BOn... tout pile ce que je pensais...
• Availability of unpopular videos: Consider again Figure 13.
Let us now focus on the observation that several videos are
downloaded exactly once from the non-preferred data center.
Further analysis indicated that for most datasets, over 99% of
these videos were accessed exactly once in the entire dataset,
with this access being to non-preferred data centers. However,
when the videos were accessed more than once, only the first
access was redirected to a non-preferred data center.
This observation leads us to hypothesize that downloads
from non-preferred data centers can occur because of the
limited popularity of the videos. In particular, videos that are
rarely accessed may be unavailable at the preferred data center,
causing the user requests to be redirected to non-preferred data
centers until the video is found
