You are right, the Matrix Projects configuration does the trick. Tx for the hint! :-)
The only drawback with that approach is that I cannot just specify the slave label that needs to be traversed. Instead I have to explicitly list all the slaves that need to be visited by the admin task. This should be fine for most occasions but in the event that a slave went down then the top job will never complete as it cannot reach the specified slave. Also, if a new slave is added in that category then I must remember to add it to this admin job.... Not perfect but it will do for now. Again, tx for the hint. If you happen to have a better idea then please drop it by! ;-)
