Cosylab, Ljubljana
Accelerators are designed to be in operation for several decades, and frequently even their construction alone takes a decade or more. Given the rapid rate of obsolescence of information technologies, it becomes a challenge how to choose the technologies that would stand the test of time, or at least make long-term support manageable. In this article, we focus on middleware: the glue that keeps inherently heterogeneous control system platforms able to interoperate with each another. Modern and less-modern middlewares, such as Internet Communication Environment (ICE), Common Object Request Broker Architecture (CORBA), Microsoft Windows Communications Foundation (WCF) are presented, and contrasted with more domain-specific middleware, such as the Experimental Physics and Industrial Control System (EPICS). We argue that whichever middleware technology is used, it is advisable to abstract it with simple, domain-specific APIs, whose implementation can change as the evolving performance requirements push the initial middleware choice beyond its limits of applicability.
