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Printable Summary
VO auger uses LCG File Catalogue (LFC) as a central catalogue for files stored in Grid Storage Elements. The catalogue contains more than 30 million replicas and is under constant load from production jobs. Each job checks at the beginning for entries in a given directory to verify if the required file was not already produced (for example by a job that failed after having successfully uploaded the output file) and at the end of each processing step registers new files. The performance problems of the LFC in 2012 were solved by hardware upgrade. The results of comparison can be used to judge on usability of DFC if the LFC support is discontinued or if the DIRAC system is used by the VO auger.
Description of Work
We compare the performance of Dirac File Catalogue (DFC) with the LFC using the same hardware and typical VO auger access patterns. Test queries are executed in parallel from many clients on one server and also from many clients on different worker nodes on different sites. Both catalogues use the same MySQL server. Tests are run for both catalogues one by one in the same conditions. We also report on results of scalability tests on the given hardware.