Time Jails: A Hybrid Approach to Scalable Network Emulation

It is essential to evaluate the performance of newly developed distributed software and network protocols. Network emulation enables reproducible evaluation of unmodified real implementations. Software built for distributed systems, such as a large scale peer-to-peer system, requires evaluation scenarios with thousands of communicating nodes. Two approaches for scaling network emulation to such scenario sizes have been proposed in the literature: node virtualization and time visualization. Node visualization allows maximizing the utilization of standard hardware used for emulation experiments. Time visualization enables trading experiment duration for visually increased resources of the hardware. It stands to reason that a combination of those two approaches may increase scalability even further. However, in existing combinations, either node visualization implies relatively high overhead or time virtualization requires modifications of the test subject implementation. In this paper, we present a novel hybrid approach called time visualized emulation environment (TVEE). It integrates node visualization with low overhead and time virtualization, which is transparent to the execution of test subjects. We introduce visual time based on epochs to enable better dynamic hardware utilization during long lasting experiments. Additionally, a mechanism similar to soft timers ensures an accurate reproduction of network properties in the time visualized emulation. Our evaluations show the accuracy and scalability of time visualized network emulation. Comparing TCP throughput, TVEE outperforms other approaches using an event based visual time by an order of magnitude.

[1]  Robert N. M. Watson,et al.  Jails: confining the omnipotent root , 2000 .

[2]  George Apostolopoulos,et al.  V-eM: A Cluster of Virtual Machines for Robust, Detailed, and High-Performance Network Emulation , 2006, 14th IEEE International Symposium on Modeling, Analysis, and Simulation.

[3]  Brian W. Unger,et al.  Towards scalable network emulation , 2001, SPIE ITCom.

[4]  Kurt Rothermel,et al.  Scalable Network Emulation: A Comparison of Virtual Routing and Virtual Machines , 2007, 2007 12th IEEE Symposium on Computers and Communications.

[5]  Mostafa H. Ammar,et al.  A generic framework for parallelization of network simulations , 1999, MASCOTS '99. Proceedings of the Seventh International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems.

[6]  R. M. Fujimoto,et al.  Parallel discrete event simulation , 1989, WSC '89.

[7]  P. Druschel,et al.  Soft timers: efficient microsecond software timer support for network processing , 2000, OPSR.

[8]  Shigeru Chiba,et al.  Secure and manageable virtual private networks for end-users , 2003, 28th Annual IEEE International Conference on Local Computer Networks, 2003. LCN '03. Proceedings..

[9]  Srinidhi Varadarajan,et al.  The Distributed Open Network Emulator: Using Relativistic Time for Distributed Scalable Simulation , 2006, 20th Workshop on Principles of Advanced and Distributed Simulation (PADS'06).

[10]  Amin Vahdat,et al.  To infinity and beyond: time warped network emulation , 2005, SOSP '05.

[11]  H. T. Kung,et al.  A new methodology for easily constructing extensible and high-fidelity TCP/IP network simulators , 2002, Comput. Networks.

[12]  Peter A. Dinda,et al.  The statistical properties of host load , 1999, Sci. Program..

[13]  Richard Wolski,et al.  Implementing a Performance Forecasting System for Metacomputing The Network Weather Service , 1997, ACM/IEEE SC 1997 Conference (SC'97).

[14]  Brian W. Unger,et al.  Improving scalability of network emulation through parallelism and abstraction , 2005, 38th Annual Simulation Symposium.

[15]  Mike Hibler,et al.  Feedback-directed Virtualization Techniques for Scalable Network Experimentation , 2004 .