| CMS Note | |
| Report number | CMS-CR-2009-094 |
| Title | Operational Experience with CMS Tier-2 Sites |
| Author(s) | González Caballero, Isidro (Oviedo U.) |
| Collaboration | for the CMS Collaboration |
| Submitted to | 17th International Conference on Computing in High Energy and Nuclear Physics, Prague, Czech Republic, 21 - 27 Mar 2009 |
| Submitted by | 14 May 2009 |
| Subject category | Detectors and Experimental Techniques |
| Accelerator/Facility, Experiment | CERN LHC ; CMS |
| Free keywords | COMPUTING |
| Abstract | In the CMS computing model, more than one third of the computing resources are located at \mbox{Tier-2} sites, which are distributed across the countries in the collaboration. These sites are the primary platform for user analyses; they host datasets that are created at Tier-1 sites, and users from all CMS institutes submit analysis jobs that run on those data through grid interfaces. They are also the primary resource for the production of large simulation samples for general use in the experiment. As a result, Tier-2 sites have an interesting mix of organized experiment-controlled activities and chaotic user-controlled activities. CMS currently operates about 40 Tier-2 sites in 22 countries, making the sites a far-flung computational and social network. We describe our operational experience with the sites, touching on our achievements, the lessons learned, and the challenges for the future. |
| Copyright/License | Preprint: (License: CC-BY-4.0) |
Record created 2009-08-04, last modified 2018-06-07
