Experiences in messaging middle-ware for high-level control applications

Existing high-level applications in accelerator control and modeling systems leverage many different languages, tools and frameworks that do not inter-operate with one another. As a result, the accelerator control community is moving toward the proven Service-Oriented Architecture (SOA) approach to address the inter-operability challenges among heterogeneous high-level application modules. Such SOA approach enables developers to package various control subsystems and activities into 'services' with well-defined 'interfaces' and make leveraging heterogeneous high-level applications via flexible composition possible. Examples of such applications include presentation panel clients based on Control System Studio (CSS) and middle-layer applications such as model/data servers. This paper presents our experiences in developing a demonstrative high-level application environment using emerging messaging middle-ware standards. In particular, we utilize new features in EPICS v4 and other emerging standards such as Data Distribution Service (DDS) and Extensible Type Interface by the Object Management Group. We first briefly review examples we developed previously. We then present our current effort in integrating DDS into such a SOA environment for control systems. Specifically, we illustrate how we are integrating DDS into CSS and develop a Python DDS mapping. (authors)