dReDBox: Materializing a full-stack rack-scale system prototype of a next-generation disaggregated datacenter

Current datacenters are based on server machines, whose mainboard and hardware components form the baseline, monolithic building block that the rest of the system software, middleware and application stack are built upon. This leads to the following limitations: (a) resource proportionality of a multi-tray system is bounded by the basic building block (mainboard), (b) resource allocation to processes or virtual machines (VMs) is bounded by the available resources within the boundary of the mainboard, leading to spare resource fragmentation and inefficiencies, and (c) upgrades must be applied to each and every server even when only a specific component needs to be upgraded. The dRedBox project (Disaggregated Recursive Datacentre-in-a-Box) addresses the above limitations, and proposes the next generation, low-power, across form-factor datacenters, departing from the paradigm of the mainboard-as-a-unit and enabling the creation of function-block-as-a-unit. Hardware-level disaggregation and software-defined wiring of resources is supported by a full-fledged Type-1 hypervisor that can execute commodity virtual machines, which communicate over a low-latency and high-throughput software-defined optical network. To evaluate its novel approach, dRedBox will demonstrate application execution in the domains of network functions virtualization, infrastructure analytics, and real-time video surveillance.This work has been supported in part by EU H2020 ICTproject dRedBox, contract #687632.Peer ReviewedPostprint (author's final draft

Cache-Aware Memory Manager for Optimistic Simulations

Parallel Discrete Event Simulation is a well known technique for executing complex general-purpose simulations where models are described as objects the interaction of which is expressed through the generation of impulsive events. In particular, Optimistic Simulation allows full exploitation of the available computational power, avoiding the need to compute safety properties for the events to be executed. Optimistic Simulation platforms internally rely on several data structures, which are meant to support operations aimed at ensuring correctness, inter-kernel communication and/or event scheduling. These housekeeping and management operations access them according to complex patterns, commonly suffering from misuse of memory caching architectures. In particular, operations like log/restore access data structures on a periodic basis, producing the replacement of in-cache buffers related to the actual working set of the application logic, producing a non-negligible performance drop. In this work we propose generally-applicable design principles for a new memory management subsystem targeted at Optimistic Simulation platforms which can face this issue by wisely allocating memory buffers depending on their actual future access patterns, in order to enhance event-execution memory locality. Additionally, an application-transparent implementation within ROOT-Sim, an open-source generalpurpose optimistic simulation platform, is presented along with experimental results testing our proposal

An Empirical Model of Packet Processing Delay of the Open vSwitch

Network virtualization offers flexibility by decoupling virtual network from the underlying physical network. Software-Defined Network (SDN) could utilize the virtual network. For example, in Software-Defined Networks, the entire network can be run on commodity hardware and operating systems that use virtual elements. However, this could present new challenges of data plane performance. In this paper, we present an empirical model of the packet processing delay of a widely used OpenFlow virtual switch, the Open vSwitch. In the empirical model, we analyze the effect of varying Random Access Memory (RAM) and network parameters on the performance of the Open vSwitch. Our empirical model captures the non-network processing delays, which could be used in enhancing the network modeling and simulation

Quarc: a novel network-on-chip architecture

This paper introduces the Quarc NoC, a novel NoC architecture inspired by the Spidergon NoC. The Quarc scheme significantly outperforms the Spidergon NoC through balancing the traffic which is the result of the modifications applied to the topology and the routing elements.The proposed architecture is highly efficient in performing collective communication operations including broadcast and multicast. We present the topology, routing discipline and switch architecture for the Quarc NoC and demonstrate the performance with the results obtained from discrete event simulations

Evolution of Supply Chain Collaboration: Implications for the Role of Knowledge

Increasingly, research across many disciplines has recognized the shortcomings of the traditional “integration prescription” for inter-organizational knowledge management. This research conducts several simulation experiments to study the effects of different rates of product change, different demand environments, and different economies of scale on the level of integration between firms at different levels in the supply chain. The underlying paradigm shifts from a static, steady state view to a dynamic, complex adaptive systems and knowledge-based view of supply chain networks. Several research propositions are presented that use the role of knowledge in the supply chain to provide predictive power for how supply chain collaborations or integration should evolve. Suggestions and implications are suggested for managerial and research purposes

Intelligent systems in manufacturing: current developments and future prospects

Global competition and rapidly changing customer requirements are demanding increasing changes in manufacturing environments. Enterprises are required to constantly redesign their products and continuously reconfigure their manufacturing systems. Traditional approaches to manufacturing systems do not fully satisfy this new situation. Many authors have proposed that artificial intelligence will bring the flexibility and efficiency needed by manufacturing systems. This paper is a review of artificial intelligence techniques used in manufacturing systems. The paper first defines the components of a simplified intelligent manufacturing systems (IMS), the different Artificial Intelligence (AI) techniques to be considered and then shows how these AI techniques are used for the components of IMS