How to Upgrade MySQL 5.6 to 5.7

MySQL, a widely-used open-source relational database management system, has been a pillar of web development since its launch in 1995. Known for its reliability and flexibility, MySQL supports numerous storage engines and powers leading applications such as Facebook and WordPress. To ensure that your MySQL database remains secure, optimized, and up-to-date with the latest features, upgrading your MySQL version is essential. This guide will walk you through upgrading from MySQL 5.6 to MySQL 5.7, covering preparation, execution, and post-upgrade steps. We’ll also include tips on downgrading if needed.

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Why Upgrade MySQL?

Upgrading MySQL brings several benefits:

• Enhanced Performance and Stability: Each new version offers optimizations and performance improvements that enhance the overall speed and efficiency of your database.
• Security Updates: New versions include critical security patches, protecting your database from vulnerabilities.
• New Features: Upgrading ensures access to new features that can improve development and administration.

With these advantages in mind, let’s dive into the upgrade process from MySQL 5.6 to 5.7.

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Preparation Steps

Before starting the upgrade, it’s crucial to prepare to minimize downtime and ensure a smooth process. Here’s how to get ready:

1. Backup Your Data
   Start by taking a full backup of your database to prevent data loss. Use tools like mysqldump or mysqlhotcopy to create a complete backup of all databases:

   
   mysqldump -u root -p --all-databases > all_databases_backup.sql
   

   This backup will be useful if you need to restore your data.

2. Check Application Compatibility
   Verify that your applications are compatible with MySQL 5.7. Check for any deprecated features or behavior changes that may affect functionality. MySQL’s release notes and documentation provide insights into these changes.

3. Review MySQL Documentation
   Familiarize yourself with MySQL’s upgrade documentation for a comprehensive understanding of changes and improvements. This will help you anticipate any differences in behavior after the upgrade.

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Step-by-Step Upgrade Process

Below is a detailed, step-by-step guide to upgrade from MySQL 5.6 to MySQL 5.7.

1. Stop MySQL 5.6
   Ensure that your MySQL 5.6 server is not running before beginning the upgrade process.

   
   sudo service mysqld stop
   

2. Remove Existing MySQL 5.6 Installation
   Cleanly remove the MySQL 5.6 installation to avoid conflicts with the new version.

   
   sudo yum remove mysql-community-server-5.6.37–2.el6.x86_64
   sudo yum remove mysql-community-server
   

3. Clean Yum Cache
   Clearing the Yum cache removes any cached data that could interfere with the new installation.

   
   sudo yum clean all
   

4. Backup and Remove my.cnf
   Backup your existing configuration file to keep a record of any custom settings. Removing this file allows the new MySQL version to create a fresh configuration.

   
   cp /etc/my.cnf /etc/my.cnf.bak
   rm /etc/my.cnf
   

5. Install MySQL 5.7
   Install MySQL 5.7 using the following command. This may take a few minutes:

   
   sudo yum install mysql57-server.x86_64
   

6. Start MySQL 5.7 and Perform Initial Recovery
   Start the MySQL 5.7 server, which may require a recovery process depending on your data size:

   
   sudo service mysqld start
   

7. Connect to MySQL
   Test the connection to your MySQL server to verify that the installation is working correctly.

   
   mysql -u root -p
   

8. Stop MySQL Server
   Temporarily stop the MySQL server for additional maintenance.

   
   sudo service mysqld stop
   

9. Start MySQL with Skip-Grant-Tables
   This step can be necessary for certain maintenance tasks and will allow MySQL to start without loading the privilege tables.

   
   sudo mysqld --skip-grant-tables --user=root &
   

10. Run MySQL Upgrade Command
    Run the upgrade command to apply updates to system tables and data directories. Use either:

sudo mysql_upgrade57

or

sudo mysql_upgrade

11. Stop the mysqld Process
    Stop the MySQL server that was started with --skip-grant-tables.

sudo killall mysqld

12. Adjust File Permissions
    Ensure MySQL has the appropriate permissions for its directories.

sudo chown -R mysql:mysql /var/lib/mysql/

13. Restart MySQL 5.7
    Finally, restart MySQL 5.7 to ensure all changes are applied.

sudo service mysqld start

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Post-Upgrade Validation

After upgrading, it’s essential to validate that everything is working correctly:

• Check Logs: Review the MySQL error logs to identify any potential issues.
• Test Applications: Run critical applications to ensure there are no issues with compatibility or functionality.
• Monitor Performance: Observe performance metrics to confirm that the upgrade has positively impacted performance.

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Downgrading MySQL from 5.7 to 5.6

If you encounter issues with MySQL 5.7 and need to revert to 5.6, follow these steps carefully:

1. Backup All Databases: Before downgrading, back up all databases to avoid data loss.
2. Remove MySQL 5.7

   
   sudo yum remove mysql57-server.x86_64
   

3. Clean Yum Cache Again

   
   sudo yum clean all
   

4. Reinstall MySQL 5.6

   
   sudo yum install mysql-community-server-5.6.x86_64
   

5. Restore Backup: Use the backup created earlier to restore your databases.

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Conclusion

Upgrading MySQL is a crucial step in maintaining a secure and efficient database environment. By following this guide, you can smoothly transition from MySQL 5.6 to 5.7. Always remember to back up data, test compatibility, and review documentation to minimize downtime and ensure a successful upgrade.