MySQL is the most popular relational database management system (RDBMS) used for managing the majority of the web and enterprise applications. But technology continues to evolve day by day, and therefore newer versions of MySQL upgrade are coming out with improved performance, security patches, bug fixes, and new features. MySQL must be upgraded to provide database stability, security, and optimality.
This handbook will take you through all you’d want to know when upgrading MySQL, including why you should upgrade, how to get ready for an upgrade, step-by-step guidelines on upgrading, debugging usual problems, and guidelines for a smooth upgrade.
Why Upgrade MySQL?
Upgrading MySQL provides several benefits:
1. Performance Improvements
- Newer MySQL upgrade versions come with better indexing, query optimization, and storage engine improvements.
- MySQL 8.0 introduces better JSON handling, indexing, and caching mechanisms.
2. Security Enhancements
- Older versions may have vulnerabilities that can be exploited.
- MySQL upgrade 8.0 enhances authentication with caching_sha2_password, making databases more secure.
3. Compatibility with New Technologies
- Many modern web applications and frameworks rely on the latest MySQL features.
- Deprecated features in older versions can cause compatibility issues with new software.
4. Improved Query Execution
- MySQL 8.0 has improved query performance with better indexing, hash joins, and query optimizations.
5. Long-Term Support
- MySQL 5.7 reached end-of-life (EOL) in October 2023, meaning it no longer receives updates or security patches.
- MySQL 8.0 is the latest stable release and receives active support.
Key Considerations Before Upgrading
Before MySQL upgrade, you should:
1. Backup Your Database
- Always create a full backup of your MySQL data before upgrading.
- Use
mysqldumpor MySQL’s native backup tools to ensure data safety.
2. Check Version Compatibility
- MySQL 8.0 introduces significant changes that may break compatibility with older databases.
- Check for deprecated features, authentication changes, and data type modifications.
3. Review Application Dependencies
- Ensure that your applications, frameworks, and plugins support MySQL 8.0.
- If your application is not compatible, consider updating it before upgrading MySQL.
4. Test the Upgrade in a Staging Environment
- Do not upgrade directly on a production server.
- Test the upgrade on a development or staging environment to identify potential issues.
5. Review Configuration Changes
- Some MySQL configuration settings (
my.cnformy.ini) have changed between versions. - Review MySQL 8.0 release notes to update your settings accordingly.
How to Upgrade MySQL 5.7 to 8.0
Step 1: Check Your Current MySQL Version
To check your MySQL upgrade version, run:
mysql --version
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This will return something like:
If your version is 5.7, you can proceed with the upgrade.
Step 2: Backup Your MySQL Databases
Before upgrading, create a backup of all databases using mysqldump:
mysqldump --all-databases --add-drop-database --single-transaction --quick --lock-tables=false > backup.sql
For more safety, also back up the MySQL configuration files:
cp /etc/mysql/my.cnf /etc/mysql/my.cnf.backup
Step 3: Stop MySQL Service
On Linux, stop the MySQL service before upgrading:
sudo systemctl stop mysql
On Windows, stop the MySQL service using:
net stop mysql
Step 4: Uninstall MySQL 5.7
On Ubuntu/Debian, remove the existing MySQL 5.7 packages:
sudo apt-get remove --purge mysql-server mysql-client mysql-common mysql-server-core-* mysql-client-core-*
sudo apt-get autoremove
sudo apt-get autoclean
On CentOS/RHEL, use:
sudo yum remove mysql mysql-server
On Windows, use the Control Panel to uninstall MySQL Server.
Step 5: Install MySQL 8.0
On Ubuntu/Debian, run:
wget https://dev.mysql.com/get/mysql-apt-config_0.8.22-1_all.deb
sudo dpkg -i mysql-apt-config_0.8.22-1_all.deb
sudo apt update
sudo apt install mysql-server
On CentOS/RHEL, use:
sudo yum install https://dev.mysql.com/get/mysql80-community-release-el7-5.noarch.rpm
sudo yum install mysql-community-server
On Windows, download the MySQL 8.0 installer from the MySQL website and follow the installation steps.
Step 6: Start MySQL Service
After installation, restart the MySQL service:
sudo systemctl start mysql
sudo systemctl enable mysql
Check if MySQL is running correctly:
mysqladmin -u root -p version
Step 7: Run MySQL Upgrade Tool
After upgrading MySQL, run the mysql_upgrade command to update system tables:
mysql_upgrade -u root -p
If using MySQL 8.0.16 or later, mysql_upgrade runs automatically when you start MySQL.
Step 8: Verify the Upgrade
To confirm the upgrade, check the MySQL version again:
mysql --version
It should now show something like:
Also, check if your databases are accessible and running properly.
Common Issues and Troubleshooting
1. Authentication Plugin Issues
MySQL 8.0 uses caching_sha2_password by default instead of mysql_native_password. If your application does not support this, you may need to revert it:
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'your_password';
FLUSH PRIVILEGES;
2. Incompatible SQL Modes
Some default SQL modes have changed. If your application has issues, try modifying SQL modes:
SET GLOBAL sql_mode='STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION';
3. Table Structure Changes
MySQL 8.0 no longer supports some old storage formats. Run:
mysqlcheck --all-databases --check-upgrade --auto-repair -u root -p
Conclusion
Upgrading MySQL from 5.7 to 8.0 is essential for better security, performance, and compatibility. However, it requires careful planning, testing, and execution to prevent issues.
Key Takeaways:
- Always backup your data before upgrading.
- Test the upgrade in a staging environment before applying it to production.
- Use
mysql_upgradeto ensure compatibility. - Review authentication changes, SQL modes, and deprecated features.
By following this guide, you can successfully upgrade MySQL and ensure a smooth transition.
FAQs
1. Why would I upgrade MySQL?
Upgrading MySQL is necessary to enhance security, performance, and compatibility with new applications. New versions bring better indexing, query optimization, and authentication mechanisms that ensure improved efficiency and protection against threats.
2. What are the risks of upgrading MySQL?
The primary threats are application compatibility, obsolete functionality, and the risk of data corruption if not performed correctly. In order to avoid risks, always backup your database and pre-test the upgrade on a staging environment prior to installing it to production.
3. Can I directly upgrade MySQL from 5.7 to 8.0?
Yes, but it must be done with proper preparation. Upgrades directly from MySQL 5.7 to 8.0 are supported, but missing a major version (e.g., 5.6 to 8.0) is not advisable. Use the mysql_upgrade tool to configure system tables and settings.
4. What is mysql_upgrade, and should I run it?
mysql_upgrade is a utility that upgrades system tables and verifies compatibility problems following a MySQL upgrade. It makes sure database structures are modified to conform to the new version.
