SUMMARY

Cloud computing allows the deployment and delivery of application services for users worldwide. Software as a Service providers with limited upfront budget can take advantage of Cloud computing and lease the required capacity in a pay-as-you-go basis, which also enables flexible and dynamic resource allocation according to service demand. One key challenge potential Cloud customers have before renting resources is to know how their services will behave in a set of resources and the costs involved when growing and shrinking their resource pool. Most of the studies in this area rely on simulation-based experiments, which consider simplified modeling of applications and computing environment. In order to better predict service's behavior on Cloud platforms, we developed an integrated architecture that is based on both simulation and emulation. The proposed architecture, named EMUSIM, automatically extracts information from application behavior via emulation and then uses this information to generate the corresponding simulation model. We performed experiments using an image processing application as a case study and found that EMUSIM was able to accurately model such application via emulation and use the model to supply information about its potential performance in a Cloud provider. We also discuss our experience using EMUSIM for deploying applications in a real public Cloud provider. EMUSIM is based on an open source software stack and therefore it can be extended for analysis behavior of several other applications. Copyright © 2012 John Wiley & Sons, Ltd.

EMUSIM: an integrated emulation and simulation environment for modeling, evaluation, and validation of performance of Cloud computing applications

The ability to establish an objective comparison between high-performance TCP variants under diverse networking conditions and to obtain a quantitative assessment of their impact on the global network traffic is essential to a community-wide understanding of various design approaches. Small-scale experiments are insufficient for a comprehensive study of these TCP variants. We propose a TCP performance evaluation testbed, called SVEET, on which real implementations of the TCP variants can be accurately evaluated under diverse network configurations and workloads in large-scale network settings. This testbed combines real-time immersive simulation, emulation, machine and time virtualization techniques. We validate the testbed via extensive experiments and assess its capabilities through case studies involving real web services.

SVEET! a scalable virtualized evaluation environment for TCP

Following ten years of experience using the Scalable Simulation Framework (SSF), we revisited its API, making changes to better reflect use and support maintainability. This paper gives a quick overview of SSF, and discusses changes made in the second-generation API, S3F. Of particular interest is S3F's treatment of advancing time (in epochs), its treatment of "processes", and the support it gives the modeler over precise ordering of events that happen to be scheduled at the same simulation time.

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S3F: the Scalable Simulation Framework revisited

Real-time network simulation refers to simulating computer networks in real time so that the virtual network can interact with real implementations of network protocols, network services, and distributed applications. In this paper, we present the motivation behind real-time network simulation and compare it against other major networking research tools, including analytical models, physical testbeds, simulation, and emulation. We introduce PRIME, a parallel real-time network simulator, and provide a summary of techniques that allow PRIME to model large-scale networks and interact with many real applications under the real-time constraint. We also discuss ongoing research efforts that will allow real-time network simulation to assume important roles at supporting future networking research.

A Primer for Real-Time Simulation of Large-Scale Networks

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S3F: The Scalable Simulation Framework revisited

We present a software infrastructure that embeds physical hosts in a simulated network. Aiming to create a large-scale real-time virtual network testbed, our real-time interactive simulation approach combines the advantages of both simulation and emulation, by maintaining flexibility of the simulation models and increasing fidelity as real systems are included in the simulation. In our approach, real-world distributed applications and network services can run together with the real-time simulator; real packets are injected into the simulation and subject to the simulated network conditions computed as a result of both real and virtual traffic competing for network resources. A prototype of the proposed emulation infrastructure has been implemented based on virtual private network (VPN). One distinct advantage of our approach is that it does not require special hardware. Furthermore, it is flexible, secure, and scalable-attributes inherited directly from the VPN implementation. We conducted a set of preliminary experiments to assess the performance limitations of our emulation infrastructure. We also present an interesting case study to demonstrate the capability of our approach.

S. Mann

Papers

An Open and Scalable Emulation Infrastructure for Large-Scale Real-Time Network Simulations