What Should I Do If an RDS Database Problem Causes a Connection Failure?

Check whether any of the following problems occurred on the RDS DB instance.

1. The RDS DB instance is not properly connected.

   Solution: Check the connection. If you connect to the RDS DB instance through a private network, the ECS and DB instance must be in the same VPC and the DB instance can be accessed only through an ECS in the same VPC. If you connect to the RDS DB instance through a public network, the ECS and DB instance can be in different VPCs.

2. The maximum number of connections has been reached.

   Solution: Use RDS resource monitoring to check if the CPU usage and the number of current connections are abnormal. If either of them has reached the maximum, reboot, disconnect, or scale up the class of the RDS DB instance.

3. The DB instance is abnormal. For example, the RDS DB instance fails to be rebooted, the system is faulty, or the instance or table is locked.

   Solution: Reboot the RDS DB instance to see if the problem is resolved. If the problem persists, contact post-sales technical support.