> Depends on how you configured scheduling in yarn ... ... >> you won't have this problem if you use Spark as the execution engine? >>That handles concurrency OK
If I read this right, it is unlikely to be related to YARN configs. The Hue issue is directly related to how many Tez/Spark sessions are supported per-connection-handle. hive.server2.parallel.ops.in.session I would guess that this is queuing up in the getSessionManager().submitBackgroundOperation() call talking to SparkSessionManagerImpl/TezSessionPoolManager. MR has no equivalent of a "session" in relation to the cluster, because as a non-DAG engine it has to have the "parallel job queue" built over to support parallel stages. Cheers, Gopal
