Every application block deployed as a web application provides a health check URL. An HTTP GET request for this URL returns ok if the block is ready to work.

The URL paths for different blocks are listed below:

So for an application named app and deployed at localhost:8080 the URLs will be:

You can replace ok in response with any text using the cuba.healthCheckResponse application property.

The health check controllers also send an application event of type HealthCheckEvent. Therefore you can add your own logic of checking the application health. In the example on GitHub, a bean of the web tier listens to the health check events and invokes a middleware service, which in turn executes an operation on the database.