Opamp first iteration completion (#2067)

buildSrc/build.gradle.kts

@@ -16,6 +16,7 @@ dependencies {
   implementation("net.ltgt.gradle:gradle-errorprone-plugin:4.3.0")
   implementation("net.ltgt.gradle:gradle-nullaway-plugin:2.2.0")
   implementation("org.owasp:dependency-check-gradle:12.1.3")
+  implementation("ru.vyarus.animalsniffer:ru.vyarus.animalsniffer.gradle.plugin:2.0.1")
 }
 
 spotless {

buildSrc/src/main/kotlin/otel.animalsniffer-conventions.gradle.kts

@@ -0,0 +1,19 @@
+import ru.vyarus.gradle.plugin.animalsniffer.AnimalSniffer
+
+plugins {
+  id("otel.java-conventions")
+  id("ru.vyarus.animalsniffer")
+}
+
+dependencies {
+  signature("com.toasttab.android:gummy-bears-api-21:0.12.0:coreLib@signature")
+}
+
+animalsniffer {
+  sourceSets = listOf(java.sourceSets.main.get())
+}
+
+// Always having declared output makes this task properly participate in tasks up-to-date checks
+tasks.withType<AnimalSniffer> {
+  reports.text.required.set(true)
+}

disk-buffering/build.gradle.kts

@@ -1,12 +1,11 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
-import ru.vyarus.gradle.plugin.animalsniffer.AnimalSniffer
 
 plugins {
   id("otel.java-conventions")
   id("otel.publish-conventions")
+  id("otel.animalsniffer-conventions")
   id("com.gradleup.shadow")
   id("me.champeau.jmh") version "0.7.3"
-  id("ru.vyarus.animalsniffer") version "2.0.1"
   id("com.squareup.wire") version "5.3.11"
 }
 
@@ -20,27 +19,12 @@ dependencies {
   implementation("io.opentelemetry:opentelemetry-api-incubator")
   compileOnly("com.google.auto.value:auto-value-annotations")
   annotationProcessor("com.google.auto.value:auto-value")
-  signature("com.toasttab.android:gummy-bears-api-21:0.12.0:coreLib@signature")
   testImplementation("org.mockito:mockito-inline")
   testImplementation("io.opentelemetry:opentelemetry-sdk-testing")
 
   protos("io.opentelemetry.proto:opentelemetry-proto:1.7.0-alpha@jar")
 }
 
-animalsniffer {
-  sourceSets = listOf(java.sourceSets.main.get())
-}
-
-// Always having declared output makes this task properly participate in tasks up-to-date checks
-tasks.withType<AnimalSniffer> {
-  reports.text.required.set(true)
-}
-
-// Attaching animalsniffer check to the compilation process.
-tasks.named("classes").configure {
-  finalizedBy("animalsnifferMain")
-}
-
 jmh {
   warmupIterations.set(0)
   fork.set(2)

opamp-client/README.md

@@ -3,6 +3,56 @@
 Java implementation of the OpAMP
 client [spec](https://github.com/open-telemetry/opamp-spec/blob/main/specification.md).
 
+> [!WARNING]
+> This is an incubating feature. Breaking changes can happen on a new release without previous
+> notice and without backward compatibility guarantees.
+
+## Usage
+
+```java
+// Initializing it
+
+RequestService requestService = HttpRequestService.create(OkHttpSender.create("[OPAMP_SERVICE_URL]"));
+// RequestService requestService = WebSocketRequestService.create(OkHttpWebSocket.create("[OPAMP_SERVICE_URL]")); // Use this instead to connect to the server via WebSocket.
+OpampClient client =
+    OpampClient.builder()
+        .putIdentifyingAttribute("service.name", "My service name")
+        .enableRemoteConfig()
+        .setRequestService(requestService)
+        .build(
+            new OpampClient.Callbacks() {
+              @Override
+              public void onConnect() {}
+
+              @Override
+              public void onConnectFailed(@Nullable Throwable throwable) {}
+
+              @Override
+              public void onErrorResponse(ServerErrorResponse errorResponse) {}
+
+              @Override
+              public void onMessage(MessageData messageData) {
+                AgentRemoteConfig remoteConfig = messageData.getRemoteConfig();
+                if (remoteConfig != null) {
+                  // A remote config was received
+
+                  // After applying it...
+                  client.setRemoteConfigStatus(
+                      new RemoteConfigStatus.Builder()
+                          .status(RemoteConfigStatuses.RemoteConfigStatuses_APPLIED)
+                          .build());
+                }
+              }
+            });
+
+// State update
+client.setAgentDescription(new AgentDescription.Builder().build());
+
+// App shutdown
+client.close();
+
+```
+
 ## Component owners
 
 - [Cesar Munoz](https://github.com/LikeTheSalad), Elastic

opamp-client/build.gradle.kts

@@ -4,6 +4,8 @@ import java.net.URL
 
 plugins {
   id("otel.java-conventions")
+  id("otel.publish-conventions")
+  id("otel.animalsniffer-conventions")
   id("de.undercouch.download") version "5.6.0"
   id("com.squareup.wire") version "5.3.11"
 }
@@ -14,6 +16,7 @@ otelJava.moduleName.set("io.opentelemetry.contrib.opamp.client")
 dependencies {
   implementation("com.squareup.okhttp3:okhttp")
   implementation("com.github.f4b6a3:uuid-creator")
+  implementation("io.opentelemetry:opentelemetry-api")
   annotationProcessor("com.google.auto.value:auto-value")
   compileOnly("com.google.auto.value:auto-value-annotations")
   testImplementation("org.mockito:mockito-inline")

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/OpampClient.java

@@ -6,45 +6,23 @@
 package io.opentelemetry.opamp.client.internal;
 
 import io.opentelemetry.opamp.client.internal.response.MessageData;
+import java.io.Closeable;
 import javax.annotation.Nullable;
 import opamp.proto.AgentDescription;
 import opamp.proto.RemoteConfigStatus;
 import opamp.proto.ServerErrorResponse;
 
-public interface OpampClient {
+public interface OpampClient extends Closeable {
 
   static OpampClientBuilder builder() {
     return new OpampClientBuilder();
   }
 
   /**
-   * Starts the client and begin attempts to connect to the Server. Once connection is established
+   * Sets attributes of the Agent. The attributes will be included in the next outgoing status
-   * the client will attempt to maintain it by reconnecting if the connection is lost. All failed
+   * report. This is typically used by Agents which allow their AgentDescription to change
-   * connection attempts will be reported via {@link Callbacks#onConnectFailed(Throwable)} callback.
+   * dynamically while the OpAMPClient is started. May be also called from {@link
-   *
+   * Callbacks#onMessage(MessageData)}.
-   * <p>This method does not wait until the connection to the Server is established and will likely
-   * return before the connection attempts are even made.
-   *
-   * <p>This method may be called only once.
-   *
-   * @param callbacks The Callback to which the Client will notify about any Server requests and
-   *     responses.
-   */
-  void start(Callbacks callbacks);
-
-  /**
-   * Stops the client. May be called only after {@link #start(Callbacks)}. May be called only once.
-   * After this call returns successfully it is guaranteed that no callbacks will be called. Once
-   * stopped, the client cannot be started again.
-   */
-  void stop();
-
-  /**
-   * Sets attributes of the Agent. The attributes will be included in the next status report sent to
-   * the Server. When called after {@link #start(Callbacks)}, the attributes will be included in the
-   * next outgoing status report. This is typically used by Agents which allow their
-   * AgentDescription to change dynamically while the OpAMPClient is started. May be also called
-   * from {@link Callbacks#onMessage(MessageData)}.
    *
    * @param agentDescription The new agent description.
    */
@@ -59,16 +37,14 @@ public interface OpampClient {
 
   interface Callbacks {
     /**
-     * Called when the connection is successfully established to the Server. May be called after
+     * Called when the connection is successfully established to the Server. For WebSocket clients
-     * {@link #start(Callbacks)} is called and every time a connection is established to the Server.
+     * this is called after the handshake is completed without any error. For HTTP clients this is
-     * For WebSocket clients this is called after the handshake is completed without any error. For
+     * called for any request if the response status is OK.
-     * HTTP clients this is called for any request if the response status is OK.
      */
     void onConnect();
 
     /**
-     * Called when the connection to the Server cannot be established. May be called after {@link
+     * Called when the connection to the Server cannot be established. May also be called if the
-     * #start(Callbacks)} is called and tries to connect to the Server. May also be called if the
      * connection is lost and reconnection attempt fails.
      *
      * @param throwable The exception.

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/OpampClientBuilder.java

@@ -381,11 +381,7 @@ public final class OpampClientBuilder {
     return this;
   }
 
-  public OpampClient build() {
+  public OpampClient build(OpampClient.Callbacks callbacks) {
-    if (service == null) {
-      throw new IllegalStateException(
-          "The request service is not set. You must provide it by calling setRequestService()");
-    }
     List<KeyValue> protoIdentifyingAttributes = new ArrayList<>();
     List<KeyValue> protoNonIdentifyingAttributes = new ArrayList<>();
     identifyingAttributes.forEach(
@@ -411,7 +407,7 @@ public final class OpampClientBuilder {
             new State.InstanceUid(instanceUid),
             new State.Flags(0L),
             effectiveConfigState);
-    return OpampClientImpl.create(service, state);
+    return OpampClientImpl.create(service, state, callbacks);
   }
 
   private static State.EffectiveConfig createEffectiveConfigNoop() {

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/connectivity/http/OkHttpSender.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.opamp.client.internal.connectivity.http;
 
+import io.opentelemetry.api.internal.InstrumentationUtil;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.concurrent.CompletableFuture;
@@ -13,6 +14,7 @@ import okhttp3.Call;
 import okhttp3.Callback;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
+import okhttp3.Request;
 import okhttp3.RequestBody;
 import okio.BufferedSink;
 
@@ -45,8 +47,16 @@ public final class OkHttpSender implements HttpSender {
     RequestBody body = new RawRequestBody(writer, contentLength, MEDIA_TYPE);
     builder.post(body);
 
+    // By suppressing instrumentations, we prevent automatic instrumentations for the okhttp request
+    // that polls the opamp server.
+    InstrumentationUtil.suppressInstrumentation(() -> doSendRequest(builder.build(), future));
+
+    return future;
+  }
+
+  private void doSendRequest(Request request, CompletableFuture<Response> future) {
     client
-        .newCall(builder.build())
+        .newCall(request)
         .enqueue(
             new Callback() {
               @Override
@@ -59,8 +69,6 @@ public final class OkHttpSender implements HttpSender {
                 future.completeExceptionally(e);
               }
             });
-
-    return future;
   }
 
   private static class OkHttpResponse implements Response {

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/OpampClientImpl.java

@@ -28,11 +28,9 @@ import io.opentelemetry.opamp.client.internal.state.State;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import okio.ByteString;
 import opamp.proto.AgentDescription;
 import opamp.proto.AgentToServer;
@@ -51,9 +49,8 @@ public final class OpampClientImpl
   private final AgentToServerAppenders appenders;
   private final OpampClientState state;
   private final RecipeManager recipeManager;
-  private final AtomicBoolean isRunning = new AtomicBoolean(false);
   private final AtomicBoolean hasStopped = new AtomicBoolean(false);
-  @Nullable private Callbacks callbacks;
+  private final Callbacks callbacks;
 
   /** Fields that must always be sent. */
   private static final List<Field> REQUIRED_FIELDS;
@@ -84,7 +81,8 @@ public final class OpampClientImpl
     COMPRESSABLE_FIELDS = Collections.unmodifiableList(compressableFields);
   }
 
-  public static OpampClientImpl create(RequestService requestService, OpampClientState state) {
+  public static OpampClientImpl create(
+      RequestService requestService, OpampClientState state, Callbacks callbacks) {
     AgentToServerAppenders appenders =
         new AgentToServerAppenders(
             AgentDescriptionAppender.create(state.agentDescription),
@@ -95,41 +93,35 @@ public final class OpampClientImpl
             InstanceUidAppender.create(state.instanceUid),
             FlagsAppender.create(state.flags),
             AgentDisconnectAppender.create());
-    return new OpampClientImpl(
+    OpampClientImpl client =
-        requestService, appenders, state, RecipeManager.create(REQUIRED_FIELDS));
+        new OpampClientImpl(
+            requestService, appenders, state, RecipeManager.create(REQUIRED_FIELDS), callbacks);
+
+    // Start
+    requestService.start(client, client);
+    client.disableCompression();
+    client.startObservingStateChange();
+    requestService.sendRequest();
+
+    return client;
   }
 
   private OpampClientImpl(
       RequestService requestService,
       AgentToServerAppenders appenders,
       OpampClientState state,
-      RecipeManager recipeManager) {
+      RecipeManager recipeManager,
+      Callbacks callbacks) {
     this.requestService = requestService;
     this.appenders = appenders;
     this.state = state;
     this.recipeManager = recipeManager;
-  }
-
-  @Override
-  public void start(@Nonnull Callbacks callbacks) {
-    if (hasStopped.get()) {
-      throw new IllegalStateException("The client cannot start after it has been stopped.");
-    }
-    if (isRunning.compareAndSet(false, true)) {
     this.callbacks = callbacks;
-      requestService.start(this, this);
-      disableCompression();
-      startObservingStateChange();
-      requestService.sendRequest();
-    } else {
-      throw new IllegalStateException("The client has already been started");
-    }
   }
 
   @Override
-  public void stop() {
+  public void close() {
-    if (isRunning.compareAndSet(true, false)) {
+    if (hasStopped.compareAndSet(false, true)) {
-      hasStopped.set(true);
       stopObservingStateChange();
       prepareDisconnectRequest();
       requestService.stop();
@@ -154,12 +146,12 @@ public final class OpampClientImpl
 
   @Override
   public void onConnectionSuccess() {
-    getCallbacks().onConnect();
+    callbacks.onConnect();
   }
 
   @Override
   public void onConnectionFailed(Throwable throwable) {
-    getCallbacks().onConnectFailed(throwable);
+    callbacks.onConnectFailed(throwable);
   }
 
   @Override
@@ -176,7 +168,7 @@ public final class OpampClientImpl
     preserveFailedRequestRecipe();
     if (throwable instanceof OpampServerResponseException) {
       ServerErrorResponse errorResponse = ((OpampServerResponseException) throwable).errorResponse;
-      getCallbacks().onErrorResponse(errorResponse);
+      callbacks.onErrorResponse(errorResponse);
     }
   }
 
@@ -203,7 +195,7 @@ public final class OpampClientImpl
     }
 
     if (notifyOnMessage) {
-      getCallbacks().onMessage(messageBuilder.build());
+      callbacks.onMessage(messageBuilder.build());
     }
   }
 
@@ -224,11 +216,6 @@ public final class OpampClientImpl
     recipeManager.next().addField(Field.AGENT_DISCONNECT);
   }
 
-  @Nonnull
-  private Callbacks getCallbacks() {
-    return Objects.requireNonNull(callbacks);
-  }
-
   @Override
   public Request get() {
     AgentToServer.Builder builder = new AgentToServer.Builder();

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/request/delay/ExponentialBackoffPeriodicDelay.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.opamp.client.internal.request.delay;
+
+import java.time.Duration;
+import javax.annotation.concurrent.GuardedBy;
+
+public final class ExponentialBackoffPeriodicDelay implements PeriodicDelay {
+  private final Duration initialDelay;
+  private final Object delayNanosLock = new Object();
+
+  @GuardedBy("delayNanosLock")
+  private long delayNanos;
+
+  public ExponentialBackoffPeriodicDelay(Duration initialDelay) {
+    this.initialDelay = initialDelay;
+    delayNanos = initialDelay.toNanos();
+  }
+
+  @Override
+  public Duration getNextDelay() {
+    synchronized (delayNanosLock) {
+      long previousValue = delayNanos;
+      delayNanos = delayNanos * 2;
+      return Duration.ofNanos(previousValue);
+    }
+  }
+
+  @Override
+  public void reset() {
+    synchronized (delayNanosLock) {
+      delayNanos = initialDelay.toNanos();
+    }
+  }
+}

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/request/delay/RetryPeriodicDelay.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.opamp.client.internal.request.delay;
+
+import java.time.Duration;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicReference;
+
+/** Defaults to an exponential backoff strategy, unless a delay is suggested. */
+public final class RetryPeriodicDelay implements PeriodicDelay, AcceptsDelaySuggestion {
+  private final ExponentialBackoffPeriodicDelay exponentialBackoff;
+  private final AtomicReference<PeriodicDelay> currentDelay;
+
+  public static RetryPeriodicDelay create(Duration initialDelay) {
+    return new RetryPeriodicDelay(new ExponentialBackoffPeriodicDelay(initialDelay));
+  }
+
+  private RetryPeriodicDelay(ExponentialBackoffPeriodicDelay exponentialBackoff) {
+    this.exponentialBackoff = exponentialBackoff;
+    currentDelay = new AtomicReference<>(exponentialBackoff);
+  }
+
+  @Override
+  public void suggestDelay(Duration delay) {
+    currentDelay.set(PeriodicDelay.ofFixedDuration(delay));
+  }
+
+  @Override
+  public Duration getNextDelay() {
+    return Objects.requireNonNull(currentDelay.get()).getNextDelay();
+  }
+
+  @Override
+  public void reset() {
+    exponentialBackoff.reset();
+    currentDelay.set(exponentialBackoff);
+  }
+}

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/request/service/HttpRequestService.java

@@ -11,6 +11,7 @@ import io.opentelemetry.opamp.client.internal.connectivity.http.RetryAfterParser
 import io.opentelemetry.opamp.client.internal.request.Request;
 import io.opentelemetry.opamp.client.internal.request.delay.AcceptsDelaySuggestion;
 import io.opentelemetry.opamp.client.internal.request.delay.PeriodicDelay;
+import io.opentelemetry.opamp.client.internal.request.delay.RetryPeriodicDelay;
 import io.opentelemetry.opamp.client.internal.response.OpampServerResponseException;
 import io.opentelemetry.opamp.client.internal.response.Response;
 import java.io.IOException;
@@ -47,6 +48,8 @@ public final class HttpRequestService implements RequestService {
   @Nullable private Supplier<Request> requestSupplier;
   public static final PeriodicDelay DEFAULT_DELAY_BETWEEN_REQUESTS =
       PeriodicDelay.ofFixedDuration(Duration.ofSeconds(30));
+  public static final PeriodicDelay DEFAULT_DELAY_BETWEEN_RETRIES =
+      RetryPeriodicDelay.create(Duration.ofSeconds(30));
 
   /**
    * Creates an {@link HttpRequestService}.
@@ -54,7 +57,7 @@ public final class HttpRequestService implements RequestService {
    * @param requestSender The HTTP sender implementation.
    */
   public static HttpRequestService create(HttpSender requestSender) {
-    return create(requestSender, DEFAULT_DELAY_BETWEEN_REQUESTS, DEFAULT_DELAY_BETWEEN_REQUESTS);
+    return create(requestSender, DEFAULT_DELAY_BETWEEN_REQUESTS, DEFAULT_DELAY_BETWEEN_RETRIES);
   }
 
   /**

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/request/service/WebSocketRequestService.java

@@ -10,6 +10,7 @@ import io.opentelemetry.opamp.client.internal.connectivity.websocket.WebSocket;
 import io.opentelemetry.opamp.client.internal.request.Request;
 import io.opentelemetry.opamp.client.internal.request.delay.AcceptsDelaySuggestion;
 import io.opentelemetry.opamp.client.internal.request.delay.PeriodicDelay;
+import io.opentelemetry.opamp.client.internal.request.delay.RetryPeriodicDelay;
 import io.opentelemetry.opamp.client.internal.response.OpampServerResponseException;
 import io.opentelemetry.opamp.client.internal.response.Response;
 import java.io.ByteArrayOutputStream;
@@ -30,7 +31,7 @@ import opamp.proto.ServerToAgent;
 
 public final class WebSocketRequestService implements RequestService, WebSocket.Listener {
   private static final PeriodicDelay DEFAULT_DELAY_BETWEEN_RETRIES =
-      PeriodicDelay.ofFixedDuration(Duration.ofSeconds(30));
+      RetryPeriodicDelay.create(Duration.ofSeconds(30));
 
   private final WebSocket webSocket;
   private final AtomicBoolean isRunning = new AtomicBoolean(false);

opamp-client/src/test/java/io/opentelemetry/opamp/client/internal/impl/OpampClientImplTest.java

@@ -6,7 +6,6 @@
 package io.opentelemetry.opamp.client.internal.impl;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.fail;
 import static org.awaitility.Awaitility.await;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.never;
@@ -90,7 +89,7 @@ class OpampClientImplTest {
 
   @AfterEach
   void tearDown() {
-    client.stop();
+    client.close();
   }
 
   @Test
@@ -178,23 +177,12 @@ class OpampClientImplTest {
     initializeClient();
 
     enqueueServerToAgentResponse(new ServerToAgent.Builder().build());
-    client.stop();
+    client.close();
 
     AgentToServer agentToServerMessage = getAgentToServerMessage(takeRequest());
     assertThat(agentToServerMessage.agent_disconnect).isNotNull();
   }
 
-  @Test
-  void verifyStartOnlyOnce() {
-    initializeClient();
-    try {
-      client.start(callbacks);
-      fail("Should have thrown an exception");
-    } catch (IllegalStateException e) {
-      assertThat(e).hasMessage("The client has already been started");
-    }
-  }
-
   @Test
   void onSuccess_withChangesToReport_notifyCallbackOnMessage() {
     initializeClient();
@@ -403,13 +391,12 @@ class OpampClientImplTest {
   }
 
   private RecordedRequest initializeClient(ServerToAgent initialResponse) {
-    client = OpampClientImpl.create(requestService, state);
-
     // Prepare first request on start
     enqueueServerToAgentResponse(initialResponse);
 
     callbacks = spy(new TestCallbacks());
-    client.start(callbacks);
+    client = OpampClientImpl.create(requestService, state, callbacks);
+
     return takeRequest();
   }
 

opamp-client/src/test/java/io/opentelemetry/opamp/client/internal/request/delay/ExponentialBackoffPeriodicDelayTest.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.opamp.client.internal.request.delay;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Duration;
+import org.junit.jupiter.api.Test;
+
+class ExponentialBackoffPeriodicDelayTest {
+  @Test
+  void verifyDelayUpdates() {
+    ExponentialBackoffPeriodicDelay delay =
+        new ExponentialBackoffPeriodicDelay(Duration.ofSeconds(1));
+
+    assertThat(delay.getNextDelay()).isEqualTo(Duration.ofSeconds(1));
+    assertThat(delay.getNextDelay()).isEqualTo(Duration.ofSeconds(2));
+    assertThat(delay.getNextDelay()).isEqualTo(Duration.ofSeconds(4));
+    assertThat(delay.getNextDelay()).isEqualTo(Duration.ofSeconds(8));
+    assertThat(delay.getNextDelay()).isEqualTo(Duration.ofSeconds(16));
+
+    // Reset
+    delay.reset();
+    assertThat(delay.getNextDelay()).isEqualTo(Duration.ofSeconds(1));
+  }
+}

opamp-client/src/test/java/io/opentelemetry/opamp/client/internal/request/delay/RetryPeriodicDelayTest.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.opamp.client.internal.request.delay;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Duration;
+import org.junit.jupiter.api.Test;
+
+class RetryPeriodicDelayTest {
+  @Test
+  public void verifyDelayBehavior() {
+    RetryPeriodicDelay retryPeriodicDelay = RetryPeriodicDelay.create(Duration.ofSeconds(1));
+
+    // Without suggested delay
+    assertThat(retryPeriodicDelay.getNextDelay()).isEqualTo(Duration.ofSeconds(1));
+    assertThat(retryPeriodicDelay.getNextDelay()).isEqualTo(Duration.ofSeconds(2));
+    assertThat(retryPeriodicDelay.getNextDelay()).isEqualTo(Duration.ofSeconds(4));
+    retryPeriodicDelay.reset();
+    assertThat(retryPeriodicDelay.getNextDelay()).isEqualTo(Duration.ofSeconds(1));
+
+    // With suggested delay
+    retryPeriodicDelay.suggestDelay(Duration.ofSeconds(5));
+    assertThat(retryPeriodicDelay.getNextDelay()).isEqualTo(Duration.ofSeconds(5));
+    retryPeriodicDelay.reset();
+    assertThat(retryPeriodicDelay.getNextDelay()).isEqualTo(Duration.ofSeconds(1));
+  }
+}