Cost–Performance Optimization of Application- and Context-Aware Distributed Infrastructures

Application- and context-aware infrastructures involve the network in the execution of distributed applications through special devices, namely, the application cards, placed in network nodes. The sharp separation of applications and network is smoothed, and by performing part of the distributed application inside the network, it is possible to reduce costs and improve performance with a better optimization of the whole distributed information and communication technology (ICT) infrastructure. This optimization is allowed by the additional degrees of freedom of placing cards in nodes and of assigning applications to such cards. In this paper, we provide an optimization algorithm that minimizes the total cost of the entire distributed ICT infrastructure, given a target performance objective defined as the end-to-end delay for the completion of the distributed application tasks. We focus on two sample applications that are well suited for application- and context-aware infrastructures: caching and protocol translation. The joint optimization of computing and communication resources is an innovative contribution of this paper, as, in the literature, hardware and network components are typically optimized separately. Results show that the total infrastructural cost savings are in the range of 15%-20%. However, savings can be obtained only if cards satisfy a cost-performance curve that is also analyzed.