I think this has gone stale. Lets move forward.
YARN-4304, one of the small improvement was to hide maxAMPercentageLimit for parent queue. We achieved this by declaring this variable as Float and was setting to null if queue is ParentQueue.
Now we have got this corner scenario when labels are available in cluster, and no label-mappings are defined in CS. We have fixed partially in
YARN-4634, however we can still have some more cases like here. So ideally its better to handle null check for getMaxAMPercentageLimit from UI to keep the improvement what we have done as part of YARN-4304.
But after seeing the findbug warning, essentially we are boxing and unboxing this float variable. And I could see that there are some other parrellel effort going on in other tickets to avoid such cases.
So I think we can still keep float and avoid this problem. But we will loose small part of improvement there. So I think may be we can group this new metrics (maxAMPercentageLimit etc) in other DAO object and can use it. If its fine we can go with v1 patch here and unblock the scheduler issue. And other improvement can be tracked separately. Wangda Tan, Could you pls share your thoughts here.