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:When you connect to an RDS Database, an error message related to max_user_connections is displayed

Last Updated:May 11, 2022


When you connect to an RDS database through the DMS console or a database client, the error message "max_user_connections" is displayed.


The number of connections to the RDS Database is full, causing the failure to connect properly.


Alibaba Cloud reminds you that:

  • Before you perform operations that may cause risks, such as modifying instance configurations or data, we recommend that you check the disaster recovery and fault tolerance capabilities of the instances to ensure data security.
  • You can modify the configurations and data of instances including but not limited to Elastic Compute Service (ECS) and Relational Database Service (RDS) instances. Before the modification, we recommend that you create snapshots or enable RDS log backup.
  • If you have authorized or submitted security information such as the logon account and password in the Alibaba Cloud Management Console, we recommend that you modify such information in a timely manner.

When this problem occurs, you must disconnect actively to prevent the connection from being released, which keeps occupying a full number of connections:

  • The connection can be released by restarting the database in the RDS console.
  • If you cannot restart the instance in the console, you must wait a period of time until the RDS connection is gradually released before logging on.
  • If you can log on to the database or need to optimize the problem of full connections, see how to deal with full connections of apsaradb RDS for MySQL.

Application scope

  • Apsaradb RDS for MySQL