MySQL Upgrade from 8.0.4 to 8.4.x (RHEL) Internet

This article describes the steps, checks, and dependencies required to upgrade MySQL from version 8.0.4 to 8.4.x on RHEL 8 systems. It covers prerequisites, pre-upgrade tasks, upgrade execution, post-upgrade validations, and rollback procedures to ensure a safe and reliable production upgrade.

Prerequisites

OS Compatibility

• Verify that the operating system supports MySQL 8.4.

• Recommended: RHEL 8.x or later.

• Check the OS version:

  cat /etc/os-release

System Requirements

• Ensure sufficient disk space for backup and rollback (df -Th).

• Confirm root or sudo access.

• All listed commands must be executed.

Pre-Upgrade Checks

Backup

• Perform a logical backup of the MySQL database.

• Log Management Procedure

• Confirm you are backing up the correct schema.

  mkdir /home/ec2-user/mysql_backup  
  mysqldump -u root -p ovaledgedb > /home/ec2-user/mysql_backup/ovaledgedb_backup.sql

  

Ensure sufficient space is available before running the mysqldump command.

• Back up configuration files:

  sudo cp /etc/my.cnf /home/ec2-user/mysql_backup/  
  sudo cp -a /var/lib/mysql /home/ec2-user/mysql_backup/

  

Database Size and Row Count Check

• Run the following queries before upgrading:

  Database size query:

  SELECT 
      table_schema AS "Database Name", 
      ROUND(SUM(data_length + index_length) / 1024 / 1024, 1) AS "DB Size (MB)"
  FROM information_schema.tables 
  GROUP BY table_schema;

  

  Row count query: (Download SQL script)

  
• Save outputs for post-upgrade comparison.

Upgrade Execution

Stop MySQL Services

Stop MySQL services by running the following command

mysql --version  
sudo systemctl stop mysqld

Install MySQL 8.4.x

• Download repository package:

  wget https://dev.mysql.com/get/mysql84-community-release-el8-1.noarch.rpm

  
• Install repository:

  sudo yum localinstall mysql84-community-release-el8-1.noarch.rpm

  
• Disable any existing MySQL 8.0 repositories:

  sudo vi /etc/yum.repos.d/mysql-community.repo
  # enable=0 (disable) / enable=1 (enabled)

• Disable MySQL module in the package manager:

  sudo yum module disable mysql -y

  
• Install MySQL 8.4.x:

  sudo yum install mysql-community-server

  
• Check installed version:

  mysql --version

  

Update Configuration

• Edit the configuration file:

  sudo vi /etc/my.cnf
  mysql_native_password=ON

• Save file and restart MySQL:

  sudo systemctl restart mysqld  
  sudo systemctl status mysqld

  
• Verify upgrade by checking MySQL version.

  

Post-Upgrade Validations

Verify Row Counts and Database Size

• Connect to MySQL:

  mysql -u root -p

• Run validation queries:

  • Row count query: SQL Script

    
  • Database size query:

    SELECT 
        table_schema AS "Database Name", 
        ROUND(SUM(data_length + index_length) / 1024 / 1024, 1) AS "DB Size (MB)"
    FROM information_schema.tables 
    GROUP BY table_schema;

    
• Compare results with pre-upgrade outputs.

Update MySQL Parameters

• Add/update parameters in /etc/my.cnf:

  max_binlog_size=1GB
  binlog_expire_logs_seconds=2592000
  group_concat_max_len=50000
  max_connections=600
  innodb_buffer_pool_size=10GB
  max_allowed_packet=1G
  bind-address=0.0.0.0

• Adjust values as per client instance size.

  
• Restart MySQL:

  sudo systemctl restart mysqld

  

Update Application User Passwords (Optional)

• Change OvalEdge MySQL user passwords:

  ALTER USER 'ovaledge'@'localhost' IDENTIFIED BY '<Password>';  
  ALTER USER 'ovaledge'@'%' IDENTIFIED BY '<Password>';  
  FLUSH PRIVILEGES;

At this stage, the MySQL database has been upgraded to version 8.4 and the default OvalEdge MySQL password has been changed.

Rollback Plan (if required)

• Take backup of MySQL 8.4 installation before rollback:

  mkdir /home/ec2-user/mysql8.4_backup  
  sudo cp /etc/my.cnf /home/ec2-user/mysql8.4_backup  
  sudo cp -a /var/lib/mysql /home/ec2-user/mysql8.4_backup

• Stop MySQL services, reinstall MySQL 8.0.4, start the service, and restore data from backups.

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