A fundamental challenge in large-scale cloud networks and data centers is to achieve highly efficient server utilization and limit energy consumption, while providing excellent user-perceived performance in the presence of uncertain and time-varying demand patterns. Auto-scaling provides a popular paradigm for automatically adjusting service capacity in… (More)
We consider a system of <i>N</i> parallel queues with unit exponential service rates and a single dispatcher where tasks arrive as a Poisson process of rate λ(<i>N</i>). When a task arrives, the dispatcher assigns it to a server with the shortest queue among <i>d</i>(<i>N</i>) ≤ <i>N</i> randomly selected servers. This load balancing policy is… (More)
We consider a system of N identical parallel server pools and a single dispatcher where tasks arrive as a Poisson process. Arriving tasks cannot be queued, and must immediately be assigned to one of the server pools to start execution. The execution times are assumed to be exponentially distributed, and do not depend on the number of tasks contending for… (More)
The k-section width and the Max-Cut for the configuration model are shown to exhibit phase transitions according to the values of certain parameters of the asymptotic degree distribution. These transitions mirror those observed on Erd˝ os-Rényi random graphs, established by Luczak and McDiarmid (2001), and Coppersmith et al. (2004), respectively.
Traditionally, reconfiguration problems ask the question whether a given solution of an optimization problem can be transformed to a target solution in a sequence of small steps that preserve feasibility of the intermediate solutions. In this paper, rather than asking this question from an algorithmic perspective, we analyze the combinatorial structure… (More)