org.apache.hadoop.metrics2.annotation

Annotation Type Metric

@InterfaceAudience.Public
@InterfaceStability.Evolving
@Documented
@Target(value={FIELD,METHOD})
@Retention(value=RUNTIME)
public @interface Metric

Annotation interface for a single metric

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	about
boolean	always
String	sampleName
org.apache.hadoop.metrics2.annotation.Metric.Type	type
String[]	value Shorthand for optional name and description
String	valueName

Element Detail

value

public abstract String[] value

Shorthand for optional name and description

Returns:

{description} or {name, description}

Default:

{}

about

public abstract String about

Returns:

optional description of the metric

Default:

""

sampleName

public abstract String sampleName

Returns:

optional sample name for MutableStat/Rate/Rates

Default:

"Ops"

valueName

public abstract String valueName

Returns:

optional value name for MutableStat/Rate/Rates

Default:

"Time"

always

public abstract boolean always

Returns:

true to create a metric snapshot even if unchanged.

Default:

false

type

public abstract org.apache.hadoop.metrics2.annotation.Metric.Type type

Returns:

optional type (counter|gauge) of the metric

Default:

org.apache.hadoop.metrics2.annotation.Metric.Type.DEFAULT