Latency sample

micrometer-samples/src/main/java/io/micrometer/core/samples/LatencySample.java

@@ -0,0 +1,49 @@
+package io.micrometer.core.samples;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Timer;
+import io.micrometer.core.samples.utils.SampleRegistries;
+import reactor.core.publisher.Flux;
+
+import java.time.Duration;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+public class LatencySample {
+    public static void main(String[] args) {
+        new LatencySample().run();
+    }
+
+    private MeterRegistry registry = SampleRegistries.jmx();
+    private Random r = new Random();
+    private Timer timer = Timer.builder("request")
+        .publishPercentileHistogram()
+        .register(registry);
+
+    void bar() {
+        registry.timer("bar.latency")
+            .record(() -> {
+                // do something here
+            });
+    }
+
+    void run() {
+
+
+        Flux.interval(Duration.ofMillis(1))
+            .doOnEach(n -> recordGaussian(10))
+            .subscribe();
+
+        Flux.interval(Duration.ofSeconds(1))
+            .doOnEach(n -> recordGaussian(300))
+            .blockLast();
+    }
+
+    private void recordGaussian(long center) {
+        timer.record(simulatedLatency(center), TimeUnit.MILLISECONDS);
+    }
+
+    private long simulatedLatency(long center) {
+        return (long) (r.nextGaussian() * 10) + center;
+    }
+}