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Motivated by the increasing popularity of hosting in-memory big-data analytics in cloud, we present a profiling methodology that can understand how different memory subsystems, i.e., cache and memory bandwidth, are susceptible to the impact of interference from co-located applications. We first describe the design of the proposed tool and demonstrate a case study consisting of five Spark applications...
A transcriptomic analysis of bacteroids isolated from soybean plants inoculated with B. japonicum USDA 110, relative to cells cultured in HM-arabinose medium was performed and the results combined with two other transcriptomic analyses to form a reiterated pool of transcripts that define genes expressed during symbiotic nitrogen fixation. The majority of annotated genes represented in the reiterated...
P2P-TV systems performance are driven by the overlay topology that peers form. Several proposals have been made in the past to optimize it, yet little experimental studies have corroborated results. The aim of this work is to provide a comprehensive experimental comparison of different strategies for the construction and maintenance of the overlay topology in P2P-TV systems. To this goal, we have...
One of the prevalent trends in emerging large scale multi-tenant datacenters is network virtualization using overlays. Here we investigate application performance degradation in such an overlay applied to commodity 10 Gigabit Ethernet networks. We have adopted partition/aggregate as a representative commercial workload that today is deployed on bare metal servers and is notoriously sensitive to latency...
In this paper we consider mesh based P2P streaming systems focusing on the problem of regulating peer upload rate to match the system demand while not overloading each peer upload link capacity. We propose Hose Rate Control (HRC), a novel scheme to control the speed at which peers offer chunks to other peers, ultimately controlling peer uplink capacity utilization. This is of critical importance for...
Peer to Peer streaming (P2P-TV) applications have recently emerged as cheap and efficient solutions to provide real time streaming services over the Internet. For the sake of simplicity, typical P2P-TV systems are designed and optimized following a pure layered approach, thus ignoring the effect of design choices on the underlying transport network. This simple approach, however, may constitute a...
Open source routers (OSR), i.e. routers running on commodity personal computers (PC), represent a valid alternative to proprietary hardware routers. However, they may suffer from performance impairments and software limitations. Multistage architectures, based on the interconnection of elements running on standard PCs, improve single stage OSR performance. Virtualization technologies may permit to...
P2P-TV systems have become part of the Internet landscape. The architecture of these (normally proprietary) applications is generally receiver-driven, in that receivers actively search for suitable peers to download from, trying to maximize their performance. The Napa-Wine EU project proposes an architecture where P2P-TV clients exploit network measures to reduce their network footprint and, if available,...
OpenFlow is an open standard that can be implemented in Ethernet switches, routers and wireless access points (AP). In the OpenFlow framework, packet forwarding (data plane) and routing decisions (control plane) run on different devices. OpenFlow switches are in charge of packet forwarding, whereas a controller set up switch forwarding table on a per-flow basis, to enable flow isolation and resource...
As the Internet owes its scalability and stability to TCP, congestion control also plays a key role in the performance, efficiency, and stability of datacenters, as evidenced by the efforts to standardize congestion management (CM) for 10+ Gbps networks. The next step up from datacenters is CM for clouds. New solutions are necessary for clouds because, while the recent CM schemes have been tested...
Recent research in the different functional areas of modern routers have made proposals that can greatly increase the efficiency of these machines. Most of these proposals can be implemented quickly and often efficiently in software. We wish to use personal computers as forwarders in a network to utilize the advances made by researchers. We therefore examine the ability of a personal computer to act...
Software routers based on personal computer (PC) architectures are receiving increasing attention in the research community. However, a router based on a single PC suffers from limited bus and central processing unit (CPU) bandwidth, high memory access latency, limited scalability in terms of number of network interface cards, and lack of resilience mechanisms. Multi-stage architectures created by...
Increasing attention has been recently devoted to software routers based on off-the-shelf hardware and open-source operating systems running on personal computer (PC) architectures. Today's high-end PCs PCI shared buses fit into the multi-gigabit-per-second routing segment, for a price much lower than that of commercial routers. However, commercially available Network Interface Cards (NICs) lack programmability,...
VoIP has widely been addressed as the technology that will change the Telecommunication model opening the path for convergence. Still today this revolution is far from being complete, since the majority of telephone calls are originated by circuit-oriented networks. In this paper for the first time to the best of our knowledge, we present a large dataset of measurements collected from the FastWeb...
The research community is devoting increasing attention to software routers based on off-the-shelf hardware and open-source operating systems running on the personal-computer (PC) architecture. Today's high-end PCs are equipped with peripheral component interconnect (PCI) shared buses enabling them to easily fit into the multi-gigabit-per-second routing segment, for a price much lower than that of...
We report the case of a 77–year–old man who developed a Strongyloides hyperinfection syndrome following immunosuppressive therapy more than 60 years after he moved away from an area endemic for Strongyloides stercoralis. Successful eradication of the nematode was achieved with an off label subcutaneous formulation of ivermectin. However, the patient subsequently died from acute respiratory distress...
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