IoT devices trigger real-time applications by receiving data from their vicinity. Modeling these applications in the form of workflows enables automating their procedure, especially for the business and industry. Depending on the features of the applications, they can be modeled in different forms, including single workflow, multiple workflows, and workflow ensembles. Since the whole data must be sent to the cloud servers for processing and storage, cloud computing has many challenges for executing real-time applications, such as bandwidth limitation, delay, and privacy. Edge paradigms are introduced to address the challenges of cloud computing in executing IoT applications. Executing IoT applications using device-to-device communications in edge paradigms requiring direct communication between devices in a network with a graph topology. While there is no simulator supporting simulating workflow-based applications and device-to-device communication, this paper introduces a toolkit for simulating resource management of scientific workflows in distributed environments with graph topology called WIDESim.The graph topology of WIDESim enables D2D communications in edge paradigms. WIDESim can work with all three different structures of scientific workflows: single, multiple workflows, and workflow ensembles. It has no constraint on the topology of the distributed environment. Also, unlike most existing network simulators, this simulator enables dynamic resource management and scheduling. We have validated the performance of WIDESim in comparison to standard simulators and workflow management tools. Also, we have evaluated its performance in different scenarios of distributed computing systems using different types of workflow-based applications. The results indicate that WIDESim's performance is close to existing standard simulators besides its improvements.

翻译：物联网设备通过接收周边数据触发实时应用。将此类应用以工作流形式建模可实现流程自动化，尤其适用于商业与工业领域。根据应用特征，其可被建模为单工作流、多工作流及工作流集合等多种形式。由于所有数据需传输至云服务器进行处理与存储，云计算在执行实时应用时面临带宽限制、延迟和隐私等诸多挑战。为应对云计算在物联网应用执行中的挑战，边缘计算范式应运而生。在边缘计算范式中，利用设备到设备通信执行物联网应用需要网络中的设备以图拓扑结构进行直接通信。目前尚无模拟器支持基于工作流的应用与设备到设备通信的联合仿真，为此本文提出一种名为WIDESim的工具包，用于模拟图拓扑分布式环境下科学工作流的资源管理。WIDESim的图拓扑特性使其能够支持边缘计算范式中的D2D通信，兼容单工作流、多工作流及工作流集合三种科学工作流结构，且对分布式环境拓扑无约束限制。与现有大多数网络模拟器不同，该模拟器支持动态资源管理与调度。我们通过标准模拟器和工作流管理工具对比验证了WIDESim的性能，并在分布式计算系统的不同场景中使用多种基于工作流的应用进行了性能评估。结果表明，WIDESim在保持功能改进的同时，其性能接近现有标准模拟器。