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Network Function Virtualization (NFV) is a novel paradigm that enables flexible and scalable implementation of network services on cloud infrastructure. An important enabler for the NFV paradigm is software switching, which should satisfy rigid network requirements such as high throughput and low latency. Despite recent research activities in the field of NFV, not much attention was given to understand...
Computer architects use a variety of workloads to measure system performance. For many workloads, the workload configuration determines the stress applied to the system and the corresponding performance behavior. Therefore, architects must make great efforts to explore and find the correct workload configuration before performing detailed analysis. However, such explorations become impossible for...
Motivated by the increasing trend of storing data for web applications in fast NoSQL systems, in this paper, we experiment with the leading NoSQL datastore — Cassandra — and a latest generation re-design of Cassandra — ScyllaDB — meant to deliver bleeding-edge performance on modern multicore machines. We evaluate the scalability claim of ScyllaDB, in terms of the number of clients, and provide diagnostic...
In current Data Center Networks (DCNs), Equal- Cost MultiPath (ECMP) is used as the de-facto routing protocol. However, ECMP does not differentiate between short and long flows, the two main categories of flows depending on their duration (lifetime). This issue causes hot-spots in the network, affecting negatively the Flow Completion Time (FCT) and the throughput, the two key performance metrics in...
Many high-performance computing (HPC) sites extend their clusters to support Hadoop MapReduce for a variety of applications. However, HPC cluster differs from Hadoop cluster on the configurations of storage resources. In the Hadoop Distributed File System (HDFS), data resides on the compute nodes, while in the HPC cluster, data is stored on separate nodes dedicated to storage. Dedicated storage offloads...
High throughput is of particular interest in data center and HPC networks. Although myriad network topologies have been proposed, a broad head-to-head comparison across topologies and across traffic patterns is absent, and the right way to compare worst-case throughput performance is a subtle problem. In this paper, we develop a framework to benchmark the throughput of network topologies, using a...
In today's data centers, storage hardware is getting virtualized and shared across multiple tenants. The storage virtualization is expected to significantly increase resource utilization, and consequently provide infrastructure providers with tremendous cost savings. In a shared environment, however, demanding tenants can severely impact the IO performance of co-located tenants. Therefore, in order...
Growth in cloud computing motivates cloud networks that provide excellent performance and scalability. Improvements rely on the ability to measure these characteristics. Measurement is complicated by a combinatorial explosion of implementations, configurations, metrics, workloads and scenarios. We present tools and a framework that facilitate performance and scalability evaluation. We present the...
In the Software Defined Network (SDN) ecosystem, the controller remains the cornerstone of the architecture and the critical point of its success. That is why performance concerns have existed throughout the history of SDN and controller development. This paper aims at making a reality check on the current performance achieved by mainstream open source controllers. The measurements are carried out...
HTTP ABR Video Streaming based methods are being used by certain media players and video servers. With this, video is encoded with different data rates, stored on a content server (if possible) and streamed to different client devices. Media player at client device considers various performance factors and decides the rate that it should ask for the next video segment. There are different types of...
In this paper, we evaluate the performance of per-packet load balancing in data center networks (DCNs). Throughput and flow completion time are considered among the main metrics to evaluate the performance of the transport of flows over the presence of long flows in a DCN. Load balancing in a DCN may benefit those performance metrics but also it may generate out-of-order packet delivery. We investigate...
Network function virtualization (NFV) introduces additional complexity to network management, since the placement and behavior of virtualized network functions (VNFs) can be independent from the underlying hardware, and virtualization technology increases the number of monitoring points and the amount of statistical data. In our previous work, we proposed a framework for detecting anomalous behavior...
Vehicular Ad-hoc NETworks (VANETs) have unique characteristics, such as the high mobility of nodes, which cause frequent losses of connectivity, turning technology and network selection into a complex problem. Moreover, due to the instability of networks and its fast change, this network selection requires information of the networks in advance, so that it can predict the quality of the networks to...
Video delivery performance is the main factor that affects Internet video quality. Characterizing the video delivery performance, especially the delivery throughput, can help content providers as well as Internet service providers (ISPs) in system optimization and network planning. Based on a unique dataset consisting of 20 million video download speed measurements , this paper comprehensively studies...
While workload collocation is a necessity to increase energy efficiency of contemporary multi-core hardware, it also increases the risk of performance anomalies due to workload interference. Pinning certain workloads to a subset of CPUs is a simple approach to increasing workload isolation, but its effect depends on workload type and system architecture. Apart from common sense guidelines, the effect...
We aim at enhancing the Quality of Service (QoS) management in modern Internet applications that heavily rely on the quality of the underlying network. Our goal is to provide the application developers with mechanisms for specifying and controlling high-level, application-related QoS metrics, rather than the traditional low-level, network-related metrics like latency, throughput, packet loss, etc...
Residential wireless networks have grown rapidly in the past decade. Meanwhile, dense deployments and autonomous managements of home Access Points (APs) greatly increase channel congestion levels and degrade the user experience. To address such problems, this paper proposes an architecture in residential environments called Wi-Fi Union (WU), where home APs can voluntarily join WU and become "member...
The Constrained Application Protocol (CoAP) is a new Web protocol for the Internet of Things that allows to connect IoT devices directly to services hosted in the cloud. CoAP is based on UDP to better fit the requirements of constrained environments with resource-constrained nodes and low-power communication links. Being an Internet protocol, CoAP must still adhere to congestion control, primarily...
Data protection using backup is one of the most critical IT management operations to ensure business continuity, which is also constantly evolving due to the emerging challenges in the “Big Data Era.” In this paper, we introduce our ongoing research effort in designing intelligent enterprise backup management solutions by obtaining actionable insights from voluminous backup job metadata across data...
Quality of Service (QoS) metrics have been traditionally used to evaluate the perceived quality of services delivered by network operators. However, these metrics are not suitable for evaluating the experience of an end-user. The experience of a user is quantified based upon activities such as speed of web page loading, quality of video streaming, or voice quality of Internet-telephony. Due to the...
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