MySQL Router 8.4 Release Notes
        The default value of --server-ssl-mode is
        changed from AS_CLIENT to
        PREFERRED.
       (WL #15966)
MySQL Router now supports client TLS certificates.
The following configuration options are introduced:
            server_ssl_key
          
            server_ssl_cert
          
            client_ssl_ca
          
            client_ssl_capath
          
            client_ssl_crl
          
            client_ssl_crlpath
          
            router_require_enforce
          
(WL #14304)
        If a client sent read-only statements to a destination which was
        not configured as super_read_only, using the
        Read-Write splitting port, MySQL Router redirected the statement to
        the primary. The statement did not return the correct result.
       (Bug #36042078)
Queries with trailing semi-colons (;) were treated as multi-statements, which is not permitted if MySQL Router is configured for Read-Write Splitting. (Bug #36036725)
It was not possible to connect to the read-write splitting port with Connector/J. The following error was returned:
       Unknown character set ''
      (Bug #35968017)
If MySQL Router was bootstrapped over an existing configuration, the existing user's credentials were retrieved from the keyring and reused, even if the user used the deprecated authentication plugin, mysql_native_password.
        As of this release, MySQL Router checks the user's authentication
        method and, if it is set to mysql_native_password, changes it to
        the Cluster's default if there are no other
        user@host entries for the MySQL Router user. If
        there is more than one such entry, a warning is returned,
        advising the user to manually correct the authentication
        configuration.
       (Bug #35943415)
        If MySQL Router was bootstrapped against an InnoDB Cluster,
        without using an existing account or using the
        --force-password-verification parameter, the
        auto-created metadata user was created using the
        mysql_native_password plugin. This plugin was
        deprecated in MySQL Server 8.1 and is subject to removal in a
        future release.
      
As of this release, the metadata user is created using the default authorization plugin defined on the InnoDB Cluster. (Bug #35737357)
In the Docker image for MySQL Router 8.2.0, the read-write splitting port, 6450, was not exposed by default. (Bug #112900, Bug #35964936)