This topic provides the notes that you must understand before you use the proxy terminals provided by ApsaraDB RDS for MySQL.
- When you change the specifications of the primary RDS instance or read-only RDS instances, you may experience a transient connection.
- After a read-only RDS instance is created, only the requests over a new connection can be routed to the new read-only RDS instance.
- Proxy instances, read-only RDS instances, and primary RDS instances are separately billed.
- Dedicated proxy endpoints do not support compression protocols.
- If a dedicated proxy endpoint is used to connect to your database system, all requests that are encapsulated in transactions are routed to the primary RDS instance.
- If a dedicated proxy endpoint is used to implement read/write splitting, the read consistency of the requests that are not encapsulated in transactions cannot be ensured. If you require read consistency for these requests, you can encapsulate these requests in transactions.
- If a dedicated proxy endpoint is used to connect to your database system, the
SHOW PROCESSLISTstatement returns a result set for each query. The result set consists of the query results from the primary RDS instance and read-only RDS instances.
- The connection pool feature is enabled by default. Therefore, the
SHOW PROCESSLISTstatement may return idle connections. For more information, see Set the connection pool type of an ApsaraDB RDS for MySQL instance.
- If you run multi-statement queries or stored procedures, the read/write splitting feature is disabled. In this case, all the subsequent requests over the current connection are routed to the primary RDS instance. To enable the read/write splitting feature again, you must close the current connection and establish a new connection. For more information about multi-statement queries, see Multi-Statement.
- If you use the MySQL CLI to establish a connection and execute hints, you must add the
-cparameter to these hints. If you do not add this parameter to a hint, the MySQL CLI filters the hint out. For more information about the syntax of hints, see Execute hints on an ApsaraDB RDS for MySQL instance.