StatisticsFactory (Apache Geode 1.12.4)
Date: 2021-07-21

org.apache.geode

## Interface StatisticsFactory

- All Superinterfaces:
    StatisticsTypeFactory
  All Known Implementing Classes:
    DistributedSystem

      public interface StatisticsFactory
      extends StatisticsTypeFactory

  Instances of this interface provide methods that create instances of `Statistics`. It can also be used to create instances of `StatisticDescriptor` and `StatisticsType` because it implements `StatisticsTypeFactory`. `DistributedSystem` is the only instance of this interface.

  A `StatisticsFactory` can create a `statistic` of two numeric types: `long`, and `double`. A statistic (`StatisticDescriptor`) can either be a gauge meaning that its value can increase and decrease or a counter meaning that its value is strictly increasing.

  The following code is an example of how to create a type using the api. In this example the type has two stats whose values always increase:

          StatisticsFactory f = ...;
          StatisticsType t = f.createType(
              "StatSampler",
              "Stats on the statistic sampler.",
              new StatisticDescriptor[] {
                  f.createLongCounter("sampleCount",
                                     "Total number of samples taken by this sampler.",
                                     "samples"),
                  f.createLongCounter("sampleTime",
                                      "Total amount of time spent taking samples.",
                                      "milliseconds"),
              }
          );
          this.samplerStats = f.createStatistics(t, "statSampler");
          this.sampleCountId = this.samplerStats.nameToId("sampleCount");
          this.sampleTimeId = this.samplerStats.nameToId("sampleTime");

  Later on the stat ids can be used to increment the stats:

       this.samplerStats.incLong(this.sampleCountId, 1);
       this.samplerStats.incLong(this.sampleTimeId, nanosSpentWorking / 1000000);

  The following is an example of how to create the same type using XML. The XML data:

          <?xml version="1.0" encoding="UTF-8"?>
          <!DOCTYPE statistics PUBLIC
            "-//GemStone Systems, Inc.//GemFire Statistics Type//EN"
            "http://www.gemstone.com/dtd/statisticsType.dtd">
          <statistics>
            <type name="StatSampler">
              <description>Stats on the statistic sampler.</description>
              <stat name="sampleCount" storage="long" counter="true">
                <description>Total number of samples taken by this sampler.</description>
                <unit>samples</unit>
              </stat>
              <stat name="sampleTime" storage="long" counter="true">
                <description>Total amount of time spent taking samples.</description>
                <unit>milliseconds</unit>
              </stat>
            </type>
          </statistics>

  The code to create the type:

            StatisticsFactory f = ...;
            Reader r = new InputStreamReader("fileContainingXmlData"));
            StatisticsType type = f.createTypesFromXml(r)[0];

  Since:
    GemFire 3.0
  See Also:
    Package introduction

- - ### Field Summary

    - ### Fields inherited from interface org.apache.geode.StatisticsTypeFactory

      `MAX_DESCRIPTORS_PER_TYPE`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `Statistics` | `createAtomicStatistics(StatisticsType type)` Creates and returns a `Statistics` instance of the given `type` with default ids.
    `Statistics` | `createAtomicStatistics(StatisticsType type, String textId)` Creates and returns a `Statistics` instance of the given `type`, `textId`, and with a default numeric id.
    `Statistics` | `createAtomicStatistics(StatisticsType type, String textId, long numericId)` Creates and returns a `Statistics` instance of the given `type`, `textId`, and `numericId`.
    `Statistics` | `createStatistics(StatisticsType type)` Creates and returns a `Statistics` instance of the given `type` with default ids.
    `Statistics` | `createStatistics(StatisticsType type, String textId)` Creates and returns a `Statistics` instance of the given `type`, `textId`, and with a default numeric id.
    `Statistics` | `createStatistics(StatisticsType type, String textId, long numericId)` Creates and returns a `Statistics` instance of the given `type`, `textId`, and `numericId`.
    `Statistics[]` | `findStatisticsByNumericId(long numericId)` Returns an array of all the existing statistics with the given numericId.
    `Statistics[]` | `findStatisticsByTextId(String textId)` Returns an array of all the existing statistics with the given textId.
    `Statistics[]` | `findStatisticsByType(StatisticsType type)` Returns an array of all the existing statistics of the given type.

    - ### Methods inherited from interface org.apache.geode.StatisticsTypeFactory

      `createDoubleCounter, createDoubleCounter, createDoubleGauge, createDoubleGauge, createIntCounter, createIntCounter, createIntGauge, createIntGauge, createLongCounter, createLongCounter, createLongGauge, createLongGauge, createType, createTypesFromXml, findType`

- - ### Method Detail

    - #### createStatistics

          Statistics createStatistics(StatisticsType type)

      Creates and returns a `Statistics` instance of the given `type` with default ids.

      The created instance may not be `atomic`.

    - #### createStatistics

          Statistics createStatistics(StatisticsType type,
                                      String textId)

      Creates and returns a `Statistics` instance of the given `type`, `textId`, and with a default numeric id.

      The created instance may not be `atomic`.

    - #### createStatistics

          Statistics createStatistics(StatisticsType type,
                                      String textId,
                                      long numericId)

      Creates and returns a `Statistics` instance of the given `type`, `textId`, and `numericId`.

      The created instance may not be `atomic`.

    - #### createAtomicStatistics

          Statistics createAtomicStatistics(StatisticsType type)

      Creates and returns a `Statistics` instance of the given `type` with default ids.

      The created instance will be `atomic`.

    - #### createAtomicStatistics

          Statistics createAtomicStatistics(StatisticsType type,
                                            String textId)

      Creates and returns a `Statistics` instance of the given `type`, `textId`, and with a default numeric id.

      The created instance will be `atomic`.

    - #### createAtomicStatistics

          Statistics createAtomicStatistics(StatisticsType type,
                                            String textId,
                                            long numericId)

      Creates and returns a `Statistics` instance of the given `type`, `textId`, and `numericId`.

      The created instance will be `atomic`.

    - #### findStatisticsByType

          Statistics[] findStatisticsByType(StatisticsType type)

      Returns an array of all the existing statistics of the given type.

    - #### findStatisticsByTextId

          Statistics[] findStatisticsByTextId(String textId)

      Returns an array of all the existing statistics with the given textId.

    - #### findStatisticsByNumericId

          Statistics[] findStatisticsByNumericId(long numericId)

      Returns an array of all the existing statistics with the given numericId.