Rails app crashes when connecting remotely to MySQL Database on Heroku

Question

We are running a Ruby on Rails on Heroku. We're trying to connect to a remote database connection. We have tried the below methods

heroku config:add DATABASE_URL=mysql://XXXXXX We have tried both mysql and mysql2

We are seeing H99 errror "H99 is the only error that is caused by the Heroku platform" in our logs. Console connection works, migrations works. Do you guys have any ideas? Thanks!

Answer 1

It can be over just by runnig:

heroku ps:scale web=0

and then

heroku ps:scale web=1

Answer 2

H99 is something only Heroku can fix. I would raise a support ticket.