Talk: Virtual Time Machine for Reproducibility

Virtual Time Machine for Large-Scale Reproducible Distributed Emulation

2017 GEFI Workshop
Rio de Janeiro, Brazil
October 26, 2017

Abstract

Cyber-infrastructure and meta-cloud testbeds, such as GENI, CloudLab, and Chameleon, are shared facilities that can be configured to provide a diverse and yet controllable environment for testing network protocols and distributed applications. Combined with emulation capabilities, these testbeds provide automated tools for allocating resources, instantiating applications, and collecting measurements. To facilitate reproducibility, they provide support for re-creating the execution environment between experiment runs. A major issue, however, with reproducibility on these systems is the lack of accurate control of time, especially when the experiment faces resource oversubscription. Virtual time management has been proposed for scheduling time dilated virtual machines to increase time fidelity. We hereby propose a unified resource and time scheme on cyber-infrastructure and meta-cloud testbeds to enable large-scale, high-capacity, high-fidelity, reproducible distributed emulation.

Slides

Invited Talk: Faster and Better Hybrid Testbeds for Future Network Research

Faster and Better Hybrid Testbeds for Future Network Research

June 1, 2017

Future Network Theory and Application Laboratory (FNL)
Beijing University of Posts and Telecommunications, Beijing, China
Host: Professor Tao Huang (黄韬)

Abstract: Modeling and simulation (M&S) plays an important role in the design analysis and performance evaluation of computer networks. The ability to execute large-scale simulation on high-end computing systems has enabled us to model detailed and complex network behaviors. However, the difficulty in reproducing realistic large-scale network phenomena goes beyond designing efficient parallel algorithms. This talk will cover some of the recent high-performance network modeling and simulation techniques, particularly in the context of developing testbeds for future network research. We will focus specifically on our recent research in real-time simulation, hybrid network traffic modeling, and symbiotic simulation and emulation.

Invited Talk: High-Performance Modeling and Simulation of Computer Networks

High-Performance Modeling and Simulation of Computer Networks

May 26, 2017

Department of Computer Science
Tsinghua University, Beijing, China
Host: Professor Zhihui Du (都志辉)

Abstract: Modeling and simulation (M&S) plays an important role in the design analysis and performance evaluation of complex systems. Many of these systems, such as computer networks, involve a large number of interrelated components and processes. Complex behaviors emerge as these components and processes inter-operate across multiple scales at various granularities. M&S must be able to provide sufficiently accurate results while coping with the scale and complexity.

My talk will focus on two novel techniques in high-performance network modeling and simulation. The first is a GPU-assisted hybrid network traffic modeling method. The hybrid approach offloads the computationally intensive bulk traffic calculations to the background onto GPU, while leaving detailed simulation of network transactions in the foreground on CPU. Our experiments show that the CPU-GPU hybrid approach can achieve significant performance improvement over the CPU-only approach.

The second technique is a distributed network emulation method based on simulation symbiosis. Mininet is a container-based emulation environment that can study networks consisted of virtual hosts and OpenFlow-enabled virtual switches on Linux. It is well-known, however, that experiments using Mininet may lose fidelity for large-scale networks and heavy traffic load. The proposed symbiotic approach uses an abstract network model to coordinate distributed Mininet instances with superimposed traffic to represent large-scale network scenarios.

ICC’17 Paper: Mininet Symbiosis

Distributed Mininet with Symbiosis, Rong Rong and Jason Liu. In Proceedings of the IEEE International Conference on Communications (ICC 2017), May 2017.  [paper]

abstractbibtexslides
Mininet is a container-based emulation environment that can study networks with virtual hosts and OpenFlow- enabled virtual switches on Linux. However, it is well-known that experiments using Mininet may lose fidelity for large- scale networks and heavy traffic load. One solution is to use a distributed setup where an experiment constitutes multiple instances of Mininet running on a cluster, each handling a subset of virtual hosts and switches. Such arrangement, however, is still constrained by bandwidth and latency limitations in the physical connection between the instances. In this paper, we propose a novel method of integrating distributed Mininet instances using a symbiotic approach, which extends an existing method for combining real-time simulation and emulation. We use an abstract network model to coordinate the distributed instances, which are superimposed to represent the target network. In this case, one can more effectively study the behavior of real imple- mentation of network applications on large-scale networks, since the interaction between the Mininet instances is only capturing the effect of contentions among network flows in shared queues, as opposed to having to exchange individual network packets, which can be limited by bandwidth or sensitive to latency. We provide a prototype implementation of the new approach and present validation studies to show it can achieve accurate results. We also present a case study that successfully replicates the behavior of a denial-of-service (DoS) attack protocol.
@INPROCEEDINGS{rong2017-symbiosis,
author={R. Rong and J. Liu},
booktitle={2017 IEEE International Conference on Communications (ICC)},
title={Distributed mininet with symbiosis},
year={2017},
pages={1-6},
doi={10.1109/ICC.2017.7996343},
month={May},}

Invited Talk: High-Performance Modeling and Simulation of Computer Networks

High-Performance Modeling and Simulation of Computer Networks

April 26, 2017

Laboratory of Information, Networking and Communication Sciences (LINCS), Paris, France
Host: Professor Dario Rossi

Abstract: Modeling and simulation (M&S) plays an important role in the design analysis and performance evaluation of complex systems. Many of these systems, such as computer networks, involve a large number of interrelated components and processes. Complex behaviors emerge as these components and processes inter-operate across multiple scales at various granularities. M&S must be able to provide sufficiently accurate results while coping with the scale and complexity.
My talk will focus on two novel techniques in high-performance network modeling and simulation. The first is a GPU-assisted hybrid network traffic modeling method. The hybrid approach offloads the computationally intensive bulk traffic calculations to the background onto GPU, while leaving detailed simulation of network transactions in the foreground on CPU. Our experiments show that the CPU-GPU hybrid approach can achieve significant performance improvement over the CPU-only approach.
The second technique is a distributed network emulation method based on simulation symbiosis. Mininet is a container-based emulation environment that can study networks consisted of virtual hosts and OpenFlow-enabled virtual switches on Linux. It is well-known, however, that experiments using Mininet may lose fidelity for large-scale networks and heavy traffic load. The proposed symbiotic approach uses an abstract network model to coordinate distributed Mininet instances with superimposed traffic to represent large-scale network scenarios.

Invited Talk: Extending PrimoGENI for Symbiotic Distributed Network Emulation

Extending PrimoGENI for Symbiotic Distributed Network Emulation

March 13, 2017

GENI Regional Workshop (GRW), held in conjunction with GEC25 Miami, Florida, USA

The talk includes recent development in hybrid at-scale network experimentation, which extends the previous PrimoGENI project.

[slides]

Invited Talk: Symbiotic Modeling and High-Performance Simulation

Symbiotic Modeling and High-Performance Simulation

January 19, 2017

Department of Computer Science, Colorado School of Mines
Host: Professor Tracy Camp

Abstract: Modeling and simulation plays an important role in the design analysis and performance evaluation of complex systems. Many of these systems, such as the internet and high-performance computing systems, involve a huge number of interrelated components and processes. Complex behaviors emerge as these components and processes inter-operate across multiple scales at various granularities. Modeling and simulation must be able to provide sufficiently accurate results while coping with the scale and the complexity of these systems. My talk will focus on some of our latest advances in high-performance modeling and simulation techniques. I will focus on two specific case studies, one on network emulation and the other on high-performance computing (HPC) modeling.
In the first case, I will present a novel distributed network emulation mechanism based on modeling symbiosis. Mininet is a container-based emulation environment that can study networks consisted of virtual hosts and OpenFlow-enabled virtual switches on Linux. It is well-known, however, that experiments using Mininet may lose fidelity for large-scale networks and heavy traffic load. We propose a symbiotic approach, where an abstract network model is used to coordinate the distributed emulation instances superimposed to represent the target network. In doing so, we can effectively study the behavior of real implementation of network applications on large-scale networks in a distributed environment.
In the second case, I will present our latest work on performance modeling of HPC architectures and applications. In collaboration with the Los Alamos National Laboratory, we have developed a highly efficient simulator, called Performance Prediction Toolkit (PPT), which can facilitate rapid and accurate performance prediction of large-scale scientific applications on existing and future HPC architectures.

TOMACS’15 Paper: Symbiotic Network Simulation and Emulation

Symbiotic Network Simulation and Emulation, Miguel Erazo, Rong Rong, and Jason Liu. ACM Transactions on Modeling and Computer Simulation (TOMACS), 26(1), Article No. 2, December 2015. [paper]

abstractbibtex
A testbed capable of representing detailed operations of complex applications under diverse network conditions is invaluable for understanding the design and performance of new protocols and applications before their real deployment. We introduce a novel method that combines high-performance large-scale network simulation and high-fidelity network emulation, and thus enables real instances of network applications and protocols to run in real operating environments and be tested under simulated network settings. Using our approach, network simulation and emulation can form a symbiotic relationship, through which they are synchronized for an accurate representation of the network-scale traffic behavior. We introduce a model downscaling method along with an efficient queuing model and a traffic reproduction technique, which can significantly reduce the synchronization overhead and improve accuracy. We validate our approach with extensive experiments via simulation and with a real-system implementation. We also present a case study using our approach to evaluate a multipath data transport protocol.
@article{Erazo2015:symbiosis,
author = {Erazo, Miguel A. and Rong, Rong and Liu, Jason},
title = {Symbiotic Network Simulation and Emulation},
journal = {ACM Trans. Model. Comput. Simul.},
issue_date = {December 2015},
volume = {26},
number = {1},
month = jun,
year = {2015},
issn = {1049-3301},
pages = {2:1–2:25},
articleno = {2},
numpages = {25},
url = {http://doi.acm.org/10.1145/2717308},
doi = {10.1145/2717308},
acmid = {2717308},
publisher = {ACM},
address = {New York, NY, USA},
}

DSRT’15 Paper: Scalable Emulation with Simulation Symbiosis

Toward Scalable Emulation of Future Internet Applications with Simulation Symbiosis, Jason Liu, Cesar Marcondes, Musa Ahmed, and Rong Rong. In Proceedings of the 19th IEEE/ACM International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2015), October 2015. [paper]

abstractbibtex
Mininet is a popular container-based emulation environment built on Linux for testing OpenFlow applications. Using Mininet, one can compose an experimental network using a set of virtual hosts and virtual switches with flexibility. However, it is well understood that Mininet can only provide a limited capacity, both for CPU and network I/O, due to its underlying physical constraints. We propose a method for combining simulation and emulation to improve the scalability of network experiments. This is achieved by applying the symbiotic approach to effectively integrate emulation and simulation for hybrid experimentation. In this case, one can use Mininet to directly run OpenFlow applications on the virtual machines and software switches, with network connectivity represented by detailed simulation at scale.
@INPROCEEDINGS{Liu2015:emulation-symbiosis,
author={J. Liu and C. Marcondes and M. Ahmed and R. Rong},
booktitle={Proccedings of the 2015 IEEE/ACM 19th International Symposium on Distributed Simulation and Real Time Applications (DS-RT)},
title={Toward Scalable Emulation of Future Internet Applications with Simulation Symbiosis},
year={2015},
pages={68-77},
doi={10.1109/DS-RT.2015.19},
ISSN={1550-6525},
month={Oct},
}