CMX - A Generic Solution to Expose Monitoring Metrics in C and C++ Applications

CERN’s Accelerator Control System is built upon a large number of C, C++ and Java services that are required for daily operation of the accelerator complex. The knowledge of the internal state of these processes is essential for problem diagnostic as well as for constant monitoring for pre-failure recognition. The CMX library follows similar principles as JMX (Java Management Extensions) and provides similar monitoring capabilities for C and C++ applications. It allows registering and exposing runtime information as simple counters, floating point numbers or character data. This can be subsequently used by external diagnostics tools for checking thresholds, sending alerts or trending. CMX uses shared memory to ensure non-blocking read/update actions, which is an important requirement in real-time processes. This paper introduces the topic of monitoring C/C++ applications and presents CMX as a building block to achieve this goal.