Sometimes web applications require application-wide objects that live beyond the request-response life cycle, such as database connections, application configuration, shared objects, and cross-cutting concerns (authentication, error handling, and so on). Consider the following:
Ensuring that the database used by the application is defined and accessible.
Notify through e-mail or any other service when the application is receiving unexpected heavy traffic.
Logging the different requests served by the application. These logs can later be used to analyze user behavior.
Restricting certain facilities on the web application by time. For example, some food ordering apps take orders only between 11 a.m. to 8 p.m., while all requests to build orders at any other time will be blocked and a message about the timings will be displayed.
Generally, when a user sends an e-mail and the recipient's email ID is incorrect or not in use, the sender is notified about the failure in...