Fog computing is envisioned to enable profound applications in the Internet of Things (IoT). A key characteristic of such applications is the need to exchange vital information between distinct IoT devices in the form of event notifications, e. g., traffic conditions when performing traffic monitoring. Complex event processing (CEP) is a powerful paradigm to overcome the information gap from observing primary sensor data by IoT devices to delivering event notifications to the IoT application users. However, to perform CEP in a highly dynamic IoT environment, e. g., involving mobile and heterogeneous devices, require an extremely flexible design of a CEP system to adaptively meet the changing requirements and conditions in which the CEP system is executed.In this article, we show on the use case of CEP, “how to increase flexibility in a fog-cloud computing environment building on a methodology known as mechanism transitions”. In particular, we state and analyze two exemplary IoT use cases to show the potential of mechanism transitions. We identify and discuss possible promising mechanism transitions in the context of CEP. We perform an experimental study for operator placement and show how transitions help to adapt to conflicting performance objectives.

中文翻译：

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提升雾计算灵活性的过渡：复杂事件处理的案例研究

雾计算可以实现物联网（IoT）中的广泛应用。此类应用程序的关键特征是需要以事件通知的形式在不同的IoT设备之间交换重要信息，例如 例如，进行交通监控时的交通状况。复杂事件处理（CEP）是一种强大的范例，可以克服从IoT设备观察主要传感器数据到向IoT应用程序用户传递事件通知的信息鸿沟。但是，要在高度动态的物联网环境中执行CEP，例如 例如，涉及移动设备和异构设备的CEP，要求CEP系统的设计非常灵活，以适应在执行CEP系统时不断变化的要求和条件。在本文中，我们展示了CEP的用例，机制转变”。特别是，我们陈述并分析了两个示例性IoT用例，以显示机制转换的潜力。我们确定并讨论了在CEP中可能出现的有希望的机制过渡。我们对操作员的位置进行了实验研究，并显示了过渡如何帮助适应冲突的性能目标。