What Should I Do If an ECS Cannot Connect to a DDS DB Instance?

Ravger · Created May 4, 2017 05:54:31

Perform the following steps to identify the problem:

Check whether the ECS and DDS DB 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 DDS DB instance is located.
Check whether a security group has been added for the ECS.
- If a security group has been added, check whether its configuration rules are suitable. For details, see the description of a security group in Purchasing a DB Instance.
- If no security group has been added, go to the VPC page from the ECS console and click Security Groups to add a security group.
On the ECS, check whether the DDS DB instance address port can be connected. The default mongos port is 8635.
```
telnet <DB instance address> {8635}
```
- If the port can be connected, the network is normal. Check the database account and password. For details, see Connecting to a DDS DB Instance.
- If the port cannot be connected, contact post-sales technical support for troubleshooting.