Package io.dropwizard.metrics5

Class EWMA

java.lang.Object
io.dropwizard.metrics5.EWMA
public class EWMA extends Object
An exponentially-weighted moving average.
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    EWMA(double alpha, long interval, TimeUnit intervalUnit)
    Create a new EWMA with a specific smoothing constant.

  • Method Summary

    Modifier and Type
    Method
    Description
    static EWMA
    fifteenMinuteEWMA()
    Creates a new EWMA which is equivalent to the UNIX fifteen minute load average and which expects to be ticked every 5 seconds.
    static EWMA
    fiveMinuteEWMA()
    Creates a new EWMA which is equivalent to the UNIX five minute load average and which expects to be ticked every 5 seconds.
    double
    getRate(TimeUnit rateUnit)
    Returns the rate in the given units of time.
    static EWMA
    oneMinuteEWMA()
    Creates a new EWMA which is equivalent to the UNIX one minute load average and which expects to be ticked every 5 seconds.
    void
    reset()
    Set the rate to the smallest possible positive value.
    void
    tick()
    Mark the passage of time and decay the current rate accordingly.
    void
    update(long n)
    Update the moving average with a new value.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • EWMA

      public EWMA(double alpha, long interval, TimeUnit intervalUnit)
      Create a new EWMA with a specific smoothing constant.
      Parameters:
      alpha - the smoothing constant
      interval - the expected tick interval
      intervalUnit - the time unit of the tick interval

  • Method Details

    • oneMinuteEWMA

      public static EWMA oneMinuteEWMA()
      Creates a new EWMA which is equivalent to the UNIX one minute load average and which expects to be ticked every 5 seconds.
      Returns:
      a one-minute EWMA

    • fiveMinuteEWMA

      public static EWMA fiveMinuteEWMA()
      Creates a new EWMA which is equivalent to the UNIX five minute load average and which expects to be ticked every 5 seconds.
      Returns:
      a five-minute EWMA

    • fifteenMinuteEWMA

      public static EWMA fifteenMinuteEWMA()
      Creates a new EWMA which is equivalent to the UNIX fifteen minute load average and which expects to be ticked every 5 seconds.
      Returns:
      a fifteen-minute EWMA

    • update

      public void update(long n)
      Update the moving average with a new value.
      Parameters:
      n - the new value

    • reset

      public void reset()
      Set the rate to the smallest possible positive value. Used to avoid calling tick a large number of times.

    • tick

      public void tick()
      Mark the passage of time and decay the current rate accordingly.

    • getRate

      public double getRate(TimeUnit rateUnit)
      Returns the rate in the given units of time.
      Parameters:
      rateUnit - the unit of time
      Returns:
      the rate