Software Development and Testing: Approach and Challenges in a distributed HEP Collaboration

In developing the ATLAS [1] Trigger and Data Acquisition (TDAQ) software, the team is applying the iterative waterfall model, evolutionary process management, formal software inspection, and lightweight review techniques. The long preparation phase, with a geographically widespread development team required that the standard techniques be adapted to this HEP environment. The testing process is receiving special attention. Unit tests and check targets in nightly project builds form the basis for the subsequent software project release testing. The integrated software is then being run on computing farms that give further opportunites for gaining experience, fault finding, and acquiring ideas for improvement. Dedicated tests on a farm of up to 1000 nodes address the large-scale aspect of the project. Integration test activities on the experimental site include the special purpose-built event readout hardware. Deployment in detector commissioning starts the countdown towards running the final ATLAS experiment. These activities aim at both understanding and completing the complex system, and help in forming a team whose members have a variety of expertise, working cultures, and professional backgrounds

Integration of VICbus, FDL, SCI and Ethernet in the CERN CASCADE data acquisition system

Cascade is a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group. Configurations supported today include VMEbus processors running OS-9 and UNIX workstations. The CASCADE data acquisition processes, called stages communicate via links, at present VICbus between VME crates and Ethernet between VMEbus processors and workstations. Work is in progress to introduce new inter-stage links based on the Fast Data Link between VME crates and on SCI for data exchange between SUN stations. The paper gives a short description of the architecture of CASCADE with emphasis on the link aspects. The implementation and current status of the inter-stage links based on VICbus, Ethernet, FDI, and SCI will be described and results on the performances presented

Review and prospects of the CASCADE data acquisition system at CERN

CASCADE, a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group, has now been in operation for one year. The current implementation supports configurations based on VMEbus processors running OS-9 and on UNIX workstations interconnected via VICbus or Ethernet. The project is reviewed by describing the main characteristics of the package, the applications in which it has been used, and the results of this experience. The main improvements of 1994, which include a parameterized multi-level event builder, a remote monitoring option and a powerful run control facility, as well as ongoing developments and prospects for 1995, are presented

Performance and scalability of the back-end sub-system in the ATLAS DAQ/EF prototype

The DAQ group of the future ATLAS experiment has developed a prototype system based on the trigger/DAQ architecture described in the ATLAS Technical Proposal to support studies of the full system functionality, architecture as well as available hardware and software technologies. One sub-system of this prototype is the back- end which encompasses the software needed to configure, control and monitor the DAQ, but excludes the processing and transportation of physics data. The back-end consists of a number of components including run control, configuration databases and message reporting system. The software has been developed using standard, external software technologies such as OO databases and CORBA. It has been ported to several C++ compilers and operating systems including Solaris, Linux, WNT and LynxOS. This paper gives an overview of the back-end software, its performance, scalability and current status. (17 refs)