way, you may want to consider building a special binary to be used on the replica that supports only the engines you want. 

•If you use raw data files (a binary backup) to set up the replica, it is not possible to change the initial table format. Instead, use ALTER TABLE  to change the table types after the replica has been started. 

•For new source/replica replication setups where there are currently no tables on the source, avoid specifying the engine type when creating new tables. 

If you are already running a replication solution and want to convert your existing tables to another engine type, follow these steps: 

1. Stop the replica from running replication updates: 

mysql> STOP SLAVE; Or from MySQL 8.0.22: mysql> STOP REPLICA; 

This makes it possible to change engine types without interruption. 

2. Execute an ALTER TABLE ... ENGINE=’ engine_type ’  for each table to be changed. 

3. Start the replication process again: 

mysql> START SLAVE; 

Or, beginning with MySQL 8.0.22: 

mysql> START REPLICA; 

Although the default_storage_engine  variable is not replicated, be aware that CREATE TABLE  and ALTER TABLE  statements that include the engine specification are replicated to the replica correctly. If, in the case of a CSV  table, you execute this statement: 

mysql> ALTER TABLE csvtable ENGINE=’MyISAM’; 

This statement is replicated; the table’s engine type on the replica is converted to InnoDB , even if you have previously changed the table type on the replica to an engine other than CSV . If you want to retain engine differences on the source and replica, you should be careful to use the default_storage_engine  variable on the source when creating a new table. For example, instead of: 

mysql> CREATE TABLE tablea (columna int) Engine=MyISAM; 

Use this format: 

mysql> SET default_storage_engine=MyISAM; mysql> CREATE TABLE tablea (columna int); 

When replicated, the default_storage_engine  variable is ignored, and the CREATE TABLE  statement executes on the replica using the replica’s default engine. 

## 17.4.5 Using Replication for Scale-Out 

You can use replication as a scale-out solution; that is, where you want to split up the load of database queries across multiple database servers, within some reasonable limitations. 

Because replication works from the distribution of one source to one or more replicas, using replication for scale-out works best in an environment where you have a high number of reads and low number of 

