To expand on what Anchal said, the Rebean service that is required by the ReportEngine is part of the Adaptive Processing Server (APS). Best practice for memory management is to split the single APS up into a set of APS' each of which contains a limited set of the server processes that run in the APS. Usually the Rebean service is part of one of the Webi APS'. So, you can go to the Web Intelligence service category under Servers in the CMC and look at any APS' that are available there to see whether the Rebean service is running.
-Dell