/**
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.util;
import com.yammer.metrics.core.Histogram;
import com.yammer.metrics.stats.Sample;
import com.yammer.metrics.stats.Snapshot;
import java.lang.reflect.Constructor;
import java.text.DecimalFormat;
/** Utility functions for working with Yammer Metrics. */
public final class YammerHistogramUtils {
// not for public consumption
private YammerHistogramUtils() {}
/**
* Used formatting doubles so only two places after decimal point.
*/
private static DecimalFormat DOUBLE_FORMAT = new DecimalFormat("#0.00");
/**
* Create a new {@link com.yammer.metrics.core.Histogram} instance. These constructors are
* not public in 2.2.0, so we use reflection to find them.
*/
public static Histogram newHistogram(Sample sample) {
try {
Constructor<?> ctor =
Histogram.class.getDeclaredConstructor(Sample.class);
ctor.setAccessible(true);
return (Histogram) ctor.newInstance(sample);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/** @return an abbreviated summary of {@code hist}. */
public static String getShortHistogramReport(final Histogram hist) {
Snapshot sn = hist.getSnapshot();
return "mean=" + DOUBLE_FORMAT.format(hist.mean()) +
", min=" + DOUBLE_FORMAT.format(hist.min()) +
", max=" + DOUBLE_FORMAT.format(hist.max()) +
", stdDev=" + DOUBLE_FORMAT.format(hist.stdDev()) +
", 95th=" + DOUBLE_FORMAT.format(sn.get95thPercentile()) +
", 99th=" + DOUBLE_FORMAT.format(sn.get99thPercentile());
}
/** @return a summary of {@code hist}. */
public static String getHistogramReport(final Histogram hist) {
Snapshot sn = hist.getSnapshot();
return ", mean=" + DOUBLE_FORMAT.format(hist.mean()) +
", min=" + DOUBLE_FORMAT.format(hist.min()) +
", max=" + DOUBLE_FORMAT.format(hist.max()) +
", stdDev=" + DOUBLE_FORMAT.format(hist.stdDev()) +
", 50th=" + DOUBLE_FORMAT.format(sn.getMedian()) +
", 75th=" + DOUBLE_FORMAT.format(sn.get75thPercentile()) +
", 95th=" + DOUBLE_FORMAT.format(sn.get95thPercentile()) +
", 99th=" + DOUBLE_FORMAT.format(sn.get99thPercentile()) +
", 99.9th=" + DOUBLE_FORMAT.format(sn.get999thPercentile()) +
", 99.99th=" + DOUBLE_FORMAT.format(sn.getValue(0.9999)) +
", 99.999th=" + DOUBLE_FORMAT.format(sn.getValue(0.99999));
}
}