Process-aware continuation management in web applications

• Continuations are used to cope with unforeseen user navigation in web applications.
• However, their management can incur significant memory overhead under heavy load.
• We present mechanisms for pruning continuation trees based on the dialog structure.
• This also prevents users from backtracking into completed transactions through the GUI.
• Depending on the structure of the dialogs, this enables significant memory savings.

Web applications are subject to an interaction challenge not found in other user interfaces: In addition to the widgets that web pages are built of, browsers provide further navigation features such as the Back and Forward buttons that are beyond the developer's control. Continuations have been suggested as a means to cope with the arbitrary navigation patterns that users may perform using these features. While an elegant solution in theory, continuations can incur a significant memory load in practice, and may offer more navigation options than business requirements mandate. We therefore propose a dialog control logic that augments the continuation approach with strategies for automatic elimination of continuations that will likely not be needed anymore, or whose invocation shall be prevented due to business requirements. This way, we aim to realize the benefits that continuations can provide to web applications, while ameliorating the drawbacks that they exhibit in practice.