Resilient network dimensioning for optical grid/clouds using relocation

In this paper we address the problem of dimensioning infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We will provide an overview of our work in this area, and in particular focus on how to design the resulting grid/cloud to be resilient against network link and/or server site failures. To this end, we will exploit relocation: under failure conditions, a request may be sent to an alternate destination than the one under failure-free conditions. We will provide a comprehensive overview of related work in this area, and focus in some detail on our own most recent work. The latter comprises a case study where traffic has a known origin, but we assume a degree of freedom as to where its end up being processed, which is typically the case for e. g., grid applications of the bag-of-tasks (BoT) type or for providing cloud services. In particular, we will provide in this paper a new integer linear programming (ILP) formulation to solve the resilient grid/cloud dimensioning problem using failure-dependent backup routes. Our algorithm will simultaneously decide on server and network capacity. We find that in the anycast routing problem we address, the benefit of using failure-dependent (FD) rerouting is limited compared to failure-independent (FID) backup routing. We confirm our earlier findings in terms of network capacity savings achieved by relocation compared to not exploiting relocation (order of 6-10% in the current case studies)

Joint dimensioning of server and network infrastructure for resilient optical grids/clouds

We address the dimensioning of infrastructure, comprising both network and server resources, for large-scale decentralized distributed systems such as grids or clouds. We design the resulting grid/cloud to be resilient against network link or server failures. To this end, we exploit relocation: Under failure conditions, a grid job or cloud virtual machine may be served at an alternate destination (i.e., different from the one under failure-free conditions). We thus consider grid/cloud requests to have a known origin, but assume a degree of freedom as to where they end up being served, which is the case for grid applications of the bag-of-tasks (BoT) type or hosted virtual machines in the cloud case. We present a generic methodology based on integer linear programming (ILP) that: 1) chooses a given number of sites in a given network topology where to install server infrastructure; and 2) determines the amount of both network and server capacity to cater for both the failure-free scenario and failures of links or nodes. For the latter, we consider either failure-independent (FID) or failure-dependent (FD) recovery. Case studies on European-scale networks show that relocation allows considerable reduction of the total amount of network and server resources, especially in sparse topologies and for higher numbers of server sites. Adopting a failure-dependent backup routing strategy does lead to lower resource dimensions, but only when we adopt relocation (especially for a high number of server sites): Without exploiting relocation, potential savings of FD versus FID are not meaningful

SMART - IWRM - Sustainable Management of Available Water Resources with Innovative Technologies - Integrated Water Resources Management in the Lower Jordan Rift Valley : Final Report Phase II (KIT Scientific Reports ; 7698)

SMART was a multi-lateral research project with partners from Germany, Israel, Jordan and the Palestinian Territories. The overall goal was to develop a transferable approach for Integrated Water Resources Management (IWRM) in the water shortage region of the Lower Jordan Valley. The innovative aspect addressed all available water resources: groundwater and surface waters, but also wastewater, brackish water and flood water that need to be treated for use

A Hybrid Method for Solving ARWA Problem on WDM Network

[[abstract]]Anycast refers to the transmission of data from a source node to (any) one member in the group of designed recipients in a network. In WDM network, the anycast requests can be used as an optimization tool to ensure survivability. If the anycast requests can be routed and delivered carefully, it is enough to find more free lightpath (or wavelengths) to other traffic (unicast or multicast). When the WDM network and the set of anycast requests are given, the anycast routing and wavelength assignment (ARWA) problem is to find a set of light-paths, one for each source, for anycasting messages to any one of the member in the anycast destination group such that not any path using the same wavelength passes through the same link. The goal of the ARWA problem is to minimize the number of used wavelengths. In this paper, the ARWA problem is formulated and studied; since ARWA problem is NP-hard, a hybrid method which combines simulated annealing and genetic algorithm technologies is proposed to solve it. In the proposed algorithm, the random routing method is used to generate the routing path from source to destination, heuristic algorithm is used to find the assigning wavelength of routing path. Nine types of perturbation schemes are proposed to generate the neighboring configuration, these perturbation schemes can avoid the proposed algorithm to trap into local optimum. Moreover, iterative improving technique is used to reduce the computing time for finding the new wavelength assignment. Simulated results show that the proposed algorithm can get better performance than other GA and heuristic algorithms