Actually, scratch what I just said - that advice applies if the query is stuck in the FINISHED state. If it's stuck in the RUNNING state, it means the query is just taking a long time to produce any results. So you're probably getting a bad query plan on one cluster that is extremely slow to execute. E.g. the order of the joins chosen by the planner is inefficient. Usually computing stats on all the tables will improve the query plan. ... View more