Upgrading a Replication Setup replicas. Alternatively, if you cannot stop new statements, temporarily change to row-based logging on the source ( binlog_format=ROW ) and wait until all replicas have processed all binary logs produced up to the point of this change, then upgrade the replicas. The default character set has changed from  latin1  to  utf8mb4  in MySQL 8.0. In a replicated setting, when upgrading from MySQL 5.7 to 8.0, it is advisable to change the default character set back to the character set used in MySQL 5.7 before upgrading. After the upgrade is completed, the default character set can be changed to  utf8mb4 . Assuming that the previous defaults were used, one way to preserve them is to start the server with these lines in the  my.cnf  file: After the replicas have been upgraded, shut down the source, upgrade it to the same 8.0.x release as the replicas, and restart it. If you had temporarily changed the source to row-based logging, change it back to statement-based logging. The 8.0 source is able to read the old binary logs written prior to the upgrade and to send them to the 8.0 replicas. The replicas recognize the old format and handle it properly. Binary logs created by the source subsequent to the upgrade are in 8.0 format. These too are recognized by the 8.0 replicas. In other words, when upgrading to MySQL 8.0, the replicas must be MySQL 8.0 before you can upgrade the source to 8.0. Note that downgrading from 8.0 to older versions does not work so simply: You must ensure that any 8.0 binary log or relay log has been fully processed, so that you can remove it before proceeding with the downgrade. Some upgrades may require that you drop and re-create database objects when you move from one MySQL series to the next. For example, collation changes might require that table indexes be rebuilt. Such operations, if necessary, are detailed at Section 2.11.4, “Changes in MySQL 8.0” . It is safest to perform these operations separately on the replicas and the source, and to disable replication of these operations from the source to the replica. To achieve this, use the following procedure: If you are upgrading an existing replication setup from a version of MySQL that does not support global transaction identifiers to a version that does, you should not enable GTIDs on either the source or the replica before making sure that the setup meets all the requirements for GTID-based replication. See 3683 5. Restart the replicas, this time without the  --skip-slave-start  option or  skip_slave_start system variable. 4. Re-enable the binary log on the source. If you set  sql_log_bin  to  OFF  earlier, execute a  SET sql_log_bin = ON  statement. If you restarted the source to disable the binary log, restart it without --skip-log-bin , and without enabling the  skip_networking  system variable so that clients and replicas can connect. 3. With the binary log disabled, perform any table repair or rebuilding operations needed to re-create database objects. The binary log must be disabled during this step to prevent these operations from being logged and sent to the replicas later. 2. Disable the binary log on the source. To do this without restarting the source, execute a  SET sql_log_bin = OFF  statement. Alternatively, stop the source and restart it with the  --skip-log- bin  option. If you restart the source, you might also want to disallow client connections. For example, if all clients connect using TCP/IP, enable the  skip_networking  system variable when you restart the source. 1. Stop all the replicas and upgrade them. Restart them with the  --skip-slave-start  option, or from MySQL 8.0.24, the  skip_slave_start  system variable, so that they do not connect to the source. Perform any table repair or rebuilding operations needed to re-create database objects, such as use of REPAIR TABLE  or  ALTER TABLE , or dumping and reloading tables or triggers. [mysqld] character_set_server=latin1 collation_server=latin1_swedish_ci