Distributed analysis functional testing using GangaRobot in the ATLAS experiment

Automated distributed analysis tests are necessary to ensure smooth operations of the ATLAS grid resources. In this work we present the recent developments of the ATLAS GangaRobot, a tool designed to perform regular tests of all grid sites by running arbitrary user applications with varied configurations at predifined time intervals. Specifically the GangaRobot creates and submits several real ATLAS user applications to the various grid sites using the distributed analysis framework GANGA, a front end for easy grid job definition and management. Success or failure rates of these test jobs are individually monitored. Test definitions and results are stored in a database and made available to users and site administrators through a web interface, the ATLAS Site Status Board (SSB) and the Service Availability Monitor (SAM). The test results provide on the one hand a fast way to to identify systematic or temporary site problems, and on the other hand allow for an effective distribution of the workload on the available resources.