问题
I have one EC2 instance that can connect to RDS, and another that can't.
- They are in the same VPC/Subnet/AZ
- They have the same IAM role
- They have different (but similar) security groups, both allow all inbound
- The subnets are showing in the configuration for the RDS instance
- The ec2 instance that can't connect just times out
What could be going wrong? Is there any way to work out where the connection is failing?
来源：https://stackoverflow.com/questions/43898381/ec2-instance-cant-connect-to-rds-from-same-vpc-subnet