A Comparison of wide area network performance using virtualized and non-virtualized client architectures

The goal of this thesis is to determine if there is a significant performance difference between two network computer architecture models. The study will measure latency and throughput for both client-server and virtualized client architectures. In the client server environment, the client computer performs a significant portion of the work and frequently requires downloading uploading files to and from a remote location. Virtual client architecture turns the client machine into a terminal, sending only keystrokes and mouse clicks and receiving only display pixel or sound changes. I accomplished the goal of comparing these architectures by comparing completion times for ping reply, file download, a small set of common work tasks, and a moderately large SQL database query. I compared these tasks using simulated wide area network, local area network, and virtual client network architectures. The study limits the architecture to one where the virtual client and server are in the same data center

Differential virtualization for large-scale system modeling

Today’s computer networks become more complex than ever with a vast number of connected host systems running a variety of different operating systems and services. Academia and industry alike realize that education in managing such complex systems is extremely important for computer professionals because, with computers, there are many levels of detailed configuration. Configuration points can occur during all facets of computer systems including system design, implementation, and maintenance stages. In order to explore various hypotheses regarding configurations, system modeling is employed – computer professionals and researchers build test environments. Modeling environments require observable systems that are easily configurable at an accelerated rate. Observation abilities increase through re-use and preservation of models. Historical modeling solutions do not efficiently utilize computing resources and require high preservation or restoration cost as the number of modeled systems increases. This research compares a workstation-oriented, virtualization modeling solution using system differences to a workstation-oriented, imaging modeling solution using full system states. The solutions are compared based on computing resource utilization and administrative cost with respect to the number of modeled systems. Our experiments have shown that upon increasing the number of models from 30 to 60, the imaging solution requires an additional 75 minutes; whereas, the difference-based virtualization solution requires an additional three (3) minutes. The imaging solution requires 151 minutes to prepare 60 models, while the difference-based, virtualization solution requires 7 minutes to prepare 60 models. Therefore, the cost for model archival and restoration in the difference-based virtualization modeling solution is lower than that in the full system imaging-based modeling solution. In addition, by using a virtualization solution, multiple systems can be modeled on a single workstation, thus increasing workstation resource utilization. Since virtualization abstracts hardware, virtualized models are less dependent on physical hardware. Thus, by lowering hardware dependency, a virtualized model is further re-usable than a traditional system image. If an organization must perform system modeling and the organization has sufficient workstation resources, using a differential virtualization approach will decrease the time required for model preservation, increase resource utilization, and therefore provide an efficient, scalable, and modular modeling solution

Käyttäjätason ohjelmistokontittaminen pilviradioliityntäverkossa

The amount of devices connected through mobile networks has been growing rapidly. This growth will create a demand for network capacity that cannot be met with traditional methods. This problem could be solved by implementing a cloud radio access network (RAN), a new concept, to adapt cloud computing technologies, such as software containers, from the software industry to RANs. This adaptation will also create a need to modify working practices in order to better comply with these new cloud computing technologies. While cloud RAN has recently received much research attention, the actual software implementations have not been widely discussed in the literature. Therefore, this thesis evaluates the feasibility of using software containers in the user-plane applications of cloud RAN in terms of networking and inter-container communications (ICC). This is accomplished by identifying potential approaches for ICC and for container networking as well as measuring the performance of these approaches. Two approaches are proposed for ICC and container networking. The approaches were evaluated in terms of throughput and latency. These approaches were found to be suitable for use in cloud RAN user-plane applications. However, since the measurements were performed in a simplified environment, implementing the approaches into a cloud RAN component will require further work.Mobiiliverkkoihin liitettävien laitteiden määrä kasvaa nopeasti. Tämä kasvu tulee luomaan verkon kapasiteetille kysynnän, johon ei kyetä vastaamaan perinteisin menetelmin. Tämä ongelma voitaineen ratkaista implementoimalla pilviradioliityntäverkko (Cloud RAN), uusi konsepti, joka sovittaa ohjelmistoalalla vakiintuneita pilvilaskentateknologioita käytettäväksi radioliityntäverkoissa (radio access network, RAN). Tämä sovitusprosessi luo tarpeen mukauttaa myös työskentelytavat yhteensopiviksi uusien pilvilaskentateknologioiden kanssa. Vaikka pilviradioliityntäverkkoa on tutkittu aktiivisesti viime aikoina, käytännön ohjelmistototeutukset eivät juuri ole olleet esillä kirjallisuudessa. Tämä diplomityö arvioi ohjelmistokonttien (software containers) soveltuvuutta käytettäväksi pilviradioliityntäverkon käyttäjätason (user-plane) applikaatioissa verkottamisen (networking) ja ohjelmistokonttien välisen kommunikoinnin (inter-container communications, ICC) suhteen. Tämä arviointi suoritetaan identifioimalla mahdollisia toteutuksia ohjelmistokonttien väliselle kommunikaatiolle ja ohjelmistokonttien verkottamiselle sekä mittaamalla näiden toteutuksien suorituskyky. Tässä diplomityössä ehdotetaan tutkittavaksi kaksi toteutusta ohjelmistokonttien väliselle kommunikaatiolle ja ohjelmistokonttien verkottamiselle. Nämä toteutukset arvioitiin välityskyvyn (throughput) ja latenssin suhteen. Näiden toteutuksien todettiin olevan soveliaita käytettäväksi pilviradioliityntäverkon käyttäjätason applikaatioissa. Kuitenkin, koska mittaukset toteutettiin yksinkertaistetussa ympäristössä, vaatii toteutuksien implementointi pilviradioliityntäverkon komponenttiin lisätyötä

A complete and efficient CUDA-sharing solution for HPC clusters

In this paper we detail the key features, architectural design, and implementation of rCUDA, an advanced framework to enable remote and transparent GPGPU acceleration in HPC clusters. rCUDA allows decoupling GPUs from nodes, forming pools of shared accelerators, which brings enhanced flexibility to cluster configurations. This opens the door to configurations with fewer accelerators than nodes, as well as permits a single node to exploit the whole set of GPUs installed in the cluster. In our proposal, CUDA applications can seamlessly interact with any GPU in the cluster, independently of its physical location. Thus, GPUs can be either distributed among compute nodes or concentrated in dedicated GPGPU servers, depending on the cluster administrator’s policy. This proposal leads to savings not only in space but also in energy, acquisition, and maintenance costs. The performance evaluation in this paper with a series of benchmarks and a production application clearly demonstrates the viability of this proposal. Concretely, experiments with the matrix–matrix product reveal excellent performance compared with regular executions on the local GPU; on a much more complex application, the GPU-accelerated LAMMPS, we attain up to 11x speedup employing 8 remote accelerators from a single node with respect to a 12-core CPU-only execution. GPGPU service interaction in compute nodes, remote acceleration in dedicated GPGPU servers, and data transfer performance of similar GPU virtualization frameworks are also evaluated. 2014 Elsevier B.V. All rights reserved.This work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO) and by FEDER funds under Grant TIN2012-38341-004-01. It was also supported by MINECO, FEDER funds, under Grant TIN2011-23283, and by the Fundacion Caixa-Castello Bancaixa, Grant P11B2013-21. This work was also supported in part by the U.S. Department of Energy, Office of Science, under contract DE-AC02-06CH11357. Authors are grateful for the generous support provided by Mellanox Technologies to the rCUDA Project. The authors would also like to thank Adrian Castello, member of The rCUDA Development Team, for his hard work on rCUDA.Peña Monferrer, AJ.; Reaño González, C.; Silla Jiménez, F.; Mayo Gual, R.; Quintana-Orti, ES.; Duato Marín, JF. (2014). A complete and efficient CUDA-sharing solution for HPC clusters. Parallel Computing. 40(10):574-588. https://doi.org/10.1016/j.parco.2014.09.011S574588401

Leveraging the Cloud for Integrated Network Experimentation

The goal of this research is to determine the feasibility of performing integrated network experimentation using cloud services. This research uses performance metrics to compare computing architectures constructed in the cloud to architectures that run on traditional networks. If so, then cloud network architectures will display the same expected behavior as traditional network architectures, thus allowing the construction of networking testbeds at potentially substantial cost savings. Since the Amazon cloud does not support broadcast or multicast traffic, distributed applications face a challenge. Many distributed applications use broadcast or multicast to communicate real-time information. This research includes a case study for developing a distributed network application in the cloud which overcomes the restriction on broadcast and multicast traffic. During performance testing, the baseline network and cloud network configurations are provided statistically equivalent traffic workload. Metrics such as packet loss, delay, jitter and throughput are compared to determine relative performance. Analysis of the experimental results shows that in each case, the cloud network configurations performed at or above the performance level of the baseline network. Therefore, the public cloud infrastructure is suitable for performing integrated network experimentation. This research continues Project Everest\u27s efforts to leverage cloud services for network experimentation. Project Everest is a framework which aims to combine emulation and cloud infrastructure into a single testbed using the Amazon Elastic Compute Cloud (EC2). Their tests indicate satisfactory cloud performance, but they recommend testing cloud network performance under various workload. This research carries out those performance tests

Live migration of user environments across wide area networks

A complex challenge in mobile computing is to allow the user to migrate her highly customised environment while moving to a different location and to continue work without interruption. I motivate why this is a highly desirable capability and conduct a survey of the current approaches towards this goal and explain their limitations. I then propose a new architecture to support user mobility by live migration of a user’s operating system instance over the network. Previous work includes the Collective and Internet Suspend/Resume projects that have addressed migration of a user’s environment by suspending the running state and resuming it at a later time. In contrast to previous work, this work addresses live migration of a user’s operating system instance across wide area links. Live migration is done by performing most of the migration while the operating system is still running, achieving very little downtime and preserving all network connectivity. I developed an initial proof of concept of this solution. It relies on migrating whole operating systems using the Xen virtual machine and provides a way to perform live migration of persistent storage as well as the network connections across subnets. These challenges have not been addressed previously in this scenario. In a virtual machine environment, persistent storage is provided by virtual block devices. The architecture supports decentralized virtual block device replication across wide area network links, as well as migrating network connection across subnetworks using the Host Identity Protocol. The proposed architecture is compared against existing solutions and an initial performance evaluation of the prototype implementation is presented, showing that such a solution is a promising step towards true seamless mobility of fully fledged computing environments