The (WLCG) Common Computing Readiness Challenge (CCRC'08)

Since several years the four LHC experiments have been running periodic stress tests of their planned computing operations when LHC data arrives. They have written design documents which describe their models for how they will acquire, distribute and process their data. They differ in details but have a common base in a model of levels or 'Tiers' of resources. A weakness of all the tests done is that they have never overlapped all the experiments together so never reached the full rates expected at CERN and the Tier sites and never had to cope with the lack of homogeneity of having the 4 different experiment data management and batch processing models being busy at the same time. The CCRC08 (Common Computing Readiness Challenge) tests address this by deliberately exercising all experiments computing at the target rates at the same time.