An Analysis of Trace Data for Predictive File Caching in Mobile Computing

One way to provide mobile computers with access to the resources of a network, even in the absence of communication, is to predict which information will be used during disconnection and cache the appropriate data while still connected. To determine the feasibility of this approach, traces of file-access activity for three diverse application domains were collected for periods of over two months. Analysis of these traces using traditional and new measures reveals that user working sets tend to be small compared to modern disk sizes, that users tend to reference the same files for several days or even weeks at a time, and that different users do not tend to write to the same file except in highly constrained circumstances. These factors encourage the conclusion that an automated caching system can be built for a wide variety of environments. 1 Motivation The value of mobile computers is that they allow users to work while disconnected from their normal resources. However, mobile comput..