Network virtualization is a paradigm that allows for flexible and efficient
allocation of the resources among multiple virtual networks (VNets). In this
paper we deal with the problem of embedding dynamically arriving VNet requests.
We describe a generic algorithm for the online VNet embedding problem and
analyze its competitive ratio. This means that we compare the benefit
accumulated by the algorithm with the benefit of an optimal offline algorithm.
We prove that the competitive ratio of our online algorithm is, loosely
speaking, logarithmic in the sum of the resources.