A Testbed For Validating the LHC Controls System Core Before Deployment

Since the start-up of the LHC, it is crucial to carefully test core controls components before deploying them operationally. The Testbed of the CERN accelerator controls group was developed for this purpose. It contains different hardware (PPC, i386) running various operating systems (Linux and LynxOS) and core software components running on front-ends, communication middleware and client libraries. The Testbed first executes integration tests to verify that the components delivered by individual teams interoperate, and then system tests, which verify high-level, end-user functionality. It also verifies that different versions of components are compatible, which is vital, because not all parts of the operational LHC control system can be upgraded simultaneously. In addition, the Testbed can be used for performance and stress tests. Internally, the Testbed is driven by Atlassian Bamboo, a Continuous Integration server, which builds and deploys automatically new software versions into the Testbed environment and executes the tests continuously to prevent from software regression. Whenever a test fails, an e-mail is sent to the appropriate persons. The Testbed is part of the official Controls System development process wherein new releases of the controls system have to be validated before being deployed operationally. Integration and system tests are an important complement to the unit tests previously executed in the teams. The Testbed has already caught serious bugs that were not discovered by the unit tests of the individual components.