Fix declarative Jaeger sampler interval configuration

sdk-extensions/jaeger-remote-sampler/build.gradle.kts

@@ -33,6 +33,8 @@ dependencies {
 
   testImplementation(project(":sdk:testing"))
   testImplementation(project(":sdk-extensions:autoconfigure"))
+  testImplementation(project(":sdk-extensions:declarative-config"))
+  testImplementation(project(":api:incubator"))
   testImplementation("com.google.guava:guava")
   testImplementation("com.google.protobuf:protobuf-java")
   testImplementation("com.linecorp.armeria:armeria-junit5")

sdk-extensions/jaeger-remote-sampler/src/main/java/io/opentelemetry/sdk/extension/trace/jaeger/sampler/JaegerRemoteSampler.java

@@ -45,6 +45,7 @@ public final class JaegerRemoteSampler implements Sampler {
   private final AtomicBoolean isShutdown = new AtomicBoolean();
 
   private final GrpcSender grpcSender;
+  private final int pollingIntervalMs;
 
   JaegerRemoteSampler(
       GrpcSender grpcSender,
@@ -53,6 +54,7 @@ public final class JaegerRemoteSampler implements Sampler {
       Sampler initialSampler) {
     this.serviceName = serviceName != null ? serviceName : "";
     this.grpcSender = grpcSender;
+    this.pollingIntervalMs = pollingIntervalMs;
     this.sampler = initialSampler;
     pollExecutor = Executors.newScheduledThreadPool(1, new DaemonThreadFactory(WORKER_THREAD_NAME));
     pollFuture =
@@ -174,6 +176,11 @@ Sampler getSampler() {
     return this.sampler;
   }
 
+  // Visible for testing
+  int getPollingIntervalMs() {
+    return this.pollingIntervalMs;
+  }
+
   public static JaegerRemoteSamplerBuilder builder() {
     return new JaegerRemoteSamplerBuilder();
   }

sdk-extensions/jaeger-remote-sampler/src/main/java/io/opentelemetry/sdk/extension/trace/jaeger/sampler/internal/JaegerRemoteSamplerComponentProvider.java

@@ -47,7 +47,7 @@ public Sampler create(DeclarativeConfigProperties config) {
     }
     builder.setInitialSampler(DeclarativeConfiguration.createSampler(initialSamplerModel));
 
-    Long pollingIntervalMs = config.getLong("internal");
+    Long pollingIntervalMs = config.getLong("interval");
     if (pollingIntervalMs != null) {
       builder.setPollingInterval(Duration.ofMillis(pollingIntervalMs));
     }

sdk-extensions/jaeger-remote-sampler/src/test/java/io/opentelemetry/sdk/extension/trace/jaeger/sampler/JaegerRemoteSamplerComponentProviderTest.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.extension.trace.jaeger.sampler;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
+import io.opentelemetry.internal.testing.slf4j.SuppressLogger;
+import io.opentelemetry.sdk.autoconfigure.declarativeconfig.DeclarativeConfiguration;
+import io.opentelemetry.sdk.extension.trace.jaeger.sampler.internal.JaegerRemoteSamplerComponentProvider;
+import io.opentelemetry.sdk.trace.samplers.Sampler;
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+import org.junit.jupiter.api.Test;
+
+// Connecting to the (unavailable) endpoint during the initial poll logs a warning; suppress it.
+@SuppressLogger(JaegerRemoteSampler.class)
+class JaegerRemoteSamplerComponentProviderTest {
+
+  private static final int DEFAULT_POLLING_INTERVAL_MILLIS = 60000;
+
+  @Test
+  void create_appliesConfiguredInterval() {
+    // Regression test for reading the wrong declarative config key: the property is "interval", so
+    // reading "internal" silently dropped the operator's value and fell back to the default.
+    Sampler sampler =
+        create(
+            "endpoint: http://localhost:14250\n"
+                + "interval: 10000\n"
+                + "initial_sampler:\n"
+                + "  always_off: {}\n");
+    try {
+      assertThat(((JaegerRemoteSampler) sampler).getPollingIntervalMs()).isEqualTo(10000);
+    } finally {
+      ((JaegerRemoteSampler) sampler).shutdown();
+    }
+  }
+
+  @Test
+  void create_defaultsIntervalWhenOmitted() {
+    Sampler sampler =
+        create("endpoint: http://localhost:14250\n" + "initial_sampler:\n" + "  always_off: {}\n");
+    try {
+      assertThat(((JaegerRemoteSampler) sampler).getPollingIntervalMs())
+          .isEqualTo(DEFAULT_POLLING_INTERVAL_MILLIS);
+    } finally {
+      ((JaegerRemoteSampler) sampler).shutdown();
+    }
+  }
+
+  private static Sampler create(String yaml) {
+    DeclarativeConfigProperties config =
+        DeclarativeConfiguration.toConfigProperties(
+            new ByteArrayInputStream(yaml.getBytes(StandardCharsets.UTF_8)));
+    return new JaegerRemoteSamplerComponentProvider().create(config);
+  }
+}