At one institution, the map status calculation backend job experienced an OutOfMemory error. The error in the job occurred between these two log messages in MapStatusReportCalcTaskImpl.exec().
We found that the institution has 1.1 million substitutable courses in their external data table. Since the institution was not using subsitutable courses, we turned off the switch to cause the data to not be read into memory. Do this resolved the problem at this institution; however, we need to investigate a proper solution so that this does not become a problem elsewhere.