io.opentelemetry.metrics

Interface DoubleObserver

All Superinterfaces:

Instrument, Observer<DoubleObserver.ResultDoubleObserver>

@ThreadSafe
public interface DoubleObserver
extends Observer<DoubleObserver.ResultDoubleObserver>

Observer to report pre-aggregated metrics with double value.

Example:

 class YourClass {

   private static final Meter meter = OpenTelemetry.getMeterRegistry().get("my_library_name");
   private static final DoubleObserver observer =
       meter.
           .observerDoubleBuilder("doWork_latency")
           .setDescription("gRPC Latency")
           .setUnit("ms")
           .build();
   private static final LabelSet labelSet = meter.createLabelSet("my_label");

   void init() {
     observer.setCallback(
         new DoubleObserver.Callback<DoubleObserver.ResultDoubleObserver>() {
           final AtomicInteger count = new AtomicInteger(0);
          {@literal @}Override
           public void update(Result result) {
             result.observe(0.8 * count.addAndGet(1), labelSet);
           }
         });
   }
 }
 

Since:

0.1.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	DoubleObserver.Builder Builder class for DoubleObserver.
static interface	DoubleObserver.ResultDoubleObserver The result for the Observer.Callback.

Nested classes/interfaces inherited from interface io.opentelemetry.metrics.Observer

Observer.Callback<R>

Method Summary

Modifier and Type	Method and Description
void	setCallback(Observer.Callback<DoubleObserver.ResultDoubleObserver> metricUpdater) Sets a callback that gets executed every time before exporting this metric.

Method Detail

setCallback

void setCallback(Observer.Callback<DoubleObserver.ResultDoubleObserver> metricUpdater)

Description copied from interface: Observer

Sets a callback that gets executed every time before exporting this metric.

Evaluation is deferred until needed, if this Observer metric is not exported then it will never be called.

Specified by:

setCallback in interface Observer<DoubleObserver.ResultDoubleObserver>

Parameters:

metricUpdater - the callback to be executed before export.