Upgrading MySQL from version 5.6 to 5.7 on a CentOS 7 server is essential to ensure continued support, improved performance, security updates, and access to new features. MySQL 5.7 brings enhancements in query performance, replication, security, JSON support, and optimizer improvements.

Before starting the upgrade, back up all critical databases and configuration files, as the upgrade process may involve changes that are not reversible.

This guide walks you through the step-by-step process to upgrade MySQL 5.6 to 5.7 safely on a CentOS 7 server installed using the server OS images provided by the Kamatera cloud platform.

Step-by-step guide

1. For this guide, we are using CentOS 7, installed via Kamatera’s Server OS images. In the Kamatera management console, select the server, click on CONNECT in the middle pane, and then choose Open Remote Console as shown in the screen below. 

2.  Once the remote console is open, log in using your username and password.

3. Now, connect to the server via SSH using the root user and password:

Command:

ssh root@<your-server-ip>

Note: Replace <your-server-ip> with the actual public IP address of your Kamatera server.
When prompted with: “Are you sure you want to continue connecting (yes/no)? Type yes and press Enter.

Then, when prompted, enter the root password to complete the login.

4. Confirm your current MySQL version: 

Command:

mysql –V

Note: It should show something like: mysql Ver 14.14 Distrib 5.6.51.

5. Now, check whether  mysqldump tool (which is part of MySQL client utilities) is installed on your CentOS 7 server. If it is not installed, you can install the MySQL Client tools using the MySQL yum repository.

Command:

sudo yum install mysql -y

Note: This package includes mysql, mysqldump, and other essential client tools.

6. Before making any changes, back up your existing databases and MySQL configuration. 

• Backup all databases: 

To do that, use mysqldump to create a full backup of all MySQL databases

Command:

mysqldump -u root -p --all-databases > /root/all-databases-backup.sql 

• This will prompt you for your MySQL root password. Enter the password.
• It creates a file /root/all-databases-backup.sql containing all your databases.

• Backup MySQL configuration file:

Run the command below to make a copy of the current MySQL configuration in case you need to restore it.

       Command:

 cp /etc/my.cnf  /etc/my.cnf.bak

Note: You may also take a snapshot if you’re using Kamatera’s cloud server snapshot feature. 

7. Remove MySQL 5.6 and related server/client packages: 

Use the command below, if you already installed MySQL 5.6 and want to upgrade cleanly to 5.7. 

Command:

yum remove mysql mysql-server mysql-libs mysql-community-server

Note: This removes the actual MySQL 5.6 components (binaries, libraries, and running server).

8. Remove the MySQL 5.6 YUM repository config:

Use this if you added the MySQL 5.6 YUM repo earlier, so you can replace it with the 5.7 repo.

Command:

sudo yum remove mysql-community-release

Note: This removes the repository configuration, which helps prevent conflicts when you later add the MySQL 5.7 repo.

9. Now, download and add the official MySQL 5.7 repository from Oracle: 

Command:

wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

10. Once downloaded, install the RPM. 

Command:

sudo rpm -ivh mysql57-community-release-el7-11.noarch.rpm

Note: You should see messages like Preparing… and Installing… if it’s successful.

(An .rpm file is like a .exe installer on Windows or .deb on Debian-based Linux.
It contains precompiled software, configuration files, and metadata to install a program cleanly).

11. Proceed to Install MySQL 5.7 

Command:

 sudo yum install mysql-community-server 

When prompted “Is this ok [y/d/N]”.  Type y and press Enter.

12. Ensure that only MySQL 5.7 is enabled by running the below commands: 

Command:

sudo yum-config-manager --disable mysql80-community

Command:

sudo yum-config-manager --enable mysql57-community

13. Now upgrade the MySQL server package:

Command:

sudo yum update mysql-server

14. Ensure the MySQL service is running and enabled on boot: 

Command:

sudo systemctl start mysqld

Command:

sudo systemctl enable mysqld

15. This command is used to check and upgrade the MySQL system tables after a MySQL version upgrade (for example, from 5.6 to 5.7 or 5.7 to 8.0).                                         

Command:

mysql_upgrade -u root -p

16. Once the upgrade script is complete, restart the service by running the below command.

Command:

sudo systemctl restart mysqld

17. Now, check that the new version is installed:

Command:

mysql -V

Note: It should show something like: mysql Ver 14.14 Distrib 5.7.44.

18. Check for any post-upgrade warnings or errors:

Command:

sudo tail -n 100 /var/log/mysqld.log

19. Verify that your applications and databases are functioning correctly after the upgrade. 

• Check MySQL Server Status:

Command:

sudo service mysqld status

Note: Should say: active (running)

• Log In to MySQL

Command:

mysql -u root –p

When prompted, enter the password.

Now, run the queries:

SHOW DATABASES;

SELECT VERSION(); 

Note: This confirms access and upgraded version.

By carefully following the steps outlined in this guide, you can successfully upgrade MySQL from 5.6 to 5.7 on your CentOS 7 server while minimizing downtime and ensuring data integrity, keeping your environment secure and up to date.