Package org.acemq.workloads.metrics

Class LatencySummary

java.lang.Object
org.acemq.workloads.metrics.LatencySummary
public final class LatencySummary extends Object
Latency percentiles from one run.

The percentiles are reported and the mean is available but deliberately not printed first. A mean latency is the number least likely to describe anybody's experience: it hides the tail entirely, and the tail is what users notice and what capacity planning is about.

  • Method Details

    • empty

      public static LatencySummary empty(String name)
      Returns:
      an empty summary, for a measurement that recorded nothing

    • name

      public String name()

    • count

      public long count()
      Returns:
      how many observations this is built from

    • min

      public Duration min()

    • max

      public Duration max()

    • mean

      public Duration mean()

    • p50

      public Duration p50()

    • p90

      public Duration p90()

    • p99

      public Duration p99()

    • p999

      public Duration p999()
      Returns:
      the 99.9th percentile: one request in a thousand is worse than this

    • p9999

      public Duration p9999()

    • percentile

      public Duration percentile(double percentile)
      Parameters:
      percentile - between 0 and 100
      Returns:
      the value at it

    • tailRatio

      public double tailRatio()
      Returns:
      how many times worse the 99th percentile is than the median. Above about 10 the distribution has a tail worth explaining — a mean or a median alone would not show it

    • isEmpty

      public boolean isEmpty()
      Returns:
      whether anything was recorded

    • format

      public String format()
      Returns:
      a fixed-width line for a report

    • toString

      public String toString()
      Overrides:
      toString in class Object