Adaptive Redistribution and Replication to Improve the Responsiveness of Mobile Web Apps

Abstract

In a mobile web app, a browser-based client communicates with a cloud-based server across the network. An app is statically divided into client and server functionalities, so the resulting division remains fixed at runtime. However, if such static division mismatches the current network conditions and the device’s processing capacities, app responsiveness and energy efficiency can deteriorate rapidly. To address this problem, we present Communicating Web Vessels (CWV), an adaptive redistribution and replication framework that improves the responsiveness of full-stack JavaScript mobile apps. Unlike standard computation offloading, in which client functionalities move to run on the server, CWV’s redistribution is bidirectional. Without any preprocessing, CWV enables apps to move any functionality from the server to the client and vice versa at runtime, thus adapting to the ever-changing execution environment of the web. Having moved to the client, former server functionalities become regular local functions. To further improve performance, CWV can replicate server-side functionalities on the client and keep the replicas consistent. By monitoring the network, CWV determines if a redistribution or a replication would improve app performance, and then analyzes, transforms, sandboxes, moves, or replicates functions and program state at runtime. An evaluation with third-party mobile web apps shows that CWV optimizes their performance for dissimilar network conditions and client devices. As compared to their original versions, CWV-powered web apps improve their performance (i.e., latency, energy consumption), particularly when executed over limited networks.1