  Shared edge computing platforms, which enable Application Service Providers
(ASPs) to deploy applications in close proximity to mobile users are providing
ultra-low latency and location-awareness to a rich portfolio of services.
Though ubiquitous edge service provisioning, i.e., deploying the application at
all possible edge sites, is always preferable, it is impractical due to often
limited operational budget of ASPs. In this case, an ASP has to cautiously
decide where to deploy the edge service and how much budget it is willing to
use. A central issue here is that the service demand received by each edge
site, which is the key factor of deploying benefit, is unknown to ASPs a
priori. What's more complicated is that this demand pattern varies temporally
and spatially across geographically distributed edge sites. In this paper, we
investigate an edge resource rental problem where the ASP learns service demand
patterns for individual edge sites while renting computation resource at these
sites to host its applications for edge service provisioning. An online
algorithm, called Context-aware Online Edge Resource Rental (COERR), is
proposed based on the framework of Contextual Combinatorial Multi-armed Bandit
(CC-MAB). COERR observes side-information (context) to learn the demand
patterns of edge sites and decides rental decisions (including where to rent
the computation resource and how much to rent) to maximize ASP's utility given
a limited budget. COERR provides a provable performance achieving sublinear
regret compared to an Oracle algorithm that knows exactly the expected service
demand of edge sites. Experiments are carried out on a real-world dataset and
the results show that COERR significantly outperforms other benchmarks.
