Hey LiuLei, Gauges can go up and down, counters only go up. Snapshot doesn't actually reset anything, it's just a way for the metrics system to get an updated value. There aren't any time-based rolling metrics to my knowledge besides MutableQuantiles.
Best, Andrew On Wed, Nov 20, 2013 at 7:34 PM, lei liu <liulei...@gmail.com> wrote: > I use cdh-4.3.1 version. I am reading the code about metrics2. > > There are COUNTER and GAUGE metric type in metrics v2. What is the > difference > between the two? > > > There is @Metric MutableCounterLong bytesWritten attribute in > DataNodeMetrics, which is used to statistics written bytes per second on > DataNode.So I think the value of MutableCounterLong should be divided > by 10and be reseted to zero per ten seconds in > MutableCounterLong.snapshot > method, is that right? But MutableCounterLong.snapshot method don't do > that. I miss anything please tell me. > > Thanks, > > LiuLei >
