What Should I Do If an ECS Cannot Connect to a GaussDB(for MySQL) Instance?

Perform the following steps to identify the problem:

1. Check whether the ECS and GaussDB(for MySQL) instance are located in the same VPC.
   • If they are in the same VPC, go to 2.
   • If they are in different VPCs, create an ECS in the VPC where the instance is located.

2. Check whether a security group has been created for the ECS.
   • If a security group has been created, check whether its rules are appropriate.
   • If no security group has been created, go to the VPC console from the ECS details page and create a security group.

3. Check whether the ECS can connect to the instance over the instance port.

   The default port of a primary/standby instance is 3306.

   telnet <IP address> {Port number}

   • If the ECS can connect to the instance, no further action is required.
   • If the ECS still cannot connect to the instance port, contact technical support.