MutableCounterLong and MutableCounterLong class difference in metrics v2

[lei liu]

I use hadoop-2.0.5, there are MutableCounterLong and  MutableCounterLong
class in metrics v2.

I am studing metrics v2 code.

What are difference MutableCounterLong and  MutableCounterLong class ?

I find the MutableCounterLong is used to calculate throughput,  is that
right?  How does the metrics v2 to handle MutableCounterLong  class?


Thanks,

LiuLei