부산대학교 도서관

The Consumer-Server/Logger (CSL) is the final component in the CDF Data Acquisition chain before data is archived to tape. The CSL buffers data in separate data streams, records file meta information into a database and sends a fraction of events to online processors for real time monitoring of data quality. Recently, the CSL was upgraded in order to increase the logging capacity to 80 MB/s. The upgrade consists of commodity servers running Linux. A "Receiver node" distributes data via Gigabit Ethernet to eight parallel "Logger nodes" connected to external disk arrays via a Fibre Channel network. A redundant design and the availability of inexpensive large capacity disk arrays provides a highly available system that is scalable and easy to maintain. We present a description of the CSL upgrade and discuss the experience gained through commissioning to operations.