Add ADAPTIVE_V2 retry mode to support the legacy behavior

core/aws-core/src/main/java/software/amazon/awssdk/awscore/retry/AwsRetryStrategy.java

@@ -18,6 +18,7 @@
 import software.amazon.awssdk.annotations.SdkPublicApi;
 import software.amazon.awssdk.awscore.exception.AwsServiceException;
 import software.amazon.awssdk.awscore.internal.AwsErrorCode;
+import software.amazon.awssdk.core.internal.retry.RetryPolicyAdapter;
 import software.amazon.awssdk.core.internal.retry.SdkDefaultRetryStrategy;
 import software.amazon.awssdk.core.retry.RetryMode;
 import software.amazon.awssdk.retries.AdaptiveRetryStrategy;
@@ -54,10 +55,12 @@ private AwsRetryStrategy() {
         switch (mode) {
             case STANDARD:
                 return standardRetryStrategy();
-            case ADAPTIVE:
+            case ADAPTIVE_V2:
                 return adaptiveRetryStrategy();
             case LEGACY:
                 return legacyRetryStrategy();
+            case ADAPTIVE:
+                return legacyAdaptiveRetryStrategy();
             default:
                 throw new IllegalArgumentException("unknown retry mode: " + mode);
         }
@@ -84,7 +87,6 @@ private AwsRetryStrategy() {
         return DefaultRetryStrategy.none();
     }
 
-
     /**
      * Returns a {@link StandardRetryStrategy} with AWS-specific conditions added.
      *
@@ -121,8 +123,8 @@ public static AdaptiveRetryStrategy adaptiveRetryStrategy() {
      * Configures a retry strategy using its builder to add AWS-specific retry exceptions.
      *
      * @param builder The builder to add the AWS-specific retry exceptions
+     * @param <T>     The type of the builder extending {@link RetryStrategy.Builder}
      * @return The given builder
-     * @param <T> The type of the builder extending {@link RetryStrategy.Builder}
      */
     public static <T extends RetryStrategy.Builder<T, ?>> T configure(T builder) {
         return builder.retryOnException(AwsRetryStrategy::retryOnAwsRetryableErrors);
@@ -135,6 +137,9 @@ public static AdaptiveRetryStrategy adaptiveRetryStrategy() {
      * @return The given builder
      */
     public static RetryStrategy.Builder<?, ?> configureStrategy(RetryStrategy.Builder<?, ?> builder) {
+        if (builder instanceof RetryPolicyAdapter.Builder) {
+            return builder;
+        }
         return builder.retryOnException(AwsRetryStrategy::retryOnAwsRetryableErrors);
     }
 
@@ -145,4 +150,16 @@ private static boolean retryOnAwsRetryableErrors(Throwable ex) {
         }
         return false;
     }
+
+    /**
+     * Returns a {@link RetryStrategy<?, ?>} that implements the legacy {@link RetryMode#ADAPTIVE} mode.
+     *
+     * @return a {@link RetryStrategy<?, ?>} that implements the legacy {@link RetryMode#ADAPTIVE} mode.
+     */
+    private static RetryStrategy<?, ?> legacyAdaptiveRetryStrategy() {
+        return RetryPolicyAdapter.builder()
+                                 .retryPolicy(AwsRetryPolicy.forRetryMode(RetryMode.ADAPTIVE))
+                                 .build();
+    }
+
 }

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/http/pipeline/stages/utils/RetryableStageHelper2.java

@@ -60,7 +60,6 @@ public final class RetryableStageHelper2 {
     public static final String SDK_RETRY_INFO_HEADER = "amz-sdk-request";
     private final SdkHttpFullRequest request;
     private final RequestExecutionContext context;
-    private final RetryPolicy retryPolicy;
     private RetryPolicyAdapter retryPolicyAdapter;
     private final RetryStrategy<?, ?> retryStrategy;
     private final HttpClientDependencies dependencies;
@@ -74,8 +73,16 @@ public RetryableStageHelper2(SdkHttpFullRequest request,
                                  HttpClientDependencies dependencies) {
         this.request = request;
         this.context = context;
-        this.retryPolicy = dependencies.clientConfiguration().option(SdkClientOption.RETRY_POLICY);
-        this.retryStrategy = dependencies.clientConfiguration().option(SdkClientOption.RETRY_STRATEGY);
+        RetryPolicy retryPolicy = dependencies.clientConfiguration().option(SdkClientOption.RETRY_POLICY);
+        RetryStrategy<?, ?> retryStrategy = dependencies.clientConfiguration().option(SdkClientOption.RETRY_STRATEGY);
+        if (retryPolicy != null) {
+            retryPolicyAdapter = RetryPolicyAdapter.builder()
+                                                   .retryPolicy(retryPolicy)
+                                                   .build();
+        } else if (retryStrategy instanceof RetryPolicyAdapter) {
+            retryPolicyAdapter = (RetryPolicyAdapter) retryStrategy;
+        }
+        this.retryStrategy = retryStrategy;
         this.dependencies = dependencies;
     }
 
@@ -256,15 +263,14 @@ private int retriesAttemptedSoFar() {
      * calling code.
      */
     private RetryStrategy<?, ?> retryStrategy() {
-        if (retryPolicy != null) {
-            if (retryPolicyAdapter == null) {
-                retryPolicyAdapter = RetryPolicyAdapter.builder()
-                                                       .retryPolicy(this.retryPolicy)
+        if (retryPolicyAdapter != null) {
+            if (retryPolicyAdapter.isInitialized()) {
+                retryPolicyAdapter = retryPolicyAdapter.toBuilder()
                                                        .retryPolicyContext(retryPolicyContext())
                                                        .build();
             } else {
                 retryPolicyAdapter = retryPolicyAdapter.toBuilder()
-                                                       .retryPolicyContext(retryPolicyContext())
+                                                       .initialize(retryPolicyContext())
                                                        .build();
             }
             return retryPolicyAdapter;

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/retry/RetryPolicyAdapter.java

@@ -42,25 +42,26 @@
  */
 @SdkInternalApi
 public final class RetryPolicyAdapter implements RetryStrategy<RetryPolicyAdapter.Builder, RetryPolicyAdapter> {
-
     private final RetryPolicy retryPolicy;
     private final RetryPolicyContext retryPolicyContext;
     private final RateLimitingTokenBucket rateLimitingTokenBucket;
 
     private RetryPolicyAdapter(Builder builder) {
         this.retryPolicy = Validate.paramNotNull(builder.retryPolicy, "retryPolicy");
-        this.retryPolicyContext = Validate.paramNotNull(builder.retryPolicyContext, "retryPolicyContext");
+        this.retryPolicyContext = builder.retryPolicyContext;
         this.rateLimitingTokenBucket = builder.rateLimitingTokenBucket;
     }
 
     @Override
     public AcquireInitialTokenResponse acquireInitialToken(AcquireInitialTokenRequest request) {
+        validateState();
         RetryPolicyAdapterToken token = new RetryPolicyAdapterToken(request.scope());
         return AcquireInitialTokenResponse.create(token, rateLimitingTokenAcquire());
     }
 
     @Override
     public RefreshRetryTokenResponse refreshRetryToken(RefreshRetryTokenRequest request) {
+        validateState();
         RetryPolicyAdapterToken token = getToken(request.token());
         boolean willRetry = retryPolicy.aggregateRetryCondition().shouldRetry(retryPolicyContext);
         if (!willRetry) {
@@ -73,6 +74,7 @@ public RefreshRetryTokenResponse refreshRetryToken(RefreshRetryTokenRequest requ
 
     @Override
     public RecordSuccessResponse recordSuccess(RecordSuccessRequest request) {
+        validateState();
         RetryPolicyAdapterToken token = getToken(request.token());
         retryPolicy.aggregateRetryCondition().requestSucceeded(retryPolicyContext);
         return RecordSuccessResponse.create(token);
@@ -88,6 +90,16 @@ public Builder toBuilder() {
         return new Builder(this);
     }
 
+    public boolean isInitialized() {
+        return retryPolicyContext != null;
+    }
+
+    void validateState() {
+        if (retryPolicyContext == null) {
+            throw new IllegalStateException("This RetryPolicyAdapter instance has not been initialized.");
+        }
+    }
+
     RetryPolicyAdapterToken getToken(RetryToken token) {
         return Validate.isInstanceOf(RetryPolicyAdapterToken.class, token, "Object of class %s was not created by this retry "
                                                                            + "strategy", token.getClass().getName());
@@ -146,7 +158,6 @@ public static class Builder implements RetryStrategy.Builder<RetryPolicyAdapter.
         private RateLimitingTokenBucket rateLimitingTokenBucket;
 
         private Builder() {
-            rateLimitingTokenBucket = new RateLimitingTokenBucket();
         }
 
         private Builder(RetryPolicyAdapter adapter) {
@@ -162,7 +173,7 @@ public Builder retryOnException(Predicate<Throwable> shouldRetry) {
 
         @Override
         public Builder maxAttempts(int maxAttempts) {
-            throw new UnsupportedOperationException("RetryPolicyAdapter does not support calling retryOnException");
+            throw new UnsupportedOperationException("RetryPolicyAdapter does not support calling maxAttempts");
         }
 
         @Override
@@ -175,13 +186,14 @@ public Builder retryPolicy(RetryPolicy retryPolicy) {
             return this;
         }
 
-        public Builder rateLimitingTokenBucket(RateLimitingTokenBucket rateLimitingTokenBucket) {
-            this.rateLimitingTokenBucket = rateLimitingTokenBucket;
+        public Builder retryPolicyContext(RetryPolicyContext retryPolicyContext) {
+            this.retryPolicyContext = retryPolicyContext;
             return this;
         }
 
-        public Builder retryPolicyContext(RetryPolicyContext retryPolicyContext) {
+        public Builder initialize(RetryPolicyContext retryPolicyContext) {
             this.retryPolicyContext = retryPolicyContext;
+            this.rateLimitingTokenBucket = new RateLimitingTokenBucket();
             return this;
         }
 

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/retry/SdkDefaultRetryStrategy.java

@@ -19,6 +19,7 @@
 import software.amazon.awssdk.core.exception.SdkException;
 import software.amazon.awssdk.core.exception.SdkServiceException;
 import software.amazon.awssdk.core.retry.RetryMode;
+import software.amazon.awssdk.core.retry.RetryPolicy;
 import software.amazon.awssdk.core.retry.RetryUtils;
 import software.amazon.awssdk.retries.AdaptiveRetryStrategy;
 import software.amazon.awssdk.retries.DefaultRetryStrategy;
@@ -55,6 +56,8 @@ private SdkDefaultRetryStrategy() {
             case STANDARD:
                 return standardRetryStrategy();
             case ADAPTIVE:
+                return legacyAdaptiveRetryStrategy();
+            case ADAPTIVE_V2:
                 return adaptiveRetryStrategy();
             case LEGACY:
                 return legacyRetryStrategy();
@@ -74,11 +77,14 @@ public static RetryMode retryMode(RetryStrategy<?, ?> retryStrategy) {
             return RetryMode.STANDARD;
         }
         if (retryStrategy instanceof AdaptiveRetryStrategy) {
-            return RetryMode.ADAPTIVE;
+            return RetryMode.ADAPTIVE_V2;
         }
         if (retryStrategy instanceof LegacyRetryStrategy) {
             return RetryMode.LEGACY;
         }
+        if (retryStrategy instanceof RetryPolicyAdapter) {
+            return RetryMode.ADAPTIVE;
+        }
         throw new IllegalArgumentException("unknown retry strategy class: " + retryStrategy.getClass().getName());
     }
 
@@ -193,4 +199,16 @@ private static boolean retryOnThrottlingCondition(Throwable ex) {
         }
         return false;
     }
+
+    /**
+     * Returns a {@link RetryStrategy<?, ?>} that implements the legacy {@link RetryMode#ADAPTIVE} mode.
+     *
+     * @return a {@link RetryStrategy<?, ?>} that implements the legacy {@link RetryMode#ADAPTIVE} mode.
+     */
+    private static RetryStrategy<?, ?> legacyAdaptiveRetryStrategy() {
+        return RetryPolicyAdapter.builder()
+                                 .retryPolicy(RetryPolicy.forRetryMode(RetryMode.ADAPTIVE))
+                                 .build();
+    }
 }
+

core/sdk-core/src/main/java/software/amazon/awssdk/core/retry/RetryMode.java

@@ -73,7 +73,7 @@ public enum RetryMode {
     STANDARD,
 
     /**
-     * Adaptive retry mode builds on {@code STANDARD} mode.
+     * Adaptive retry mode builds on {@link #STANDARD} mode.
      * <p>
      * Adaptive retry mode dynamically limits the rate of AWS requests to maximize success rate. This may be at the
      * expense of request latency. Adaptive retry mode is not recommended when predictable latency is important.
@@ -84,9 +84,31 @@ public enum RetryMode {
      * the same client. When using adaptive retry mode, we recommend using a single client per resource.
      *
      * @see RetryPolicy#isFastFailRateLimiting()
+     * @deprecated As of 2.25.xx, replaced by {@link #ADAPTIVE_V2}. The ADAPTIVE implementation has a bug that prevents it
+     * from remembering its state across requests which is needed to correctly estimate its sending rate. Given that
+     * this bug has been present since its introduction and that correct version might change the traffic patterns of the SDK we
+     * deemed too risky to fix this implementation.
      */
+    @Deprecated
     ADAPTIVE,
 
+    /**
+     * Adaptive V2 retry mode builds on {@link #STANDARD} mode.
+     * <p>
+     * Adaptive retry mode qdynamically limits the rate of AWS requests to maximize success rate. This may be at the
+     * expense of request latency. Adaptive V2 retry mode is not recommended when predictable latency is important.
+     * <p>
+     * {@code ADAPTIVE_V2} mode differs from {@link #ADAPTIVE} mode in the computed delays between calls, including the first 
+     * attempt
+     * that might be delayed if the algorithm considers that it's needed to increase the odds of a successful response.
+     * <p>
+     * <b>Warning:</b> Adaptive V2 retry mode assumes that the client is working against a single resource (e.g. one
+     * DynamoDB Table or one S3 Bucket). If you use a single client for multiple resources, throttling or outages
+     * associated with one resource will result in increased latency and failures when accessing all other resources via
+     * the same client. When using adaptive retry mode, we recommend using a single client per resource.
+     */
+    ADAPTIVE_V2,
+
     ;
 
     /**
@@ -176,6 +198,8 @@ private static Optional<RetryMode> fromString(String string) {
                     return Optional.of(STANDARD);
                 case "adaptive":
                     return Optional.of(ADAPTIVE);
+                case "adaptive_v2":
+                    return Optional.of(ADAPTIVE_V2);
                 default:
                     throw new IllegalStateException("Unsupported retry policy mode configured: " + string);
             }

core/sdk-core/src/main/java/software/amazon/awssdk/core/retry/RetryPolicy.java

@@ -372,6 +372,10 @@ private static final class BuilderImpl implements Builder {
         private Boolean fastFailRateLimiting;
 
         private BuilderImpl(RetryMode retryMode) {
+            if (retryMode == RetryMode.ADAPTIVE_V2) {
+                throw new UnsupportedOperationException("ADAPTIVE_V2 is not supported by retry policies, use a RetryStrategy "
+                                                        + "instead");
+            }
             this.retryMode = retryMode;
             this.numRetries = SdkDefaultRetrySetting.maxAttempts(retryMode) - 1;
             this.additionalRetryConditionsAllowed = true;

services/dynamodb/src/main/java/software/amazon/awssdk/services/dynamodb/DynamoDbRetryPolicy.java

@@ -23,6 +23,7 @@
 import software.amazon.awssdk.awscore.retry.AwsRetryStrategy;
 import software.amazon.awssdk.core.client.config.SdkClientConfiguration;
 import software.amazon.awssdk.core.client.config.SdkClientOption;
+import software.amazon.awssdk.core.internal.retry.RetryPolicyAdapter;
 import software.amazon.awssdk.core.internal.retry.SdkDefaultRetrySetting;
 import software.amazon.awssdk.core.retry.RetryMode;
 import software.amazon.awssdk.core.retry.RetryPolicy;
@@ -76,18 +77,8 @@ public static RetryPolicy resolveRetryPolicy(SdkClientConfiguration config) {
             return configuredRetryPolicy;
         }
 
-        RetryMode retryMode = RetryMode.resolver()
-                                       .profileFile(config.option(SdkClientOption.PROFILE_FILE_SUPPLIER))
-                                       .profileName(config.option(SdkClientOption.PROFILE_NAME))
-                                       .defaultRetryMode(config.option(SdkClientOption.DEFAULT_RETRY_MODE))
-                                       .resolve();
-
-        return AwsRetryPolicy.forRetryMode(retryMode)
-                             .toBuilder()
-                             .additionalRetryConditionsAllowed(false)
-                             .numRetries(MAX_ERROR_RETRY)
-                             .backoffStrategy(BACKOFF_STRATEGY)
-                             .build();
+        RetryMode retryMode = resolveRetryMode(config);
+        return retryPolicyFor(retryMode);
     }
 
     public static RetryStrategy<?, ?> resolveRetryStrategy(SdkClientConfiguration config) {
@@ -96,16 +87,35 @@ public static RetryPolicy resolveRetryPolicy(SdkClientConfiguration config) {
             return configuredRetryStrategy;
         }
 
-        RetryMode retryMode = RetryMode.resolver()
-                                       .profileFile(config.option(SdkClientOption.PROFILE_FILE_SUPPLIER))
-                                       .profileName(config.option(SdkClientOption.PROFILE_NAME))
-                                       .defaultRetryMode(config.option(SdkClientOption.DEFAULT_RETRY_MODE))
-                                       .resolve();
+        RetryMode retryMode = resolveRetryMode(config);
+
+        if (retryMode == RetryMode.ADAPTIVE) {
+            return RetryPolicyAdapter.builder()
+                                     .retryPolicy(retryPolicyFor(retryMode))
+                                     .build();
+        }
 
         return AwsRetryStrategy.forRetryMode(retryMode)
             .toBuilder()
             .maxAttempts(MAX_ATTEMPTS)
             .backoffStrategy(exponentialDelay(BASE_DELAY, SdkDefaultRetrySetting.MAX_BACKOFF))
             .build();
     }
+
+    private static RetryPolicy retryPolicyFor(RetryMode retryMode) {
+        return AwsRetryPolicy.forRetryMode(retryMode)
+                             .toBuilder()
+                             .additionalRetryConditionsAllowed(false)
+                             .numRetries(MAX_ERROR_RETRY)
+                             .backoffStrategy(BACKOFF_STRATEGY)
+                             .build();
+    }
+
+    private static RetryMode resolveRetryMode(SdkClientConfiguration config) {
+        return RetryMode.resolver()
+                        .profileFile(config.option(SdkClientOption.PROFILE_FILE_SUPPLIER))
+                        .profileName(config.option(SdkClientOption.PROFILE_NAME))
+                        .defaultRetryMode(config.option(SdkClientOption.DEFAULT_RETRY_MODE))
+                        .resolve();
+    }
 }