How to use all yarn cluster resources for one tez job

[skaterQiang]

Hello guys:
         I have a hive full scan job , with hive on mr I can fully use the 
whole cluster's 1000 cpu vcores(I use the split size to make mapper tasks to be 
1200),
But in tez, tez only use around 700 vcores, I have also set the same hive split 
size. So how do I configure tez? to make tez fully use all the cluster 
resources?




Thanks in advance,