No. 121 (00257) Family name : MOSCICKI Given name : Jakub Affiliation : CERN Abbreviation : E-mail address : Jakub.Moscicki@cern.ch Title : Application Workflow Management on the GRID Authors : Jakub T.Moscicki Abstract : GRID middleware provides basic services and foundation frameworks for building global environments for scientific computing. Low level issues are addressed such as security, virtual organizations, data replication, job submission and execution. DIANE framework (http://cern.ch/diane) is a generic workflow manager for distributed master-worker applications, which builds on top of the existing GRID middleware providing high-level facilities and idioms for application development and deployment. DIANE may be easily deployed into a concrete GRID environment such as Globus Toolkit or used in standalone clusters with popular workload management systems such as LSF or PBS. DIANE is a callback framework which controls the job execution, creates tasks and workers, passes data messages between the master and the workers and finally integrates the task output. Applications do not have to open communication channels explicitly -- this setup is done automatically. Fixing master-worker parallel computation model limits the generality of the applications but enormously increases the flexibility of the framework itself in a way completely transparent to applications. Runtime flexibility allows to switch between in-process application loading based on shared libraries and IPC-based application execution based on statically-linked executables. Both setups have practical implications and DIANE offers a convenience to choose the appropriate one in an easy way. Architecture of DIANE is based on component-container object model, which allows creation of various Application Adapters to enhance the framework easily. Application Adapters provided by default support python and C++ bindings, as well as mixing the two in single job. The paper presents basic architecture and design principles of DIANE and benchmark results of distributed simulation in biomedical applications.