Upgrading MySQL from 5.7 to 8.0

Upgrading MySQL from 5.7 to 8.0 was mostly uneventful.

Here are the steps I did.

1. Stop the running 5.7 instance.
2. Make ZFS snapshots of these three filesystems:
   1. zfs snap enterprise_zdata/var/db/mysql@pre-8.0
   2. zfs snap enterprise_zdata/var/db/mysql_secure@pre-8.0
   3. zfs snap enterprise_zdata/var/db/mysql_tmpdir@pre-8.0
3. Upgrade to 8.0.
4. Review the new my.cnf.sample in /usr/local/etc/mysql. In my case, my my.cnf differs from the stock version in a couple of areas. See below.
5. Start the 8.0 instance. Remember, the server will now automatically run the steps previously done using mysql_upgrade. This first start will be significantly slower than the subsequent ones.
6. I noticed “mysqlx” defaults to listening on [::] and on TCP port 33060, which may be undesired. I adjusted my.cnf accordingly and restarted MySQL.

--- /usr/local/etc/mysql/my.cnf.sample  2023-03-13 13:26:55.000000000 +0100
+++ /usr/local/etc/mysql/my.cnf 2023-03-13 14:29:50.000000000 +0100
@@ -11,6 +14,8 @@
 port                            = 3306
 socket                          = /tmp/mysql.sock
 bind-address                    = 127.0.0.1
+mysqlx-port                     = 33060
+mysqlx-bind-address             = 127.0.0.1
 basedir                         = /usr/local
 datadir                         = /var/db/mysql
 tmpdir                          = /var/db/mysql_tmpdir
@@ -50,6 +55,7 @@
 innodb_write_io_threads         = 8
 innodb_read_io_threads          = 8
 innodb_autoinc_lock_mode        = 2
+innodb_file_per_table           = ON

 [mysqldump]
 max_allowed_packet              = 256M