Author: Buttner, M.
Paper Title Page
MOPKN011 CERN Alarms Data Management: State & Improvements 110
  • Z. Zaharieva, M. Buttner
    CERN, Geneva, Switzerland
  The CERN Alarms System - LASER is a centralized service ensuring the capturing, storing and notification of anomalies for the whole accelerator chain, including the technical infrastructure at CERN. The underlying database holds the pre-defined configuration data for the alarm definitions, for the Operators alarms consoles as well as the time-stamped, run-time alarm events, propagated through the Alarms Systems. The article will discuss the current state of the Alarms database and recent improvements that have been introduced. It will look into the data management challenges related to the alarms configuration data that is taken from numerous sources. Specially developed ETL processes must be applied to this data in order to transform it into an appropriate format and load it into the Alarms database. The recorded alarms events together with some additional data, necessary for providing events statistics to users, are transferred to the long-term alarms archive. The article will cover as well the data management challenges related to the recently developed suite of data management interfaces in respect of keeping data consistency between the alarms configuration data coming from external data sources and the data modifications introduced by the end-users.  
poster icon Poster MOPKN011 [4.790 MB]  
FRBHMUST02 Towards High Performance Processing in Modern Java Based Control Systems 1322
  • M. Misiowiec, W. Buczak, M. Buttner
    CERN, Geneva, Switzerland
  CERN controls software is often developed on Java foundation. Some systems carry out a combination of data, network and processor intensive tasks within strict time limits. Hence, there is a demand for high performing, quasi real time solutions. Extensive prototyping of the new CERN monitoring and alarm software required us to address such expectations. The system must handle dozens of thousands of data samples every second, along its three tiers, applying complex computations throughout. To accomplish the goal, a deep understanding of multithreading, memory management and interprocess communication was required. There are unexpected traps hidden behind an excessive use of 64 bit memory or severe impact on the processing flow of modern garbage collectors, including the state of the art Oracle GarbageFirst. Tuning JVM configuration significantly affects the execution of the code. Even more important is the amount of threads and the data structures used between them. Accurately dividing work into independent tasks might boost system performance. Thorough profiling with dedicated tools helped understand the bottlenecks and choose algorithmically optimal solutions. Different virtual machines were tested, in a variety of setups and garbage collection options. The overall work provided for discovering actual hard limits of the whole setup. We present this process of architecting a challenging system in view of the characteristics and limitations of the contemporary Java runtime environment.
slides icon Slides FRBHMUST02 [4.514 MB]