org.eclipse.microprofile.metrics.annotation

Annotation Type ConcurrentGauge

@Inherited
 @Documented
 @InterceptorBinding
 @Retention(value=RUNTIME)
 @Target(value={TYPE,CONSTRUCTOR,METHOD})
public @interface ConcurrentGauge

An annotation for marking a method, constructor, or class as concurrent gauged. The metric will be registered in the application MetricRegistry. A concurrent gauge has the following semantics:

• Upon entering the marked item, the value is increased.
• Upon exiting the marked item, the value is decreased.

Given a method annotated with @ConcurrentGauge like this:

      @ConcurrentGauge(name = "fancyName")
     public String fancyName(String name) {
         return "Sir Captain " + name;
     }
 

A concurrent gauge with the fully qualified class name + fancyName will be created and each time the #fancyName(String) method is invoked, the gauge will be updated. Similarly, the same applies for a constructor annotated with @ConcurrentGauge.

Given a class annotated with @ConcurrentGauge like this:

      @ConcurrentGauge
     public class CGaugedBean {
         public void cGaugedMethod1() {}
         public void cGaugedMethod2() {}
     }
 

A counter for the defining class will be created for each of the constructors/methods. Each time the constructor/method is invoked, the respective gauge will be updated. This annotation will throw an IllegalStateException if the constructor/method is invoked, but the metric no longer exists in the MetricRegistry.

Since:

2.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	absolute Denotes whether to use the absolute name or use the default given name relative to the annotated class.
String	description The description of the concurrent gauge.
String	displayName The display name of the concurrent gauge.
String	name The name of the concurrent gauge.
String[]	tags The tags of the concurrent gauge.
String	unit The unit of the concurrent gauge.

Element Detail

name

public abstract String name

The name of the concurrent gauge.

Returns:

The name of the concurrent gauge.

Default:

""

tags

public abstract String[] tags

The tags of the concurrent gauge.

Returns:

The tags of the concurrent gauge. Each String tag must be in the form of 'key=value'. If the input is empty or does not contain a '=' sign, the entry is ignored.

See Also:

Metadata

Default:

{}

absolute

public abstract boolean absolute

Denotes whether to use the absolute name or use the default given name relative to the annotated class.

Returns:

If true, use the given name as an absolute name. If false (default), use the given name relative to the annotated class. When annotating a class, this must be false.

Default:

false

displayName

public abstract String displayName

The display name of the concurrent gauge.

Returns:

The display name of the concurrent gauge.

See Also:

Metadata

Default:

""

description

public abstract String description

The description of the concurrent gauge.

Returns:

The description of the concurrent gauge.

See Also:

Metadata

Default:

""

unit

public abstract String unit

The unit of the concurrent gauge.

Returns:

The unit of the concurrent gauge. By default, the value is MetricUnits.NONE.

See Also:

Metadata, MetricUnits

Default:

"none"