Alternative Solutions for Distributed Simulation Cloning

Abstract

Simulation cloning is designed to satisfy the requirement of examining alternative scenarios concurrently. This article discusses the issues involved in cloning distributed simulations based on the High Level Architecture (HLA) and proposes tentative solutions. Alternative solutions are compared from both the qualitative and quantitative point of view. In terms of federation organization, candidate solutions can be classified into the single-federation and the multiple-federation categories. To guarantee the correctness and optimize the performance of the whole cloning-enabled distributed simulation, the single-federation solution requires an additional mechanism to isolate the interactions among alternative executions. Data distribution management (DDM) is one of the candidate approaches. To measure the trade-off between complexity and efficiency, the authors introduce a series of experiments to benchmark various solutions at the runtime infrastructure (RTI) level. The benchmark results indicate that the single-federation solution provides encouraging performance when using DDM.

Concurrent Replication of Parallel and Distributed Simulations

“…The cloning approach includes the management of different time axes in parallel, in order to support a runtime forecasting functionality [24]. In [6] the aim to support users willing to run existing complex simulation models, gave to reusability and transparency issues a top role while enabling simulation cloning. This is the reason for cloning design on HLA-compliant distributed simulations, which led to the introduction of the concept of virtual federates [6,18].…”

“…In [6] the aim to support users willing to run existing complex simulation models, gave to reusability and transparency issues a top role while enabling simulation cloning. This is the reason for cloning design on HLA-compliant distributed simulations, which led to the introduction of the concept of virtual federates [6,18]. A preliminary discussion of the design and implementation challenges and solutions, like virtual logical processes (VLPs) and virtual messages (VMs), can be found in [6,18].…”

“…This is the reason for cloning design on HLA-compliant distributed simulations, which led to the introduction of the concept of virtual federates [6,18]. A preliminary discussion of the design and implementation challenges and solutions, like virtual logical processes (VLPs) and virtual messages (VMs), can be found in [6,18]. The design and implementation of runtime support for cloning of HLAbased parallel and distributed simulations is quite complex and challenging effort.…”

“…The CR-PADS is intended as a way to maximize the speedup and utilization of system resources when implementing a set of parallel and distributed simulations of complex dynamic system models. This approach is substantially different from the simulation Cloning concept [6,18]. Simulation cloning has been demonstrated as a good technique for supporting "faster than real time" simulation [18] and "what if" analysis [6] being based on the active cloning of multiple instances of the initial simulation process at "decision points" that may be met during the simulation.…”

“…This approach is substantially different from the simulation Cloning concept [6,18]. Simulation cloning has been demonstrated as a good technique for supporting "faster than real time" simulation [18] and "what if" analysis [6] being based on the active cloning of multiple instances of the initial simulation process at "decision points" that may be met during the simulation. The CR-PADS approach is not intended as a way to investigate all the possible evolutions from a "decision point", like in the Cloning approach.…”