The new CERN Controls Middleware

The Controls Middleware (CMW) project was launched over ten years ago. Its main goal was to unify middleware solutions used to operate the CERN accelerator complex. A key part of the project, the equipment access library RDA, was based on CORBA, an unquestionable middleware standard at the time. RDA became an operational and critical part of the infrastructure, yet the demanding run-time environment revealed shortcomings of the system. Accumulation of fixes and workarounds led to unnecessary complexity. RDA became difficult to maintain and to extend. CORBA proved to be rather a cumbersome product than a panacea. Fortunately, many new transport frameworks appeared since then. They boasted a better design and supported concepts that made them easier to use. Willing to profit from the coming long LHC shutdown which will make it possible to update the operational software, the CMW team reviewed user requirements and in their terms investigated eventual CORBA substitutes. Evaluation of several market recognized products helped to identify the most-suitable middleware solution: ZeroMQ. This article presents the results of the evaluation process, the proposed design and functionality of the new system as well as the plan of its integration with the currently deployed system.