  Multi-tenancy in resource-constrained environments is a key challenge in Edge
computing. In this paper, we develop 'DYVERSE: DYnamic VERtical Scaling in
Edge' environments, which is the first light-weight and dynamic vertical
scaling mechanism for managing resources allocated to applications for
facilitating multi-tenancy in Edge environments. To enable dynamic vertical
scaling, one static and three dynamic priority management approaches that are
workload-aware, community-aware and system-aware, respectively are proposed.
This research advocates that dynamic vertical scaling and priority management
approaches reduce Service Level Objective (SLO) violation rates. An online-game
and a face detection workload in a Cloud-Edge test-bed are used to validate the
research. The merits of DYVERSE is that there is only a sub-second overhead per
Edge server when 32 Edge servers are deployed on a single Edge node. When
compared to executing applications on the Edge servers without dynamic vertical
scaling, static priorities and dynamic priorities reduce SLO violation rates of
requests by up to 4% and 12% for the online game, respectively, and in both
cases 6% for the face detection workload. Moreover, for both workloads, the
system-aware dynamic vertical scaling method effectively reduces the latency of
non-violated requests, when compared to other methods.
