Package org.eclipse.microprofile.metrics

@Version("2.0") package org.eclipse.microprofile.metrics

MicroProfile Metrics

Rational

To ensure reliable operation of software it is necessary to monitor essential system parameters. There is already JMX as standard to expose metrics, but remote-JMX is not easy to deal with and especially does not fit well in a polyglot environment where other services are not running on the JVM. To enable monitoring in an easy fashion, the MicroProfile Metrics specification provides a standard to instrument an application with metrics and provides a simple REST endpoint for integration with monitoring services.

Adding Metrics

MicroProfile Metrics provides 5 different metric types that can be used to instrument an application. Developers can create an accompanying Metadata object to supply the metric's name, description, display name, tags, and units. Once the metric and the metadata are registered against the application MetricRegistry, the metrics will be available in the REST endpoints.

Metric Types

Counter is used to measure an increasing value.

Example usage:

 
     Counter count = metricRegistry.counter(metadata);
     count.inc();
 
 

Gauge is used to provide the immediate measurement of a value.

Example usage:

 
     Gauge<Double> temperature = new Gauge<Double>() {
         public Double getValue() {
             return getTemperature();
         }
     };
     metricRegistry.register(metadata, temperature);
 
 

Meter is used to measure the frequency of an event.

Example usage:

 
     Meter meter = metricRegistry.meter(metadata);
     meter.mark();
 
 

Histogram is used to sample and compute the distribution of values

Example usage:

 
     Histogram histogram = metricRegistry.histogram(metadata);
     histogram.update(score);
 
 

Timer is used to measure the duration of an event as well as the frequency of occurrence.

Example usage:

 
     Timer timer = metricRegistry.timer(metadata);
     Timer.Context context = timer.time();

     ... // code that will be timed

     context.close();
 
 

Related Packages

Package	Description
org.eclipse.microprofile.metrics.annotation	This package contains the annotations used for MicroProfile Metrics.

Class	Description
ConcurrentGauge	A concurrent gauge is a gauge that measures parallel invocations of a method.
Counter	An incrementing counter metric.
Counting	An interface for metric types which have counts.
DefaultMetadata	The default implementation of Metadata
Gauge<T>	A gauge metric is an instantaneous reading of a particular value.
Histogram	A metric which calculates the distribution of a value.
Metadata	Bean holding the metadata of one single metric.
MetadataBuilder	The Metadata builder.
Meter	A meter metric which measures mean throughput and one-, five-, and fifteen-minute exponentially-weighted moving average throughputs.
Metered	An object which maintains mean and exponentially-weighted rate.
Metric	A tag interface to indicate that a class is a metric.
MetricFilter	A filter used to determine whether or not a metric should be reported, among other things.
MetricID	A unique identifier for Metric and Metadata that are registered in the MetricRegistry The MetricID contains: Name: (Required) The name of the metric.
MetricRegistry	The registry that stores metrics and their metadata.
MetricRegistry.Type	An enumeration representing the scopes of the MetricRegistry
MetricType	An enumeration representing the different types of metrics.
MetricUnits	Standard units constants for metric's Metadata.
Sampling	An object which samples values.
Snapshot	A statistical snapshot of a Snapshot.
Tag	Tag represents a singular metric tag key and value pair.
Timer	A timer metric which aggregates timing durations and provides duration statistics, plus throughput statistics via Meter.
Timer.Context	A timing context.