As of MySQL 8.0.16, the MySQL server performs the upgrade tasks previously handled by mysql_upgrade (for details, see Section 2.10.3, “What the MySQL Upgrade Process Upgrades”). Consequently, mysql_upgrade is unneeded and is deprecated as of that version; expect it to be removed in a future version of MySQL. Because mysql_upgrade no longer performs upgrade tasks, it exits with status 0 unconditionally.

You should always back up your current MySQL installation before performing an upgrade. See Section 7.2, “Database Backup Methods”.

Some upgrade incompatibilities may require special handling before upgrading your MySQL installation and running mysql_upgrade. See Section 2.10, “Upgrading MySQL”, for instructions on determining whether any such incompatibilities apply to your installation and how to handle them.

mysql_upgrade --protocol=tcp -P 3306 [other_options]
mysql_upgrade --protocol=tcp -P 3307 [other_options]
mysql_upgrade --protocol=tcp -P 3308 [other_options]

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

mysql> ALTER USER USER() IDENTIFIED BY 'root-password';

$> mysql_upgrade [options]

If you run the server with the disabled_storage_engines system variable set to disable certain storage engines (for example, MyISAM), mysql_upgrade might fail with an error like this:

mysql_upgrade: [ERROR] 3161: Storage engine MyISAM is disabled
(Table creation is disallowed).

To handle this, restart the server with disabled_storage_engines disabled. Then you should be able to run mysql_upgrade successfully. After that, restart the server with disabled_storage_engines set to its original value.

The mysql_upgrade_info file is deprecated; expect it to be removed in a future version of MySQL.

A sys schema exists with no sys.version view. If
you have a user created sys schema, this must be renamed for the
upgrade to succeed.

Display a short help message and exit.

On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.

The directory where character sets are installed. See Section 10.15, “Character Set Configuration”.

Compress all information sent between the client and the server if possible. See Section 4.2.8, “Connection Compression Control”.

As of MySQL 8.0.18, this option is deprecated. Expect it to be removed in a future version of MySQL. See the section called “Configuring Legacy Connection Compression”.

The permitted compression algorithms for connections to the server. The available algorithms are the same as for the protocol_compression_algorithms system variable. The default value is uncompressed.

For more information, see Section 4.2.8, “Connection Compression Control”.

This option was added in MySQL 8.0.18.

Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:O,/tmp/mysql_upgrade.trace.

Print some debugging information when the program exits.

Print debugging information and memory and CPU usage statistics when the program exits.

A hint about which client-side authentication plugin to use. See Section 6.2.17, “Pluggable Authentication”.

Use charset_name as the default character set. See Section 10.15, “Character Set Configuration”.

Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory.

For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.

Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory.

For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.

Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysql_upgrade normally reads the [client] and [mysql_upgrade] groups. If this option is given as --defaults-group-suffix=_other, mysql_upgrade also reads the [client_other] and [mysql_upgrade_other] groups.

For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.

Ignore the mysql_upgrade_info file and force execution even if mysql_upgrade has already been executed for the current version of MySQL.

Request from the server the public key required for RSA key pair-based password exchange. This option applies to clients that authenticate with the caching_sha2_password authentication plugin. For that plugin, the server does not send the public key unless requested. This option is ignored for accounts that do not authenticate with that plugin. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.

If --server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over --get-server-public-key.

For information about the caching_sha2_password plugin, see Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”.

Connect to the MySQL server on the given host.

Read options from the named login path in the .mylogin.cnf login path file. A “login path” is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use the mysql_config_editor utility. See mysql_config_editor(1).

For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.

The maximum size of the buffer for client/server communication. The default value is 24MB. The minimum and maximum values are 4KB and 2GB.

The initial size of the buffer for client/server communication. The default value is 1MB − 1KB. The minimum and maximum values are 4KB and 16MB.

Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read.

The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when --no-defaults is used. To create .mylogin.cnf, use the mysql_config_editor utility. See mysql_config_editor(1).

For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.

The password of the MySQL account used for connecting to the server. The password value is optional. If not given, mysql_upgrade prompts for one. If given, there must be no space between --password= or -p and the password following it. If no password option is specified, the default is to send no password.

Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 6.1.2.1, “End-User Guidelines for Password Security”.

To explicitly specify that there is no password and that mysql_upgrade should not prompt for one, use the --skip-password option.

On Windows, connect to the server using a named pipe. This option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable.

The directory in which to look for plugins. Specify this option if the --default-auth option is used to specify an authentication plugin but mysql_upgrade does not find it. See Section 6.2.17, “Pluggable Authentication”.

For TCP/IP connections, the port number to use.

Print the program name and all options that it gets from option files.

The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, see Section 4.2.7, “Connection Transport Protocols”.

The path name to a file in PEM format containing a client-side copy of the public key required by the server for RSA key pair-based password exchange. This option applies to clients that authenticate with the sha256_password or caching_sha2_password authentication plugin. This option is ignored for accounts that do not authenticate with one of those plugins. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.

If --server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over --get-server-public-key.

For sha256_password, this option applies only if MySQL was built using OpenSSL.

For information about the sha256_password and caching_sha2_password plugins, see Section 6.4.1.3, “SHA-256 Pluggable Authentication”, and Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”.

On Windows, the shared-memory name to use for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case-sensitive.

This option applies only if the server was started with the shared_memory system variable enabled to support shared-memory connections.

By default, mysql_upgrade installs the sys schema if it is not installed, and upgrades it to the current version otherwise. The --skip-sys-schema option suppresses this behavior.

For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.

On Windows, this option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable.

Controls whether to enable FIPS mode on the client side. The --ssl-fips-mode option differs from other --ssl-xxx options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 6.8, “FIPS Support”.

These --ssl-fips-mode values are permitted:

The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.

This option was added in MySQL 8.0.16.

The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.

Upgrade only the system tables in the mysql schema, do not upgrade user schemas.

The user name of the MySQL account to use for connecting to the server. The default user name is root.

Verbose mode. Print more information about what the program does.

Check the version of the server to which mysql_upgrade is connecting to verify that it is the same as the version for which mysql_upgrade was built. If not, mysql_upgrade exits. This option is enabled by default; to disable the check, use --skip-version-check.

By default, binary logging by mysql_upgrade is disabled. Invoke the program with --write-binlog if you want its actions to be written to the binary log.

When the server is running with global transaction identifiers (GTIDs) enabled (gtid_mode=ON), do not enable binary logging by mysql_upgrade.

The compression level to use for connections to the server that use the zstd compression algorithm. The permitted levels are from 1 to 22, with larger values indicating increasing levels of compression. The default zstd compression level is 3. The compression level setting has no effect on connections that do not use zstd compression.

For more information, see Section 4.2.8, “Connection Compression Control”.

This option was added in MySQL 8.0.18.