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


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.


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]

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.
author={R. Rong and J. Liu},
booktitle={2017 IEEE International Conference on Communications (ICC)},
title={Distributed mininet with symbiosis},