Mysql2::Error (Access denied for user'b00120fa21c0f6'@'ip-10-139-25-93.ec2.internal' (using password: YES)) :

Environment
heroku
ClearDB MySQL

I'm running the Rails app with Heroku, but while I was working on it, "We're sorry, but something wrong." and the app stopped working.
When I looked at the Heroku log, I found the following error statement:
I looked into it, but I don't know how to solve it, so I would like your advice.
Thank you for your cooperation.

error statement
Mysql2::Error (Access denied for user'b00120fa21c0f6'@'ip-10-139-25-93.ec2.internal' (using password: YES))

database.yml
default:&default
adapter:mysql2
encoding:utf8
pool:5
username:root
password:
socket: /var/run/mysqld/mysqld.sock
template:template0