Dear all, I got a new use case for the Application Environment from Tibor Kalman (working on InstantGrid). He would like to be able to discover if an Application Environment depends on other Application Environments in order to be used. Let's say that in a ComputingService, you have three installed application environments (which LocalID are AE1, AE2 and AE3). It could happen that a user wants to use AE1 for its job, but this will imply that AE1 has to use AE2 and AE3. The scheduler should be able to discover this in order to correctly submit the job. The dependency can be captured by referring to the LocalID of the application on which another application depends on. The questions are: 1. is there anybody else who has this requirement? 2. how could we model this in GLUE? option a. add directed association from Application Environment to Application Environment which with label "Depends On" option b. add multi-value Dependency attribute to Application Environment class (basically an implementation of the association in option a.) option c. suggests usage of auxiliary entities Please, send your comments on this issue. Cheers, Sergio -- Sergio Andreozzi INFN-CNAF, Tel: +39 051 609 2860 Viale Berti Pichat, 6/2 Fax: +39 051 609 2746 40126 Bologna (Italy) Web: http://www.cnaf.infn.it/~andreozzi