Review the information in Section 3.1, “Before You Begin”.

Ensure the upgrade readiness of your installation by completing the preliminary checks in Section 3.6, “Preparing Your Installation for Upgrade”.

If you use XA transactions with InnoDB, run XA RECOVER before upgrading to check for uncommitted XA transactions. If results are returned, either commit or rollback the XA transactions by issuing an XA COMMIT or XA ROLLBACK statement.

If you normally run your MySQL server configured with innodb_fast_shutdown set to 2 (cold shutdown), configure it to perform a fast or slow shutdown by executing either of these statements:

SET GLOBAL innodb_fast_shutdown = 1; -- fast shutdown
SET GLOBAL innodb_fast_shutdown = 0; -- slow shutdown

With a fast or slow shutdown, InnoDB leaves its undo logs and data files in a state that can be dealt with in case of file format differences between releases.

Shut down the old MySQL server. For example:

mysqladmin -u root -p shutdown

Upgrade the MySQL binaries or packages. If upgrading a binary installation, unpack the new MySQL binary distribution package. See Obtain and Unpack the Distribution. For package-based installations, install the new packages.

Start the MySQL 8.4 server, using the existing data directory. For example:

mysqld_safe --user=mysql --datadir=/path/to/existing-datadir &

If there are encrypted InnoDB tablespaces, use the --early-plugin-load option to load the keyring plugin.

When you start the MySQL 8.4 server, it automatically detects whether data dictionary tables are present. If not, the server creates them in the data directory, populates them with metadata, and then proceeds with its normal startup sequence. During this process, the server upgrades metadata for all database objects, including databases, tablespaces, system and user tables, views, and stored programs (stored procedures and functions, triggers, and Event Scheduler events). The server also removes files that previously were used for metadata storage. For example, after upgrading from MySQL 8.3 to MySQL 8.4, you may notice that tables no longer have .frm files.

If this step fails, the server reverts all changes to the data directory. In this case, you should remove all redo log files, start your MySQL 8.3 server on the same data directory, and fix the cause of any errors. Then perform another slow shutdown of the 8.3 server and start the MySQL 8.4 server to try again.

In the previous step, the server upgrades the data dictionary as necessary, making any changes required in the mysql system database between MySQL 8.3 and MySQL 8.4, so that you can take advantage of new privileges or capabilities. It also brings the Performance Schema, INFORMATION_SCHEMA, and sys databases up to date for MySQL 8.4, and examines all user databases for incompatibilities with the current version of MySQL.

Review the information in Section 3.1, “Before You Begin”.

Export your existing data from the previous MySQL installation:

mysqldump -u root -p
  --add-drop-table --routines --events
  --all-databases --force > data-for-upgrade.sql

Shut down the old MySQL server. For example:

mysqladmin -u root -p shutdown

Install MySQL 8.4. For installation instructions, see Chapter 2, Installing MySQL.

Initialize a new data directory, as described in Section 2.9.1, “Initializing the Data Directory”. For example:

mysqld --initialize --datadir=/path/to/8.4-datadir

Copy the temporary 'root'@'localhost' password displayed to your screen or written to your error log for later use.

Start the MySQL 8.4 server, using the new data directory. For example:

mysqld_safe --user=mysql --datadir=/path/to/8.4-datadir &

Reset the root password:

$> mysql -u root -p
Enter password: ****  <- enter temporary root password

mysql> ALTER USER USER() IDENTIFIED BY 'your new password';

Load the previously created dump file into the new MySQL server. For example:

mysql -u root -p --force < data-for-upgrade.sql

Perform any remaining upgrade operations:

Shut down the server, then restart it with the --upgrade=FORCE option to perform the remaining upgrade tasks:

mysqladmin -u root -p shutdown
mysqld_safe --user=mysql --datadir=/path/to/8.4-datadir --upgrade=FORCE &

Upon restart with --upgrade=FORCE, the server makes any changes required in the mysql system schema between MySQL 8.3 and MySQL 8.4, so that you can take advantage of new privileges or capabilities. It also brings the Performance Schema, INFORMATION_SCHEMA, and sys schema up to date for MySQL 8.4, and examines all user schemas for incompatibilities with the current version of MySQL.

Upgrade MGM nodes.

Upgrade data nodes one at a time.

Upgrade API nodes one at a time (including MySQL servers).

Import the data dictionary.

Start the new server with the --upgrade=MINIMAL option to upgrade the data dictionary but not the system tables.

The MySQL server must be connected to NDB for this phase to complete. If any NDB or NDBINFO tables exist, and the server cannot connect to the cluster, it exits with an error message:

Failed to Populate DD tables.

Upgrade the system tables by restarting each individual mysqld without the --upgrade=MINIMAL option.