To address these limitations, we propose EASE, a next generation multi-tenant infrastructure emulator with an aim to maximize hardware utilization while providing performance guarantee, isolation and full-fledged support for SDN and NFV. On the other hand, acquisition of virtualized instances lack guarantee and isolation resulting in an unrealistic emulation outcome. Acquisition of physical instances provides performance guarantee and isolation, but compromises overall system utilization. However, these testbeds do not provide performance guarantee.
There are several publicly available testbeds such as Emulab, GENI or OFELIA that allow users to lease physical and virtual resources for emulation. Bugs or misconfiguration can cause service outage and trigger customer churn along with loss of reputation. It is very difficult to determine the behavior of a new application or service without deploying it in the production environment. A similar problem is faced by network operators when they want to introduce a new service in their production network. However, service providers still need to own an infrastructure to test their applications or services. In the last decade we have observed a tremendous adoption of distributed applications and a trend to host services in private or public clouds. Our adaptive time dilation dynamically controls the time dilation factor to avoid system overloads for both the simulation and the emulation components and to improve the execution correctness of the hybrid system. Our approach uses time dilation to reduce simulation delays and thus increasing the accuracy of the integrated simulation and emulation system. However, a heavily-loaded simulator can introduce significant simulation delays and thereby create situations where these delays impact the accuracy of the system. If a simulator schedules its events in real time and the simulation time keeps up with the real time, then the hybrid system works very well and meets its deadlines.
In this paper, we propose integrating simulation with emulation using adaptive time dilation to evaluate system performance. A hybrid approach in which simulation nodes connect to emulation hosts can be used to combine the advantages of both approaches. In contrast, emulation does not need to re-implement the target real systems, so it may improve on the implementation efficiency of simulation while maintaining much of the realism of testbeds. Simulation conveniently predicts the behavior of a complex networked system while usually requiring fewer simplifying model assumptions often necessary for theoretical analysis.
Simulation and emulation techniques are commonly used to evaluate the performance of complex networked systems.
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