How to Safely Restart a Heroku App: Strategies and Techniques

As a developer or administrator of a Heroku app, there may come a time when you need to restart your application. This process can help resolve issues, apply changes, or manage costs effectively. This article will guide you through restarting a Heroku app from the web dashboard and using the Heroku command-line tool. Additionally, we will explore cost management tactics for review apps on Heroku.

Restaring a Heroku App from the Web Dashboard

To restart a Heroku app from the web dashboard, follow these steps:

Log in to Heroku: Access the Heroku website and log in to your account. Access Your Dashboard: Once logged in, navigate to your Heroku dashboard. You can find this by clicking on your name or profile icon in the top right corner and selecting your app from the dropdown menu. Select Your App: From the dashboard, click on the app you want to restart. Go to the Apps Overview Page: On the apps overview page, look for the More button in the upper right corner and select Restart all dynos. Restart Your App: Click on the Restart all dynos option. This will restart all the dynos for your app, which can help resolve issues or apply changes.

It's important to note that you can also restart a Heroku app using the command-line tool. The command to restart all dynos is:

heroku restart -a app_name

Alternatively, if you want to restart individual dynos, you can use the following command:

heroku ps:restart web.1

Here, web.1 is the name and number of your dyno. You can adjust the command to match the specific dyno you need to restart.

Managing Cost with Review Apps and AutoIdle Add-on

For temporary apps like review apps, it's essential to manage costs efficiently. Review apps are incredibly useful for validating changes during pull request code reviews, but they can be costly if left running for long periods. Therefore, it's crucial to put your review apps to sleep when they are not in use to save money.

One effective way to manage these costs is to use AutoIdle, a Heroku add-on. AutoIdle automatically puts your staging and review apps to sleep after 30 minutes of inactivity. However, when an HTTP request is received, the app is reactivated. This is perfect for temporary apps that don’t need to stay active all the time.

For production apps, it’s crucial to avoid interruptions in service. Therefore, AutoIdle should not be used in the production environment. If you need to scale your dynos up and down, you can use the command:

heroku ps:scale web.x0

Then, when you're ready to bring the dynos back online, you can use:

heroku ps:scale web.x1

This will bring back the original set of dynos, giving you a chance to restart them without downtime. Scaling up and back down the dynos can be an effective way to manage costs while ensuring that your production app remains available.

Conclusion

Restarting a Heroku app is a straightforward process that can help resolve issues and apply changes. Whether you're working with review apps or production environments, knowing how to manage costs and downtime is essential. By utilizing the web dashboard and command-line tools, as well as add-ons like AutoIdle, you can effectively manage your Heroku app's lifecycle and ensure it runs smoothly and cost-effectively.

Keywords: Heroku App Restart, Dynos Restart, Review Apps Management, AutoIdle Add-on, Heroku Command Restart