more refinement

Author: jack-berg

doc-snippets/prometheus-migration/src/main/java/otel/OtelHistogramAsSummary.java

@@ -0,0 +1,30 @@
+package otel;
+
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.api.metrics.Meter;
+import java.util.List;
+
+public class OtelHistogramAsSummary {
+  private static final AttributeKey<String> DEVICE_TYPE = AttributeKey.stringKey("device_type");
+  private static final Attributes THERMOSTAT = Attributes.of(DEVICE_TYPE, "thermostat");
+  private static final Attributes LOCK = Attributes.of(DEVICE_TYPE, "lock");
+
+  public static void summaryReplacement(OpenTelemetry openTelemetry) {
+    Meter meter = openTelemetry.getMeter("smart.home");
+    // No explicit bucket boundaries: captures count and sum, a good stand-in for most
+    // Summary use cases. For quantile estimation, add boundaries that bracket your thresholds.
+    DoubleHistogram deviceCommandDuration =
+        meter
+            .histogramBuilder("device.command.duration")
+            .setDescription("Time to receive acknowledgment from a smart home device")
+            .setUnit("s")
+            .setExplicitBucketBoundariesAdvice(List.of())
+            .build();
+
+    deviceCommandDuration.record(0.35, THERMOSTAT);
+    deviceCommandDuration.record(0.85, LOCK);
+  }
+}

doc-snippets/prometheus-migration/src/main/java/otel/OtelHistogramExponentialExporter.java

@@ -3,6 +3,7 @@
 import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter;
 import io.opentelemetry.sdk.metrics.Aggregation;
 import io.opentelemetry.sdk.metrics.InstrumentType;
+import io.opentelemetry.sdk.metrics.export.DefaultAggregationSelector;
 
 public class OtelHistogramExponentialExporter {
   static OtlpHttpMetricExporter createExporter() {
@@ -11,10 +12,8 @@ static OtlpHttpMetricExporter createExporter() {
     return OtlpHttpMetricExporter.builder()
         .setEndpoint("http://localhost:4318")
         .setDefaultAggregationSelector(
-            type ->
-                type == InstrumentType.HISTOGRAM
-                    ? Aggregation.base2ExponentialBucketHistogram()
-                    : Aggregation.defaultAggregation())
+            DefaultAggregationSelector.getDefault()
+                .with(InstrumentType.HISTOGRAM, Aggregation.base2ExponentialBucketHistogram()))
         .build();
   }
 }