物理分析平台建设研究2013年度报告

王萌 李卫东 何苗 齐法制 石京燕

摘要：2013年，大亚湾实验已经进入稳定取数阶段，物理分析平台的任务是针对不断增加的数据量，提高计算能力和存储能力；根据物理分析的需求，开发或改进探测器刻度算法和重建算法，进行数据和模拟的比较，并提高物理分析的效率。 在计算环境方面，我们扩大了CPU和硬盘资源，开发了计算资源监视系统，建立了计算环境监控管理系统。在数据存储方面，本年度建成了一个574TB的磁盘存储系统。系统基于在高性能计算领域广泛应用的开源Lustre分布式文件系统，完全采用商品服务器和存储设备构建。课题组针对大亚湾现场网络和计算环境设计并实现了大亞湾现场网络系统运行支撑平台。在大亚湾现场和高能所都部署了传输系统的数据缓冲模块。并添加了传输监视系统。 在软件算法方面，通过对同时穿过不同探测器、实验厅的缪子事例的触发时刻延迟分析，得到了各探测器之间的时间延迟。通过强制触发数据得到了阻性板室探测器的层噪声率和模块噪声率。开发了MC Tuning软件框来管理模拟参数，通过xml文件和txt文件对不同的参数进行分组管理。根据大亚湾物理分析的特点，设计了新的软件框架，确定了数据模型的定义，并设计、实现了满足分析需求的事例缓存机制。

关键词：大亚湾；计算；存储；网络；软件框架；刻度；模拟

2013 annual report of the physics analysis platform

Abstract：In 2013， the Daya Bay experiment is taking data stably. The physics analysis platform aims at improving the ability of computing and data storage according to accumulated data volume， detector calibration， event reconstruction， MC tuning， and analysis efficiency. The computing resources and hard disks have been increased. A computing resource monitoring system and a computing environment management system were developed. A 574TB Lustre data storage system was established. According to the Daya Bay network and computing environment， an onsite network support platform was designed and implemented. The data buffer module as well as the monitor system was deployed at both onsite and IHEP for better data transfer. For the offline software， a calibration algorithm was developed using cosmic muon events to get the time latency between different detectors. The layer noise rate and module noise rate of the resistive plate chambers were obtained with the forced trigger events. A MC Tuning software framework was developed to manage simulation parameters. A new lightweight analysis framework was proposed and the data model was defined as well as the event buffer mechanism.

Keywords：Daya Bay； computing； storage； network；software framework； calibration； simulation

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