge of gathering data from the data source, and searchd is the part of the search engine which actually handles searches.

Be sure to run the following commands orderly, or you will encounter errors.

sudo indexer --all
sudo searchd

To update the index status regularly, create a cron job:

sudo crontab -e

Input the following entry:

0 * * * * /usr/bin/indexer --rotate --config /etc/sphinx/sphinx.conf --all

Save and quit:

:wq

This cron job will update the index status hourly.

Step 7: Test your Sphinx search engine

You can use a predefined python script to test your setup of Sphinx:

python /usr/share/sphinx/api/test.py this is my test document

This command will search "this is my test document" in the example MySQL database and then show you the search result.

That concludes this tutorial. Sphinx also includes a search API, which can be used from your own PHP, Perl, Python, Ruby or Java projects. More information is available on the Sphinx official website.