Class Summary 
ApproximateHistogram 
Implements Histogram structure for computing approximate quantiles. 
CounterMap<K> 
A map from a key type to integers. 
CounterMapWithTopKey<K> 
Same as CounterMap, but also keeps track of the item with the highest count. 
Elapsed 
A stat that exports the amount of time since it was last reset. 
Entropy<T> 
Calculate the entropy of a discrete distribution of . 
JvmStats 
Convenience class to export statistics about the JVM. 
MovingAverage<T extends Number> 
Function to compute the moving average of a time series. 
MovingWindowDelta<T extends Number> 
Delta over the most recent k sample periods. 
NumericStatExporter 
Stat exporter that extracts numeric Stat s from the Stats system, and exports them
via a callerdefined sink. 
Percentile<T extends Number & Comparable<T>> 
A stats tracker to export percentiles of inputs based on a sampling rate. 
PipelineStats 
Tracks the latency of different pipeline stages in a process. 
Precision 
Precision expresses the maximum epsilon tolerated for a typical size of input
e.g.: Precision(0.01, 1000) express that we tolerate a error of 1% for 1000 entries
it means that max difference between the real quantile and the estimate one is
error = 0.01*1000 = 10
For an entry like (1 to 1000), q(0.5) will be [490 <= x <= 510] (real q(0.5) = 500) 
PrintableHistogram 

Rate<T extends Number> 
Function to compute a windowed persecond rate of a value. 
Rate.Builder<T extends Number> 

Ratio 
Function to compute the ratio of two time series. 
RequestStats 
A class to represent the statistics associated with a client connection to an external service. 
ReservoirSampler<T> 
An in memory implementation of Reservoir Sampling for sampling from
a population. 
SampledStat<T extends Number> 
A convenience class to perform the basic tasks needed for a RecordingStat except the
actual value calculation. 
Significance 
Calculate significance scores between an observed amount and an expected amount. 
SlidingStats 
Tracks event statistics over a sliding window of time. 
StatImpl<T> 
A convenience class to not require stat implementers to implement StatImpl.getName() . 
Statistics 
A simple class to keep running statistics that require O(1) storage. 
Stats 
Manages Stat s that should be exported for monitoring. 
TimeSeriesRepositoryImpl 
A simple inmemory repository for exported variables. 