org.apache.kafka.common.telemetry.internals.MetricNamingStrategy Maven / Gradle / Ivy
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* (the "License"); you may not use this file except in compliance with
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package org.apache.kafka.common.telemetry.internals;
import org.apache.kafka.common.MetricName;
/**
* {@code MetricNamingStrategy} provides a strategy pattern-based means of converting from an
* implementation-specific metric name (e.g. Kafka {@link MetricName}) representing a
* particular metric name and associated tags into a canonical {@link MetricKey}
* (name and tags) representation.
*
*
*
* Each strategy may define its own conventions for how the resulting metric should be named,
* including things such conforming name and tags to use specific casing and separators for
* different parts of the metric name.
*
*
*
* In general, a {@code MetricNamingStrategy} implementation is closely managed by another entity,
* referred to as the "telemetry reporter", as that reporter handles the conversion between different
* representations of metric names and keys.
*
*
*
* This class is primarily used by the telemetry reporter, {@link MetricsCollector}, and
* {@link MetricsEmitter} layers.
*/
public interface MetricNamingStrategy {
/**
* Converts the given metric name into a {@link MetricKey} representation.
*
* @param metricName Implementation-specific metric
* @return {@link MetricKey}
*/
MetricKey metricKey(T metricName);
/**
* Creates a derived {@link MetricKey} from an existing {@link MetricKey}.
*
*
*
* Some metrics may include multiple components derived from the same underlying source
* of data (e.g. a Meter that exposes multiple rates and a counter) in which case it may
* be desirable to create a new metric key derived from the primary one, with a different
* name for each component of the metric.
*
*
*
* Some metrics may be derived from others by the collector itself. For example, a delta
* metric might be created from a cumulative counter.
*
*
*
* This method exists so each strategy can define its own convention for how to name
* derived metrics keys.
*
*
*
* The derived key should have the same tags as the input key, and its name new name
* will typically be composed of the input key name and the component name.
*
* @param key Input {@link MetricKey} used to construct the derived key
* @param derivedComponent Name to use for the derived component of the input metric
* @return Derived {@link MetricKey} with a new metric name composed of the input key
* name and the additional name
*/
MetricKey derivedMetricKey(MetricKey key, String derivedComponent);
}