hbase-server/src/main/java/org/apache/hadoop/hbase/util/YammerHistogramUtils.java

   1 /**
   2  *
   3  * Licensed to the Apache Software Foundation (ASF) under one
   4  * or more contributor license agreements.  See the NOTICE file
   5  * distributed with this work for additional information
   6  * regarding copyright ownership.  The ASF licenses this file
   7  * to you under the Apache License, Version 2.0 (the
   8  * "License"); you may not use this file except in compliance
   9  * with the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19 package org.apache.hadoop.hbase.util;
  20
  21 import com.codahale.metrics.Histogram;
  22 import com.codahale.metrics.Reservoir;
  23 import com.codahale.metrics.Snapshot;
  24 import java.lang.reflect.Constructor;
  25 import java.text.DecimalFormat;
  26 import org.apache.yetus.audience.InterfaceAudience;
  27
  28 /** Utility functions for working with Yammer Metrics. */
  29 @InterfaceAudience.Private
  30 public final class YammerHistogramUtils {
  31
  32   // not for public consumption
  33   private YammerHistogramUtils() {}
  34
  35   /**
  36    * Used formatting doubles so only two places after decimal point.
  37    */
  38   private static DecimalFormat DOUBLE_FORMAT = new DecimalFormat("#0.00");
  39
  40   /**
  41    * Create a new {@link com.codahale.metrics.Histogram} instance. These constructors are
  42    * not public in 2.2.0, so we use reflection to find them.
  43    */
  44   public static Histogram newHistogram(Reservoir sample) {
  45     try {
  46       Constructor<?> ctor =
  47           Histogram.class.getDeclaredConstructor(Reservoir.class);
  48       ctor.setAccessible(true);
  49       return (Histogram) ctor.newInstance(sample);
  50     } catch (Exception e) {
  51       throw new RuntimeException(e);
  52     }
  53   }
  54
  55   /** @return an abbreviated summary of {@code hist}. */
  56   public static String getShortHistogramReport(final Histogram hist) {
  57     Snapshot sn = hist.getSnapshot();
  58     return "mean=" + DOUBLE_FORMAT.format(sn.getMean()) +
  59         ", min=" + DOUBLE_FORMAT.format(sn.getMin()) +
  60         ", max=" + DOUBLE_FORMAT.format(sn.getMax()) +
  61         ", stdDev=" + DOUBLE_FORMAT.format(sn.getStdDev()) +
  62         ", 95th=" + DOUBLE_FORMAT.format(sn.get95thPercentile()) +
  63         ", 99th=" + DOUBLE_FORMAT.format(sn.get99thPercentile());
  64   }
  65
  66   /** @return a summary of {@code hist}. */
  67   public static String getHistogramReport(final Histogram hist) {
  68     Snapshot sn = hist.getSnapshot();
  69     return "mean=" + DOUBLE_FORMAT.format(sn.getMean()) +
  70         ", min=" + DOUBLE_FORMAT.format(sn.getMin()) +
  71         ", max=" + DOUBLE_FORMAT.format(sn.getMax()) +
  72         ", stdDev=" + DOUBLE_FORMAT.format(sn.getStdDev()) +
  73         ", 50th=" + DOUBLE_FORMAT.format(sn.getMedian()) +
  74         ", 75th=" + DOUBLE_FORMAT.format(sn.get75thPercentile()) +
  75         ", 95th=" + DOUBLE_FORMAT.format(sn.get95thPercentile()) +
  76         ", 99th=" + DOUBLE_FORMAT.format(sn.get99thPercentile()) +
  77         ", 99.9th=" + DOUBLE_FORMAT.format(sn.get999thPercentile()) +
  78         ", 99.99th=" + DOUBLE_FORMAT.format(sn.getValue(0.9999)) +
  79         ", 99.999th=" + DOUBLE_FORMAT.format(sn.getValue(0.99999));
  80   }
  81
  82   /** @return pretty summary of {@code hist}. */
  83   public static String getPrettyHistogramReport(final Histogram h) {
  84     Snapshot sn = h.getSnapshot();
  85     return
  86         "Mean      = " + DOUBLE_FORMAT.format(sn.getMean()) + "\n" +
  87         "Min       = " + DOUBLE_FORMAT.format(sn.getMin()) + "\n" +
  88         "Max       = " + DOUBLE_FORMAT.format(sn.getMax()) + "\n" +
  89         "StdDev    = " + DOUBLE_FORMAT.format(sn.getStdDev()) + "\n" +
  90         "50th      = " + DOUBLE_FORMAT.format(sn.getMedian()) + "\n" +
  91         "75th      = " + DOUBLE_FORMAT.format(sn.get75thPercentile()) + "\n" +
  92         "95th      = " + DOUBLE_FORMAT.format(sn.get95thPercentile()) + "\n" +
  93         "99th      = " + DOUBLE_FORMAT.format(sn.get99thPercentile()) + "\n" +
  94         "99.9th    = " + DOUBLE_FORMAT.format(sn.get999thPercentile()) + "\n" +
  95         "99.99th   = " + DOUBLE_FORMAT.format(sn.getValue(0.9999)) + "\n" +
  96         "99.999th  = " + DOUBLE_FORMAT.format(sn.getValue(0.99999));
  97   }
  98 }