hdp hive CLI进入慢的解决方案

参考如下链接中的陈述：
Hive CLI unresponsive
One thing to check is if they are using tez. If they are, it could be possible that they do not have any capacity on their YARN cluster to launch AM. So the Hive CLI waits indefinitely to launch an AM. One thing they can do to alleviate this is to launch hive cli as "hive -hiveconf hive.execution.engine=mr".
Its not that MR gets resources, Tez just pre-allocates resources, it starts a YARN application as soon as you invoke the Hive CLI. In case of MR a YARN application is launched only when its required by the executing query. This is a performance optimization in Hive on Tez saving the user the overhead of launching a AM everytime a new query is run in the same Hive CLI session.

hdp hive 会默认采用tez引擎，tez启动之前会在yarn上预申请资源，如果yarn上没有资源，只能等待，利用命令"hive -hiveconf hive.execution.engine=mr" 切换一下计算引擎，可以快速进入hive shell，因为mr不会预先申请资源。