Return RetriableRequestException for Netty Max Active Stream error

CHANGELOG.md

@@ -14,6 +14,9 @@ and what APIs have changed, if applicable.
 
 ## [Unreleased]
 
+## [29.55.0] - 2024-05-23
+- Allow HttpBridge to return RetriableRequestException for the Netty max active stream error 
+
 ## [29.54.0] - 2024-05-08
 - Dual read monitors cluster uris similarity
 
@@ -5689,7 +5692,8 @@ patch operations can re-use these classes for generating patch messages.
 
 ## [0.14.1]
 
-[Unreleased]: https://github.com/linkedin/rest.li/compare/v29.54.0...master
+[Unreleased]: https://github.com/linkedin/rest.li/compare/v29.55.0...master
+[29.55.0]: https://github.com/linkedin/rest.li/compare/v29.54.0...v29.55.0
 [29.54.0]: https://github.com/linkedin/rest.li/compare/v29.53.1...v29.54.0
 [29.53.1]: https://github.com/linkedin/rest.li/compare/v29.53.0...v29.53.1
 [29.53.0]: https://github.com/linkedin/rest.li/compare/v29.52.1...v29.53.0

gradle.properties

@@ -1,4 +1,4 @@
-version=29.54.0
+version=29.55.0
 group=com.linkedin.pegasus
 org.gradle.configureondemand=true
 org.gradle.parallel=true

r2-core/build.gradle

@@ -5,6 +5,7 @@ dependencies {
   compile externalDependency.servletApi
   compile externalDependency.mail
   compile externalDependency.javaxActivation
+  compile externalDependency.netty
   testCompile project(':r2-testutils')
   testCompile project(':test-util')
   testCompile externalDependency.testng

r2-core/src/main/java/com/linkedin/r2/transport/http/common/HttpBridge.java

@@ -19,6 +19,7 @@
 
 
 import com.linkedin.r2.RemoteInvocationException;
+import com.linkedin.r2.RetriableRequestException;
 import com.linkedin.r2.message.Request;
 import com.linkedin.r2.message.rest.RestException;
 import com.linkedin.r2.message.rest.RestRequest;
@@ -32,6 +33,7 @@
 import com.linkedin.r2.transport.common.bridge.common.TransportResponse;
 import com.linkedin.r2.transport.common.bridge.common.TransportResponseImpl;
 
+import io.netty.handler.codec.http2.Http2Exception;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Map;
@@ -42,6 +44,9 @@
  */
 public class HttpBridge
 {
+  public static final String NETTY_MAX_ACTIVE_STREAM_ERROR_MESSAGE =
+      "Maximum active streams violated for this endpoint";
+
   /**
    * Wrap application callback for incoming RestResponse with a "generic" HTTP callback.
    *
@@ -132,6 +137,8 @@ public void onResponse(TransportResponse<RestResponse> response)
 
   /**
    * Wrap application callback for incoming StreamResponse with a "generic" HTTP callback.
+   * If callback returns the error which is in Netty Http2Exception.StreamException type,
+   * populate RetriableRequestException instead of RemoteInvocationException.
    *
    * @param callback the callback to receive the incoming RestResponse
    * @param request the request, used only to provide useful context in case an error
@@ -149,11 +156,12 @@ public void onResponse(TransportResponse<StreamResponse> response)
       {
         if (response.hasError())
         {
+          Throwable responseError = response.getError();
+          // If the error is due to the netty max active stream error, wrap it with RetriableRequestException instead
+          RemoteInvocationException exception =
+              wrapResponseError("Failed to get response from server for URI " + uri, responseError);
           response =
-              TransportResponseImpl.error(new RemoteInvocationException("Failed to get response from server for URI "
-                                                                            + uri,
-                                                                        response.getError()),
-                                          response.getWireAttributes());
+              TransportResponseImpl.error(exception, response.getWireAttributes());
         }
         else if (!RestStatus.isOK(response.getResponse().getStatus()))
         {
@@ -209,6 +217,35 @@ public void onResponse(TransportResponse<StreamResponse> response)
     };
   }
 
+  /**
+   * Check if the error is due to the netty max active stream error.
+   * @param responseError Throwable error to check
+   * @return True if the error is due to the netty max active stream error, false otherwise
+   */
+  private static boolean shouldReturnRetriableRequestException(Throwable responseError)
+  {
+    return responseError instanceof Http2Exception.StreamException
+        && responseError.getMessage().contains(NETTY_MAX_ACTIVE_STREAM_ERROR_MESSAGE);
+  }
+
+  /**
+   * Wrap the response error with the appropriate exception type.
+   * If the error is due to the netty max active stream, wrap it with RetriableRequestException.
+   * @param errorMessage Error message to wrap
+   * @param responseError Throwable error to wrap
+   * @return RemoteInvocationException or RetriableRequestException
+   */
+  private static RemoteInvocationException wrapResponseError(String errorMessage, Throwable responseError) {
+    if (shouldReturnRetriableRequestException(responseError))
+    {
+      return new RetriableRequestException(errorMessage, responseError);
+    }
+    else
+    {
+      return new RemoteInvocationException(errorMessage, responseError);
+    }
+  }
+
   /**
    * Gets the URI to display in exception messages. The query parameters part of the URI is omitted to prevent
    * displaying sensitive information.

r2-core/src/test/java/test/r2/transport/http/common/TestHttpBridge.java

@@ -20,6 +20,9 @@
 
 package test.r2.transport.http.common;
 
+import com.linkedin.r2.RetriableRequestException;
+import io.netty.handler.codec.http2.Http2Error;
+import io.netty.handler.codec.http2.Http2Exception;
 import java.net.URI;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
@@ -43,13 +46,18 @@
 import com.linkedin.r2.transport.common.bridge.common.TransportResponseImpl;
 import com.linkedin.r2.transport.http.common.HttpBridge;
 
+import static com.linkedin.r2.transport.http.common.HttpBridge.NETTY_MAX_ACTIVE_STREAM_ERROR_MESSAGE;
+
+
 /**
  * @author Steven Ihde
  * @version $Revision: $
  */
 
 public class TestHttpBridge
 {
+  private static final int REGULAR_STREAM_ID = 2; // Can not be 0 or 1 as they are reserved in Netty
+
   @Test
   public void testRestToHttpErrorMessage() throws TimeoutException, InterruptedException
   {
@@ -144,4 +152,31 @@ public void testHttpToStreamErrorMessage() throws TimeoutException, InterruptedE
     // propagating the actual exception
     Assert.assertSame(resp, streamResponse);
   }
+
+  @Test
+  public void testStreamToHttpWithRetriableRequestException() throws TimeoutException, InterruptedException
+  {
+    URI uri = URI.create("http://some.host");
+
+    RestRequest r = new RestRequestBuilder(uri).build();
+
+    FutureCallback<StreamResponse> futureCallback = new FutureCallback<>();
+    TransportCallback<StreamResponse> callback = new TransportCallbackAdapter<>(futureCallback);
+    TransportCallback<StreamResponse> bridgeCallback = HttpBridge.streamToHttpCallback(callback,
+        Messages.toStreamRequest(r));
+
+    bridgeCallback.onResponse(TransportResponseImpl.<StreamResponse>error(
+        Http2Exception.streamError(REGULAR_STREAM_ID, Http2Error.REFUSED_STREAM,
+            NETTY_MAX_ACTIVE_STREAM_ERROR_MESSAGE + ": 200")));
+
+    try
+    {
+      futureCallback.get(30, TimeUnit.SECONDS);
+      Assert.fail("get should have thrown exception");
+    }
+    catch (ExecutionException e)
+    {
+      Assert.assertTrue(e.getCause() instanceof RetriableRequestException);
+    }
+  }
 }