io.opencensus.metrics.export.MetricDescriptor Maven / Gradle / Ivy
/*
* Copyright 2018, OpenCensus Authors
*
* Licensed 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 io.opencensus.metrics.export;
import com.google.auto.value.AutoValue;
import io.opencensus.common.ExperimentalApi;
import io.opencensus.internal.Utils;
import io.opencensus.metrics.LabelKey;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.annotation.concurrent.Immutable;
/**
* {@link MetricDescriptor} defines a {@code Metric} type and its schema.
*
* @since 0.17
*/
@ExperimentalApi
@Immutable
@AutoValue
public abstract class MetricDescriptor {
MetricDescriptor() {}
/**
* Creates a {@link MetricDescriptor}.
*
* @param name name of {@code MetricDescriptor}.
* @param description description of {@code MetricDescriptor}.
* @param unit the metric unit.
* @param type type of {@code MetricDescriptor}.
* @param labelKeys the label keys associated with the {@code MetricDescriptor}.
* @return a {@code MetricDescriptor}.
* @since 0.17
*/
public static MetricDescriptor create(
String name, String description, String unit, Type type, List labelKeys) {
Utils.checkListElementNotNull(Utils.checkNotNull(labelKeys, "labelKeys"), "labelKey");
return new AutoValue_MetricDescriptor(
name,
description,
unit,
type,
Collections.unmodifiableList(new ArrayList(labelKeys)));
}
/**
* Returns the metric descriptor name.
*
* @return the metric descriptor name.
* @since 0.17
*/
public abstract String getName();
/**
* Returns the description of this metric descriptor.
*
* @return the description of this metric descriptor.
* @since 0.17
*/
public abstract String getDescription();
/**
* Returns the unit of this metric descriptor.
*
* @return the unit of this metric descriptor.
* @since 0.17
*/
public abstract String getUnit();
/**
* Returns the type of this metric descriptor.
*
* @return the type of this metric descriptor.
* @since 0.17
*/
public abstract Type getType();
/**
* Returns the label keys associated with this metric descriptor.
*
* @return the label keys associated with this metric descriptor.
* @since 0.17
*/
public abstract List getLabelKeys();
/**
* The kind of metric. It describes how the data is reported.
*
* A gauge is an instantaneous measurement of a value.
*
*
A cumulative measurement is a value accumulated over a time interval. In a time series,
* cumulative measurements should have the same start time and increasing end times, until an
* event resets the cumulative value to zero and sets a new start time for the following points.
*
* @since 0.17
*/
public enum Type {
/**
* An instantaneous measurement of an int64 value.
*
* @since 0.17
*/
GAUGE_INT64,
/**
* An instantaneous measurement of a double value.
*
* @since 0.17
*/
GAUGE_DOUBLE,
/**
* An instantaneous measurement of a distribution value. The count and sum can go both up and
* down. Used in scenarios like a snapshot of time the current items in a queue have spent
* there.
*
* @since 0.17
*/
GAUGE_DISTRIBUTION,
/**
* An cumulative measurement of an int64 value.
*
* @since 0.17
*/
CUMULATIVE_INT64,
/**
* An cumulative measurement of a double value.
*
* @since 0.17
*/
CUMULATIVE_DOUBLE,
/**
* An cumulative measurement of a distribution value. The count and sum can only go up, if
* resets then the start_time should also be reset.
*
* @since 0.17
*/
CUMULATIVE_DISTRIBUTION,
/**
* Some frameworks implemented DISTRIBUTION as a summary of observations (usually things like
* request durations and response sizes). While it also provides a total count of observations
* and a sum of all observed values, it calculates configurable quantiles over a sliding time
* window.
*
*
This is not recommended, since it cannot be aggregated.
*
* @since 0.17
*/
SUMMARY,
}
}