Hi Lei, MutableCounterLong is a type of counter which can be increased only (count number is often large comparing with MutableCounterInt). It is used a lot in Hadoop metrics system, i.e. DatanodeMetrics. You can find more details on metrics v2 in Hadoop wiki link ( http://wiki.apache.org/hadoop/HADOOP-6728-MetricsV2 ) and related JIRAs (under HADOOP-6728). Hope it helps.
Thanks, Junping ----- Original Message ----- From: "lei liu" <[email protected]> To: [email protected] Sent: Friday, August 9, 2013 12:09:13 PM Subject: MutableCounterLong and MutableCounterLong class difference in metrics v2 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
