Can't connect to RDS instance from EC2 instance

Question

From EC2 instance i-78a8df00, I\'m trying to connect to RDS instance mysql.************.us-east-1.rds.amazonaws.com. They are both in the U.S. East region. I added the secur

Answer 1

I had the similar problem today when my EC2 instance suddenly lost access to RDS instance and Wordpress stopped working. The security groups were correct and I could even connect to MySQL from console on EC2 instance but not from PHP. For some reason restarting EC2 server helped me.