Event-driven SOA

Abstract: Event-driven architecture is gaining momentum in research and application areas as it promises enhanced responsiveness and asynchronous communication. The combination of event-driven and service-oriented architectural paradigms and web service technologies provide a viable possibility to achieve these promises. This paper outlines an architectural design and accompanying implementation technologies for its realization as a web services-based event-driven SOA.

Abstract: Although lots of IoT (Internet of Things) applications have been developed, the systematic method to construct IoT services is still obscure. In this paper, an Event-driven Service-oriented Architecture (EDSOA) for IoT services is discussed, where distributed events act as a primary mechanism for each IoT service to share independent meaningful events, to express its requirements and capabilities, and to decouple itself from other services. Such distributed events however do not provide powerful expressiveness to describe business logic in SOA because business activities are not completely independent each other. To fill the gap, we propose an information-centric session mechanism to describe service behavior working upon distributed events, called event session. This paper also discusses how to build an Event-driven SOA infrastructure, where we can use resource information to create IoT services, use independent and shared events to run the IoT services, and use event session to coordinate the IoT services. Some applications and experiments are given to show concept proof for such event-driven SOA.

Abstract: In order to build a low-latency lightweight publish/subscribe (pub/sub) system for IOT services, we propose an efficient and scalable broker architecture, called Grid Quorum-based pub/sub system (GQPS). As a core component in the event-driven SOA framework for IOT services, this architecture organizes multiple pub/sub brokers into a quorum-based peer-to-peer topology for efficient topic searching. It also leverages a topic searching algorithm and a caching strategy to achieve a small and constant search latency. Lightweight RESTful interfaces make our GQPS more suitable for IOT services. Cost analysis and experiment study demonstrate that GQPS achieves a significant performance gain in search satisfaction without compromising search cost. We applied GQPS in the District Heating Control and Information Service System in Beijing, China, which validates the feasibility and availability of our architecture.

Abstract: Due to the increasing threat posed by crime, industrial espionage and even terrorism, video surveillance systems have become more important and powerful during the last years. While most commercially available surveillance systems have to be managed by human operators, who constantly monitor all video streams, several experimental systems from different research groups already include robust video processing approaches for (semi-) automated surveillance. Still, most research activities focus on a sensororiented approach to video analytics of large and distributed camera networks, aiming to extract, analyze and store all extractable information from the video streams. In real-life applications, however, only a limited set of specific threats needs to be covered. Accordingly, only a small subset of potentially extractable information has to be monitored. Besides the huge amount of raw video data, modern surveillance systems are also extended with other sensors that deliver even more data. As a consequence, a new paradigm is introduced, called task-oriented information and data processing for surveillance systems. In the proposed system NEST (Network Enabled Surveillance and Tracking) following the task-oriented approach, every resource allocation, data acquisition, and analysis process is assigned to a specific surveillance task. In order to meet the requirements of taskoriented surveillance, the proposed architecture combines a Service-Oriented Architecture with an Event-Driven Architecture (Event-driven SOA).