我正在这里描述的多个环境下运行 Heroku 应用程序。我能够在我原来的单一环境下正常运行，但是当我推送到其他一个环境并运行时，heroku run rake db:migrate --remote REMOTE_NAME我得到一个错误的形式Error: Operation timed out - connect(2) (Errno::ETIMEDOUT)。
此实例的heroku logs输出如下：
heroku[api]: Starting process with command `rake db:migrate`
heroku[run.9488]: Awaiting client
heroku[run.9488]: Starting process with command `rake db:migrate`
heroku[run.9488]: Error R99 (Platform error) -> Failed to launch the dyno within 10 seconds
heroku[run.9488]: Stopping process with SIGKILL
heroku[run.9488]: Error R13 (Attach error) -> Failed to attach to process
heroku[run.9488]: Process exited with status 128
heroku[run.9488]: State changed from starting to complete
使用多个部署环境时迁移数据库的正确过程是什么？