The CMS data acquisition system software Bauer, G; Behrens, U; Biery, K ...
Journal of physics. Conference series,
04/2010, Letnik:
219, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The CMS data acquisition system is made of two major subsystems: event building and event filter. The presented paper describes the architecture and design of the software that processes the data ...flow in the currently operating experiment. The central DAQ system relies on industry standard networks and processing equipment. Adopting a single software infrastructure in all subsystems of the experiment imposes, however, a number of different requirements. High efficiency and configuration flexibility are among the most important ones. The XDAQ software infrastructure has matured over an eight years development and testing period and has shown to be able to cope well with the requirements of the CMS experiment.
The CMS event builder and storage system Bauer, G; Beccati, B; Behrens, U ...
Journal of physics. Conference series,
04/2010, Letnik:
219, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The CMS event builder assembles events accepted by the first level trigger and makes them available to the high-level trigger. The event builder needs to handle a maximum input rate of 100 kHz and an ...aggregated throughput of 100 GB/s originating from approximately 500 sources. This paper presents the chosen hardware and software architecture. The system consists of 2 stages: an initial pre-assembly reducing the number of fragments by one order of magnitude and a final assembly by several independent readout builder (RU-builder) slices. The RU-builder is based on 3 separate services: the buffering of event fragments during the assembly, the event assembly, and the data flow manager. A further component is responsible for handling events accepted by the high-level trigger: the storage manager (SM) temporarily stores the events on disk at a peak rate of 2 GB/s until they are permanently archived offline. In addition, events and data-quality histograms are served by the SM to online monitoring clients. We discuss the operational experience from the first months of reading out cosmic ray data with the complete CMS detector.
The CMS Data Acquisition cluster, which runs around 10000 applications, is configured dynamically at run time. XML configuration documents determine what applications are executed on each node and ...over what networks these applications communicate. Through this mechanism the DAQ System may be adapted to the required performance, partitioned in order to perform (test-) runs in parallel, or re-structured in case of hardware faults. This paper presents the configuration procedure and the CMS DAQ Configurator tool, which is used to generate comprehensive configurations of the CMS DAQ system based on a high-level description given by the user. Using a database of configuration templates and a database containing a detailed model of hardware modules, data and control links, nodes and the network topology, the tool automatically determines which applications are needed, on which nodes they should run, and over which networks the event traffic will flow. The tool computes application parameters and generates the XML configuration documents and the configuration of the run-control system. The performance of the configuration procedure and the tool as well as operational experience during CMS commissioning and the first LHC runs are discussed.
The CMS data acquisition system comprises O(20000) interdependent services that need to be monitored in near real-time. The ability to monitor a large number of distributed applications accurately ...and effectively is of paramount importance for robust operations. Application monitoring entails the collection of a large number of simple and composed values made available by the software components and hardware devices. A key aspect is that detection of deviations from a specified behaviour is supported in a timely manner, which is a prerequisite in order to take corrective actions efficiently. Given the size and time constraints of the CMS data acquisition system, efficient application monitoring is an interesting research problem. We propose an approach that uses the emerging paradigm of Web-service based eventing systems in combination with hierarchical data collection and load balancing. Scalability and efficiency are achieved by a decentralized architecture, splitting up data collections into regions of collections. An implementation following this scheme is deployed as the monitoring infrastructure of the CMS experiment at the Large Hadron Collider. All services in this distributed data acquisition system are providing standard web service interfaces via XML, SOAP and HTTP 15,22. Continuing on this path we adopted WS-* standards implementing a monitoring system layered on top of the W3C standards stack. We designed a load-balanced publisher/subscriber system with the ability to include high-speed protocols 10,12 for efficient data transmission 11,13,14 and serving data in multiple data formats.
The CMS online cluster consists of more than 2000 computers running about 10000 application instances. These applications implement the control of the experiment, the event building, the high level ...trigger, the online database and the control of the buffering and transferring of data to the Central Data Recording at CERN. In this paper the IT solutions employed to fulfil the requirements of such a large cluster are revised. Details are given on the chosen network structure, configuration management system, monitoring infrastructure and on the implementation of the high availability for the services and infrastructure.
Public procurement is an important part of the current economic reality. The economic development of Romanian companies taking part in the bidding process closely depends on the national public ...system and it cannot be achieved without an efficient and correct procurement process. This study is focused on the irregularities found as a result of a complex research regarding the public procurement system. The main objective of this research is to build a model- an applicable strategy for identifying irregularities in procurement procedures and, as such avoiding them, by taking into consideration the particularities of the bidding process, its content and methods. The number of procurement appeals gives information about participant companies’ level of dissatisfaction, while the number of the admitted appeals shows the real leaks from the system. Considering these aspects, the current paper discusses about the public procurement process and it presents the critical phases of the public procurement procedure, by emphasizing the possible weaknesses and activities that can generate irregularities in this area. Thus, by analyzing the content of many officially admitted complaints related to the public bidding process, the paper reveals the main problematic aspects of the public procurement system, contributing thus to improvement and increased satisfaction for all participants taking part in the process.
Kissiris, γ-alumina, and calcium alginate were the supports for immobilization of a cryotolerant and alcohol-resistant strain of Saccharomyces cerevisiae species. Continuous wine-making with ...immobilized cells on each above support was performed at ambient and low temperatures. To evaluate the results of continuous wine-making with immobilized cells, batch fermentations were performed using immobilized and free cells separately, in the same range of temperatures. Fourfold higher ethanol productivities at room temperature and 10-fold higher productivities at low temperatures were obtained by continuous wine-making, in comparison to batch fermentations performed with free cells. Specifically, at 7 °C, ethanol productivities achieved by continuous wine making were 16.7, 13.8, and 23.2 g L-1 day-1 and by batch wine-making were 4.5, 5.1, and 5.6 g L-1 day-1, respectively, for kissiris, γ-alumina, and calcium alginate. For free cells ethanol productivity was 1.5 g L-1 day-1 at 7 °C. The three continuous systems were operated continuously for 80 days without any infection and diminution of the ethanol productivity. Also, the wines were produced with low total and volatile acidities. Keywords: Alcoholic fermentation; wine; continuous; batch; immobilized cells; Saccharomyces cerevisiae; psychrotolerant strain
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