org.apache.sling.commons.metrics

Interface Gauge<T>

Type Parameters:

T - the type of the metric's value

@ConsumerType
public interface Gauge<T>

A gauge metric is an instantaneous reading of a particular value. Since package version 1.3.0 a gauge can directly created via the MetricsService MetricsService.gauge(String,Supplier), which should be used for the majority of cases.

Nevertheless it's still possible to register a gauge instance with OSGi ServiceRegistry with Gauge#NAME set to Gauge name. Then the Gauge instance would be registered with MetricService via the whiteboard pattern. To instrument a queue's depth, for example:

 final Queue<String> queue = new ConcurrentLinkedQueue<String>();
 final Gauge<Integer> queueDepth = new Gauge<Integer>() {
     public Integer getValue() {
         return queue.size();
     }
 };
 

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	NAME Service property name which determines the name of the Gauge

Method Summary

Modifier and Type	Method and Description
T	getValue() Returns the metric's current value.

Field Detail

NAME

static final java.lang.String NAME

Service property name which determines the name of the Gauge

See Also:

Constant Field Values

Method Detail

getValue

T getValue()

Returns the metric's current value.

Returns:

the metric's current value