We also study the effect of imperfect interactions with user-side prefetch buffers on the algorithm performance. We first simulate the scenario where the proxy is unaware of the content of the prefetch buffer, and pushes documents that are already in the prefetch buffer at the user-side. The results for the (1, 1, 0.01) configuration show that the performance is degraded moderately; request savings changes from 15% to 12%, and the latency reduction changes from 9% to 7%.
We then simulate the scenario where the proxy is unaware of the user accesses that hit in the prefetch buffer. That is, the proxy would not know which of its predictions are right, and which are wrong. The results show that the performance is impacted significantly. The request savings is reduced from 15% to 8%, and the latency reduction changes from 9% to 5%.
Thus, it is important for the proxy to know the accesses that hit in the prefetch buffer. In practice, sending the information to the proxy requires a small update message from the client machine to the proxy. Our results show that this update message is important and should not be omitted.