Hi, The high-level use case is to monitor/track/update job information in its entirety by potential actors like users, high level middleware services, schedulers, etc... some general requirements for activity schema; Normally, activity document contains the job description as a JSDL instance sent by a user. In terms of UNICORE, the activity document not only contains user submitted JSDL instance but it also maintains the JSDL instance incarnated by the backend execution management system during job execution. Another UNICORE requirement is that the activity instance includes computing job attributes with associated storage information. Particularly UNICORE does this by adding a Storage Management Service (SMS) reference within activity properties document in order to enable clients to manage remote storages. Activity schema can also represent the events occurred during the lifetime of a job. In other words one may take it as job version information and each of its instance may include the job status and time stamp elements. This information should not be over loaded with bits and pieces of each job description item such as resources consumed or JSDL instance. Activity instance contains the resource allocation (consumption) information, it means what resources in real time are/or will be allocated to a job. In a multi-resource environment, this information can also capture exceptions during a job execution, such as job is interrupted due to node failures or resource starvation; or it has been transferred to another server instance. In general, this information is significant to the middleware components managing job recovery and checkpointing functions in the event of failovers. Cheers, -- ------------------ Mohammad Shahbaz Memon Distributed Systems and Grid Computing Jülich Supercomputing Center Forschungszentrum Jülich GmbH Jülich Germany Office: +49 (0)2461 61 6567 Fax: +49 (0)2461 61 6656 http://www.fz-juelich.de/jsc Sitz der Gesellschaft: Jülich Eingetragen im Handelsregister des Amtsgerichts Düren Nr. HR B 3498 Vorsitzende des Aufsichtsrats: MinDirig'in Bärbel Brumme-Bothe Vorstand: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender)