Limits

To guarantee the stability and security of ApsaraDB for MySQL, certain limits are propose.

Items	Restrictions
Parameter modification	The RDS console or APIs must be used to modify database parameters. But some parameters cannot be modified. For more information, see Set parameters through RDS console.
Root permission	The root or sa permission is not provided.
Backup	Command lines or graphical interfaces can be used for logical backup. For physical backup, the RDS console or APIs must be used.
Restoration	Command lines or graphical interfaces can be used for logical restoration. For physical restoration, the RDS console or APIs must be used.
Migration	Command lines or graphical interfaces can be used for logical import. You can use the MySQL command line tool or Data Transmission Service (DTS) to migrate data.
MySQL storage engine	Currently only InnoDB and TokuDB are supported. The MyISAM engine has defects and may cause data loss. If you create MyISAM engine tables, they are automatically converted to InnoDB engine tables. For more information, see Why does RDS for MySQL not support the MyISAM engine? The InnoDB storage engine is recommended for performance and security requirements. The Memory engine is not supported. If you create Memory engine tables, they are automatically converted to InnoDB engine tables.
Replication	MySQL provides a dual-node cluster based on the master/slave replication architecture, so you manual deployment is not required. The slave instance in the architecture is invisible to you, and your application cannot access to the slave instance directly.
Restarting RDS instances	Instances must be restarted through the RDS console or APIs.
User, password, and database management	By default, RDS console is used to manage users, passwords, and databases, including operations such as instance creation, instance deletion, permission modification, and password modification. MySQL also allows you to create a master account for finer-grained management.
Common account	Does not support customized authorization. The account management and database management interfaces are provided on the RDS console. Instances that support common accounts also support master accounts.
Master account	Support customized authorization. SQL statements can be used for management.
Network settings	If a MySQL 5.5/5.6 instance is in a classic network and its access mode is safe connection mode, do not enable net.ipv4.tcp_timestamps in SNAT mode.