Package org.apache.bookkeeper.stats.codahale

Class FastTimer

java.lang.Object
com.codahale.metrics.Timer
org.apache.bookkeeper.stats.codahale.FastTimer
All Implemented Interfaces:
com.codahale.metrics.Counting, com.codahale.metrics.Metered, com.codahale.metrics.Metric, com.codahale.metrics.Sampling
public class FastTimer extends com.codahale.metrics.Timer
A fast and (nearly) garbage-free Rate and Response Times Timer. FastTimer uses circular arrays which are allocated upfront. Timer updates or queries never allocate new objects and thus never create garbage. A small number of new objects are allocated for snapshots when calling getSnapshot().

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static enum 
    FastTimer.Buckets
    Defines the response time buckets to use.

    Nested classes/interfaces inherited from class com.codahale.metrics.Timer

    com.codahale.metrics.Timer.Context

  • Constructor Summary

    Constructors
    Constructor
    Description
    FastTimer()
    Constructs a new timer with default time window (60 seconds) and default time buckets (fine).
    FastTimer(int timeWindowSeconds, FastTimer.Buckets buckets)
    Constructs a new timer.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    getBucket(long duration)
    Figure out which percentile bucket an event of a given duration belongs into.
    long
    getBucketBound(int b)
    Returns the upper bucket bound (inclusive) of a given bucket.
    long
    getBucketValue(int b)
    Returns the average value of a given bucket (the mean between its lower and upper bound).
    long
    getCount()
    Returns the all-time count of events this timer has seen.
    double
    getFifteenMinuteRate()
     
    double
    getFiveMinuteRate()
     
    double
    getMeanRate()
     
    int
    getNumberOfBuckets()
    Returns the number of response time buckets used by this timer.
    double
    getOneMinuteRate()
     
    double
    getRate(int seconds)
    Returns the average per-second rate of events this timer has seen.
    com.codahale.metrics.Snapshot
    getSnapshot()
    Returns a snapshot of this timer.
    protected int
    getTime()
    Returns the current absolute time (in seconds).
    void
    update(long duration, TimeUnit unit)
    Add an event to this timer.

    Methods inherited from class com.codahale.metrics.Timer

    time, time, time, timeSupplier, update

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • FastTimer

      public FastTimer()
      Constructs a new timer with default time window (60 seconds) and default time buckets (fine).

    • FastTimer

      public FastTimer(int timeWindowSeconds, FastTimer.Buckets buckets)
      Constructs a new timer.
      Parameters:
      timeWindowSeconds - the time window (in seconds) for this timer
      buckets - the type of buckets to use for response times

  • Method Details

    • getNumberOfBuckets

      public int getNumberOfBuckets()
      Returns the number of response time buckets used by this timer.
      Returns:
      the number of response time buckets

    • getBucket

      public int getBucket(long duration)
      Figure out which percentile bucket an event of a given duration belongs into.
      Parameters:
      duration - the duration (in nanoseconds)
      Returns:
      the bucket

    • getBucketBound

      public long getBucketBound(int b)
      Returns the upper bucket bound (inclusive) of a given bucket.
      Parameters:
      b - the bucket
      Returns:
      the bound (in nanoseconds)

    • getBucketValue

      public long getBucketValue(int b)
      Returns the average value of a given bucket (the mean between its lower and upper bound).
      Parameters:
      b - the bucket
      Returns:
      the average value (in nanoseconds)

    • getTime

      protected int getTime()
      Returns the current absolute time (in seconds).
      Returns:
      the current absolute time (in seconds)

    • getRate

      public double getRate(int seconds)
      Returns the average per-second rate of events this timer has seen. The computed rate is calculated for past seconds (not including the current second, which is still being updated). If the specified time exceeds the time window of this timer, the only rate of the configured time window is reported.
      Parameters:
      seconds - the number of seconds over which to calculate the average rate
      Returns:
      the average rate (per second).

    • getCount

      public long getCount()
      Returns the all-time count of events this timer has seen.
      Specified by:
      getCount in interface com.codahale.metrics.Counting
      Specified by:
      getCount in interface com.codahale.metrics.Metered
      Overrides:
      getCount in class com.codahale.metrics.Timer
      Returns:
      the all-time count of events

    • getFifteenMinuteRate

      public double getFifteenMinuteRate()
      Specified by:
      getFifteenMinuteRate in interface com.codahale.metrics.Metered
      Overrides:
      getFifteenMinuteRate in class com.codahale.metrics.Timer

    • getFiveMinuteRate

      public double getFiveMinuteRate()
      Specified by:
      getFiveMinuteRate in interface com.codahale.metrics.Metered
      Overrides:
      getFiveMinuteRate in class com.codahale.metrics.Timer

    • getMeanRate

      public double getMeanRate()
      Specified by:
      getMeanRate in interface com.codahale.metrics.Metered
      Overrides:
      getMeanRate in class com.codahale.metrics.Timer

    • getOneMinuteRate

      public double getOneMinuteRate()
      Specified by:
      getOneMinuteRate in interface com.codahale.metrics.Metered
      Overrides:
      getOneMinuteRate in class com.codahale.metrics.Timer

    • getSnapshot

      public com.codahale.metrics.Snapshot getSnapshot()
      Returns a snapshot of this timer. The computed snapshot is calculated over the complete time interval supported by this timer.
      Specified by:
      getSnapshot in interface com.codahale.metrics.Sampling
      Overrides:
      getSnapshot in class com.codahale.metrics.Timer
      Returns:
      a snapshot of this timer

    • update

      public void update(long duration, TimeUnit unit)
      Add an event to this timer.
      Overrides:
      update in class com.codahale.metrics.Timer
      Parameters:
      duration - the time duration of the event
      unit - the unit of time duration