We use stateless session beans. all beans are defined with transaction type 'Container'. Meaning that when one ejb calls a service of another ejb as a client and so on - all called are handled in one transaction.
we have one exceptional ejb that uses services of other ejbs as client but should not be affected by a rollback that one of them can generate. it should go on with its flow. on the other hand if the initial(calling) ejb is rolled back, i need that all the other ejbs which were already called will also be rolled back.