eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Leibniz International Proceedings in Informatics
1868-8969
2019-11-28
39:1
39:12
10.4230/LIPIcs.ISAAC.2019.39
article
A Competitive Algorithm for Random-Order Stochastic Virtual Circuit Routing
Nguyễn Kim, Thắng
1
https://orcid.org/0000-0002-6085-9453
IBISC, Univ Evry, University Paris Saclay, Evry, France
We consider the virtual circuit routing problem in the stochastic model with uniformly random arrival requests. In the problem, a graph is given and requests arrive in a uniform random order. Each request is specified by its connectivity demand and the load of a request on an edge is a random variable with known distribution. The objective is to satisfy the connectivity request demands while maintaining the expected congestion (the maximum edge load) of the underlying network as small as possible.
Despite a large literature on congestion minimization in the deterministic model, not much is known in the stochastic model even in the offline setting. In this paper, we present an O(log n/log log n)-competitive algorithm when optimal routing is sufficiently congested. This ratio matches to the lower bound Omega(log n/ log log n) (assuming some reasonable complexity assumption) in the offline setting. Additionally, we show that, restricting on the offline setting with deterministic loads, our algorithm yields the tight approximation ratio of Theta(log n/log log n). The algorithm is essentially greedy (without solving LP/rounding) and the simplicity makes it practically appealing.
https://drops.dagstuhl.de/storage/00lipics/lipics-vol149-isaac2019/LIPIcs.ISAAC.2019.39/LIPIcs.ISAAC.2019.39.pdf
Approximation Algorithms
Congestion Minimization