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E. Hyytiä, R. Righter and S. Aalto, Task Assignment in a Heterogeneous Server Farm with Switching Delays and General Energy-Aware Cost Structure, Performance Evaluation, vol. 75--76, no. 0, pp. 17-35, 2014.

Abstract: We consider the task assignment problem to heterogeneous parallel servers with switching delay, where servers can be switched off to save energy. However, switching a server back on involves a constant server-specific delay. We will use one step of policy iteration from a starting policy such as Bernoulli splitting, in order to derive efficient task assignment (dispatching) policies that minimize the long-run average cost. To evaluate our starting policy, we first analyze a single work-conserving M/G/1 queue with a switching delay and derive a value function with respect to a general cost structure. Our costs include energy related switching and processing costs, as well as general performance-related costs, such as costs associated with both means and variability of waiting time and sojourn time. The efficiency of our dispatching policies is illustrated with numerical examples.

Links: DOI (pdf)

BibTeX entry:

@article{hyytia-peva-2014,
  title = {Task Assignment in a Heterogeneous Server Farm with Switching Delays and General Energy-Aware Cost Structure},
  author = {Esa Hyyti{\"a} and Rhonda Righter and Samuli Aalto},
  journal = {Performance Evaluation},
  doiopt = {10.1016/j.peva.2014.01.002},
  volume = {75--76},
  number = {0},
  month = {May-June},
  year = {2014},
  pages = {17--35},
  doiopt = {10.1016/j.peva.2014.01.002}
}