Why is my app crashing with an R10 error?

R10 - Boot timeout errors occur when a web process took longer than 60 seconds to bind to its assigned $PORT.

This error is often caused by a process being unable to reach an external resource, such as a database, or the application doing too much work, such as parsing and evaluating numerous, large code dependencies, during startup.

The default boot timeout is 60 seconds. An exception is for apps using the Java buildpack, Gradle buildpack, heroku-deploy toolbelt plugin, or Heroku Maven plugin, which will be allowed 90 seconds to bind to their assigned port.

Some related help articles:

As a last resort, if your application requires more time to boot, you may use the boot timeout tool to increase the limit. However, in general, slow boot times will make it harder to deploy your application and will make recovery from dyno failures slower, so this should be considered a temporary solution.

Ask on Stack Overflow

Engage with a community of passionate experts to get the answers you need

Ask on Stack Overflow

Heroku Support

Create a support ticket and our support experts will get back to you

Contact Heroku Support