Migrate is a system service that allows network applications to suspend upon disconnection and properly resume when connectivity is restored. Migrate uses session continuations, which allow applications to explicitly record all the state and resources required to correctly resume. Migrate virtualizes network connections to function across network address changes, allows portions of an application to be suspended and securely resumed, and optimizes scarce system resources on servers handling many suspended clients. We demonstrate that the continuation abstraction is both useful and efficient by showing how two important applications, SSH and Icecast, can use Migrate to implement a suspend/resume feature. We find that the required source code changes are between 0.5% and 1.75% of the total, that the generated continuations are between 1% and 5% of the memory footprint of the entire process, and that session resumption times are small (a few hundred milliseconds) compared to typical disconnection durations. We also show that he proposed system is scalable to support large number of simultaneous requests for suspension/resumption.

Pre-2018 CSE ID: CS2008-0921