Analysis of an offloading scheme for data centers in the framework of fog computing

Christine Fricker (1, 2) , Fabrice Guillemin (3) , Philippe Robert (1) , Guilherme Raposo Thompson (1)

1 RAP - Networks, Algorithms and Probabilities
2 DYOGENE - Dynamics of Geometric Networks
3 Orange Labs [Issy les Moulineaux]

In the context of fog computing, we consider a simple case when data centers installed at the edge of the network are backed up by a central (bigger) data center. The system considered precisely comprises two data centers in parallel. We assume that if a request arrives at an overloaded data center, it is forwarded to the other data center with a given probability. Both data centers are assumed to have a large number of servers (rescaling of the system) and that traffic to one of them is causing saturation so that the other data center may help to cope with this saturation regime by reducing the rejection of requests. Our aim here is to qualitatively estimate the gain achieved by the collaboration of the two data centers. After proving some convergence results, related to the scaling limits of loss systems, for the process describing the number of free servers at both data centers, we show that the performance of the system can be expressed in terms of the invariant distribution of a random walk in the quarter plane. By using and developing existing results in the technical literature, explicit formulas for the blocking rates of such a system are derived.

Mots clés: Functional Equations; Markov Processes; Random Walks; Queueing Theory

Domaines: Informatique [cs]

Christine Fricker, Fabrice Guillemin, Philippe Robert, Guilherme Raposo Thompson. Analysis of an offloading scheme for data centers in the framework of fog computing. ACM Transactions on Modeling and Performance Evaluation of Computing Systems, 2016, 1 (4), pp.18. ⟨10.1145/2950047⟩. ⟨hal-01179206⟩