CMS Data Transfer Tests Towards LHC Data taking
The CMS experiment has developed a Computing Model designed as a distributed system of computing resources and services relying on Grid technologies. The Data Management part of this model has been established, and it is being constantly exercised and improved through several kind of computing challenged, among which CMS-specific exercises. As LHC starts, CMS will need to manage tens of petabytes of data, thousands of datasets and continuous transfers among 170 CMS Institutions. To get there prepared, in early in 2007 the CMS experiment deployed a traffic load generator infrastructure, aimed at providing CMS Computing Centres (Tiers in the World-wide LHC Computing Grid) with a means for de- bugging, loadtesting and commissioning data transfer routes among them: the LoadTest infrastructure. In addition, a Debugging Data Transfers (DDT) Task Force is being created to coordinate the debugging of data transfer links in the preparation period and during the Computing Software and Analysis challenge in 2007 (CSA07). The task force aims to commission most crucial transfer routes among CMS tiers by designing and enforcing a clear procedure to debug problematic links. Experiences within the CMS LoadTest, standalone and in the context of the first outcomes of the DDT program, are reviewed and discussed.
KeywordsData Transfer Grid Technology Continuous Transfer Transfer Route Monte Carlo Simulated Data
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