Is preemption only for FAIR ordering policy or can be used for FIFO ordering policy ?
The reason, here why I am asking this question is that we want to use Hive LLAP in our environment. However, to use LLAP, we need to enable 'YARN preemption'. We are using FIFO ordering policies. So, enabling yarn preemption will create any impact even if we are using FIFO ordering policies.
Preemption will definitely work for FIFO ordering policy. Since its FIFO ordering policy the newer applications will preempted first if the priority is same or not set. In other words, the older applications will considered for preemption only after the newer applications are preempted.