org.apache.nifi.controller.status.history

Interface MetricDescriptor<T>

Type Parameters:

T - type of metric

public interface MetricDescriptor<T>

Describes a particular metric that is derived from a Status History

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	MetricDescriptor.Formatter

Field Summary

Fields

Modifier and Type	Field and Description
static int	FRACTION_MULTIPLIER Used during creation of metric instance with MetricDescriptor.Formatter.FRACTION formatting.

Method Summary

Modifier and Type	Method and Description
String	getDescription()
String	getField()
MetricDescriptor.Formatter	getFormatter() Specifies how the values should be formatted
String	getLabel()
int	getMetricIdentifier()
ValueMapper<T>	getValueFunction()
ValueReducer<StatusSnapshot,Long>	getValueReducer()
boolean	isCounter()

Field Detail

FRACTION_MULTIPLIER

static final int FRACTION_MULTIPLIER

Used during creation of metric instance with MetricDescriptor.Formatter.FRACTION formatting. The expected way is to multiply the floating point metric value with it before converting into long. By this, enough of the fractional part might be kept for visualisation. In order to show the correct number the result must be divided with the same number before presenting.

See Also:

Constant Field Values

Method Detail

getMetricIdentifier

int getMetricIdentifier()

getFormatter

MetricDescriptor.Formatter getFormatter()

Specifies how the values should be formatted

Returns:

formatter for values

getDescription

String getDescription()

Returns:

a human-readable description of the field

getLabel

String getLabel()

Returns:

a human-readable label for the field

getField

String getField()

Returns:

the name of a field

getValueFunction

ValueMapper<T> getValueFunction()

Returns:

a ValueMapper that can be used to extract a value for the status history

getValueReducer

ValueReducer<StatusSnapshot,Long> getValueReducer()

Returns:

a ValueReducer that can reduce multiple StatusSnapshots into a single Long value

isCounter

boolean isCounter()

Returns:

true if the metric is for a component Counter, false otherwise