INT-3781: Configure HTTP GW Timeout Status Code

JIRA: https://jira.spring.io/browse/INT-3781

- Add mechanisms to set status code on an inbound gateway timeout.
- Send a message to the error channel if configured.

Polishing - Add failedMessage to MTE

Fix Schema Docs; Timeout Detection on Error Flow

Add Zookeeper Leadership Logs

Fix typo in the `SmartLifecycleRoleController`

spring-integration-core/src/main/java/org/springframework/integration/gateway/MessagingGatewaySupport.java

@@ -16,6 +16,7 @@
 
 package org.springframework.integration.gateway;
 
+import org.springframework.integration.MessageTimeoutException;
 import org.springframework.integration.core.MessagingTemplate;
 import org.springframework.integration.endpoint.AbstractEndpoint;
 import org.springframework.integration.endpoint.EventDrivenConsumer;
@@ -50,6 +51,16 @@ public abstract class MessagingGatewaySupport extends AbstractEndpoint implement
 
 	private static final long DEFAULT_TIMEOUT = 1000L;
 
+	private final SimpleMessageConverter messageConverter = new SimpleMessageConverter();
+
+	private final MessagingTemplate messagingTemplate;
+
+	private final HistoryWritingMessagePostProcessor historyWritingPostProcessor =
+			new HistoryWritingMessagePostProcessor();
+
+	private final Object replyMessageCorrelatorMonitor = new Object();
+
+	private final boolean errorOnTimeout;
 
 	private volatile MessageChannel requestChannel;
 
@@ -68,26 +79,34 @@ public abstract class MessagingGatewaySupport extends AbstractEndpoint implement
 	@SuppressWarnings("rawtypes")
 	private volatile InboundMessageMapper requestMapper = new DefaultRequestMapper();
 
-	private final SimpleMessageConverter messageConverter = new SimpleMessageConverter();
-
-	private final MessagingTemplate messagingTemplate;
-
-	private final HistoryWritingMessagePostProcessor historyWritingPostProcessor =
-			new HistoryWritingMessagePostProcessor();
-
 	private volatile boolean initialized;
 
 	private volatile AbstractEndpoint replyMessageCorrelator;
 
-	private final Object replyMessageCorrelatorMonitor = new Object();
-
 
+	/**
+	 * Construct an instance that will return null if no reply is received.
+	 */
 	public MessagingGatewaySupport() {
+		this(false);
+	}
+
+	/**
+	 * If errorOnTimeout is true, construct an instance that will send an
+	 * {@link ErrorMessage} with a {@link MessageTimeoutException} payload to the error
+	 * channel if a reply is expected but none is received. If no error channel is
+	 * configured, the {@link MessageTimeoutException} will be thrown.
+	 *
+	 * @param errorOnTimeout true to create the error message.
+	 * @since 4.2
+	 */
+	public MessagingGatewaySupport(boolean errorOnTimeout) {
 		MessagingTemplate template = new MessagingTemplate();
 		template.setMessageConverter(this.messageConverter);
 		template.setSendTimeout(DEFAULT_TIMEOUT);
 		template.setReceiveTimeout(this.replyTimeout);
 		this.messagingTemplate = template;
+		this.errorOnTimeout = errorOnTimeout;
 	}
 
 
@@ -333,6 +352,14 @@ public abstract class MessagingGatewaySupport extends AbstractEndpoint implement
 					error = ((ErrorMessage) reply).getPayload();
 				}
 			}
+			if (reply == null && this.errorOnTimeout) {
+				if (object instanceof Message) {
+					error = new MessageTimeoutException((Message<?>) object, "No reply received within timeout");
+				}
+				else {
+					error = new MessageTimeoutException("No reply received within timeout");
+				}
+			}
 		}
 		catch (Exception e) {
 			if (logger.isDebugEnabled()) {
@@ -363,6 +390,15 @@ public abstract class MessagingGatewaySupport extends AbstractEndpoint implement
 				if (errorFlowReply != null && errorFlowReply.getPayload() instanceof Throwable) {
 					this.rethrow((Throwable) errorFlowReply.getPayload(), "error flow returned an Error Message");
 				}
+				if (errorFlowReply == null && this.errorOnTimeout) {
+					if (object instanceof Message) {
+						throw new MessageTimeoutException((Message<?>) object,
+								"No reply received from error channel within timeout");
+					}
+					else {
+						throw new MessageTimeoutException("No reply received from error channel within timeout");
+					}
+				}
 				return errorFlowReply;
 			}
 			else { // no errorChannel so we'll propagate

spring-integration-core/src/main/java/org/springframework/integration/support/SmartLifecycleRoleController.java

@@ -141,15 +141,23 @@ public class SmartLifecycleRoleController implements ApplicationListener<Abstrac
 				}
 
 			});
+			if (logger.isDebugEnabled()) {
+				logger.debug("Zookeeper leadership granted: Starting: " + lifecycles);
+			}
 			for (SmartLifecycle lifecycle : lifecycles) {
 				try {
 					lifecycle.start();
 				}
 				catch (Exception e) {
-					logger.error("Failed to start " + lifecycle + " in role " + role);
+					logger.error("Failed to start " + lifecycle + " in role " + role, e);
 				}
 			}
 		}
+		else {
+			if (logger.isDebugEnabled()) {
+				logger.debug("Zookeeper leadership granted: Nothing to do");
+			}
+		}
 	}
 
 	/**
@@ -172,15 +180,23 @@ public class SmartLifecycleRoleController implements ApplicationListener<Abstrac
 				}
 
 			});
+			if (logger.isDebugEnabled()) {
+				logger.debug("Zookeeper leadership revoked: Stopping: " + lifecycles);
+			}
 			for (SmartLifecycle lifecycle : lifecycles) {
 				try {
 					lifecycle.stop();
 				}
 				catch (Exception e) {
-					logger.error("Failed to stop " + lifecycle + " in role " + role);
+					logger.error("Failed to stop " + lifecycle + " in role " + role, e);
 				}
 			}
 		}
+		else {
+			if (logger.isDebugEnabled()) {
+				logger.debug("Zookeeper leadership revoked: Nothing to do");
+			}
+		}
 	}
 
 	private void addLazyLifecycles() {

spring-integration-http/src/main/java/org/springframework/integration/http/config/HttpInboundEndpointParser.java

@@ -195,6 +195,10 @@ public class HttpInboundEndpointParser extends AbstractSingleBeanDefinitionParse
 
 		BeanDefinition statusCodeExpressionDef =
 				IntegrationNamespaceUtils.createExpressionDefIfAttributeDefined("status-code-expression", element);
+		if (statusCodeExpressionDef == null) {
+			statusCodeExpressionDef = IntegrationNamespaceUtils
+					.createExpressionDefIfAttributeDefined("reply-timeout-status-code-expression", element);
+		}
 		if (statusCodeExpressionDef != null) {
 			builder.addPropertyValue("statusCodeExpression", statusCodeExpressionDef);
 		}

spring-integration-http/src/main/java/org/springframework/integration/http/inbound/HttpRequestHandlingEndpointSupport.java

@@ -50,6 +50,7 @@ import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConvert
 import org.springframework.http.converter.xml.SourceHttpMessageConverter;
 import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.http.server.ServletServerHttpResponse;
+import org.springframework.integration.MessageTimeoutException;
 import org.springframework.integration.context.OrderlyShutdownCapable;
 import org.springframework.integration.expression.ExpressionUtils;
 import org.springframework.integration.gateway.MessagingGatewaySupport;
@@ -122,6 +123,8 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 
 	private final List<HttpMessageConverter<?>> defaultMessageConverters = new ArrayList<HttpMessageConverter<?>>();
 
+	private final boolean expectReply;
+
 	private volatile List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
 
 	private volatile RequestMapping requestMapping = new RequestMapping();
@@ -136,8 +139,6 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 
 	private volatile HeaderMapper<HttpHeaders> headerMapper = DefaultHttpHeaderMapper.inboundMapper();
 
-	private final boolean expectReply;
-
 	private volatile boolean extractReplyPayload = true;
 
 	private volatile MultipartResolver multipartResolver;
@@ -159,6 +160,7 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 	}
 
 	public HttpRequestHandlingEndpointSupport(boolean expectReply) {
+		super(expectReply);
 		this.expectReply = expectReply;
 		this.defaultMessageConverters.add(new MultipartAwareFormHttpMessageConverter());
 		this.defaultMessageConverters.add(new ByteArrayHttpMessageConverter());
@@ -331,7 +333,8 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 	/**
 	 * Specify the {@link Expression} to resolve a status code for Response
 	 * to override the default '200 OK'.
-	 * <p> The {@link #statusCodeExpression} is applied only for the one-way {@code <http:inbound-channel-adapter/>}.
+	 * <p> The {@link #statusCodeExpression} is applied only for the one-way {@code <http:inbound-channel-adapter/>}
+	 * or when no reply (timeout) is received for a gateway.
 	 * The {@code <http:inbound-gateway/>} resolves an {@link HttpStatus} from the
 	 * {@link org.springframework.integration.http.HttpHeaders#STATUS_CODE} reply {@link Message} header.
 	 * @param statusCodeExpression The status code Expression.
@@ -378,11 +381,6 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 		}
 		this.validateSupportedMethods();
 
-		if (this.expectReply && this.statusCodeExpression != null) {
-			logger.warn("The 'statusCodeExpression' is ignored when " +
-					"this component is configured as request/reply gateway");
-		}
-
 		if (this.statusCodeExpression != null) {
 			this.evaluationContext = createEvaluationContext();
 		}
@@ -505,7 +503,23 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 
 			Message<?> reply = null;
 			if (this.expectReply) {
-				reply = this.sendAndReceiveMessage(message);
+				try {
+					reply = this.sendAndReceiveMessage(message);
+				}
+				catch (MessageTimeoutException e) {
+					if (this.statusCodeExpression != null) {
+						reply = getMessageBuilderFactory().withPayload(e.getMessage())
+									.setHeader(org.springframework.integration.http.HttpHeaders.STATUS_CODE,
+											evaluateHttpStatus())
+									.build();
+					}
+					else {
+						reply = getMessageBuilderFactory().withPayload(e.getMessage())
+								.setHeader(org.springframework.integration.http.HttpHeaders.STATUS_CODE,
+										HttpStatus.INTERNAL_SERVER_ERROR)
+								.build();
+					}
+				}
 			}
 			else {
 				this.send(message);
@@ -552,17 +566,22 @@ public abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewa
 
 	protected void setStatusCodeIfNeeded(ServletServerHttpResponse response) {
 		if (this.statusCodeExpression != null) {
-			if (this.evaluationContext == null) {
-				this.evaluationContext = createEvaluationContext();
-			}
-			Object value = this.statusCodeExpression.getValue(this.evaluationContext);
-			HttpStatus httpStatus = buildHttpStatus(value);
+			HttpStatus httpStatus = evaluateHttpStatus();
 			if (httpStatus != null) {
 				response.setStatusCode(httpStatus);
 			}
 		}
 	}
 
+	private HttpStatus evaluateHttpStatus() {
+		if (this.evaluationContext == null) {
+			this.evaluationContext = createEvaluationContext();
+		}
+		Object value = this.statusCodeExpression.getValue(this.evaluationContext);
+		HttpStatus httpStatus = buildHttpStatus(value);
+		return httpStatus;
+	}
+
 	/**
 	 * Prepares an instance of {@link ServletServerHttpRequest} from the raw
 	 * {@link HttpServletRequest}. Also converts the request into a multipart request to

spring-integration-http/src/main/resources/org/springframework/integration/http/config/spring-integration-http-4.2.xsd

@@ -63,12 +63,12 @@
 				<xsd:annotation>
 					<xsd:documentation>
 						A SpEL expression that resolves to an 'HttpStatus' code when rendering a response.
-						The expression must return the object which can be converted to a
+						The expression must return an object which can be converted to a
 						'org.springframework.http.HttpStatus' enum value.
 						The 'evaluationContext' has a 'BeanResolver' but no variables, so the usage of this attribute
 						is somewhat limited.
 						An example might be to resolve, at runtime, some scoped Bean that returns an
-						'HttpStatus' value.
+						'HttpStatus' value, or use a literal expression e.g. "201".
 						By default 'status-code-expression' is null, meaning that the default '200 OK' response status
 						will be returned.
 						The 'http:inbound-gateway' resolves the 'status code' from the 'http_statusCode' header of the reply
@@ -203,6 +203,25 @@
 							]]></xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
+					<xsd:attribute name="reply-timeout-status-code-expression" type="xsd:string">
+						<xsd:annotation>
+							<xsd:documentation>
+								A SpEL expression that resolves to an 'HttpStatus' code when rendering a response after
+								a 'reply-timeout'.
+								The expression must return an object which can be converted to a
+								'org.springframework.http.HttpStatus' enum value.
+								The 'evaluationContext' has a 'BeanResolver' but no variables, so the usage of this attribute
+								is somewhat limited.
+								An example might be to resolve, at runtime, some scoped Bean that returns an
+								'HttpStatus' value, or use a literal expression e.g. "504".
+								By default 'status-code-expression' is null, meaning that the default
+								'500 Internal Server Error' response status will be returned after a timeout.
+								When a timeout is not encountered,
+								the 'http:inbound-gateway' resolves the 'status code' from the 'http_statusCode' header of the reply
+								Message.
+							</xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
 				</xsd:extension>
 			</xsd:complexContent>
 		</xsd:complexType>

spring-integration-http/src/test/java/org/springframework/integration/http/inbound/HttpRequestHandlingMessagingGatewayTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.integration.http.inbound;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.mock;
 
 import java.io.IOException;
@@ -26,27 +27,32 @@ import java.io.PrintWriter;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
+import org.hamcrest.Matchers;
 import org.junit.Test;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.expression.common.LiteralExpression;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.AbstractHttpMessageConverter;
 import org.springframework.http.converter.ByteArrayHttpMessageConverter;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.http.converter.HttpMessageNotWritableException;
-import org.springframework.messaging.Message;
 import org.springframework.integration.channel.DirectChannel;
 import org.springframework.integration.channel.QueueChannel;
 import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
 import org.springframework.integration.http.AbstractHttpInboundTests;
+import org.springframework.integration.http.HttpHeaders;
 import org.springframework.integration.http.converter.SerializingHttpMessageConverter;
 import org.springframework.integration.support.MessageBuilder;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.GenericMessage;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.util.LinkedMultiValueMap;
@@ -296,6 +302,92 @@ public class HttpRequestHandlingMessagingGatewayTests extends AbstractHttpInboun
 		assertEquals("text/plain", contentTypes.get(0));
 	}
 
+	@Test
+	public void timeoutDefault() throws Exception {
+		QueueChannel requestChannel = new QueueChannel();
+		HttpRequestHandlingMessagingGateway gateway = new HttpRequestHandlingMessagingGateway(true);
+		gateway.setBeanFactory(mock(BeanFactory.class));
+		gateway.setRequestChannel(requestChannel);
+		gateway.setReplyTimeout(0);
+		gateway.afterPropertiesSet();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("GET");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		gateway.handleRequest(request, response);
+		Message<?> message = requestChannel.receive(0);
+		assertNotNull(message);
+		assertEquals(500, response.getStatus());
+	}
+
+	@Test
+	public void timeoutStatusExpression() throws Exception {
+		QueueChannel requestChannel = new QueueChannel();
+		HttpRequestHandlingMessagingGateway gateway = new HttpRequestHandlingMessagingGateway(true);
+		gateway.setBeanFactory(mock(BeanFactory.class));
+		gateway.setRequestChannel(requestChannel);
+		gateway.setReplyTimeout(0);
+		gateway.setStatusCodeExpression(new LiteralExpression("501"));
+		gateway.afterPropertiesSet();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("GET");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		gateway.handleRequest(request, response);
+		Message<?> message = requestChannel.receive(0);
+		assertNotNull(message);
+		assertEquals(501, response.getStatus());
+	}
+
+	@Test
+	public void timeoutErrorFlow() throws Exception {
+		QueueChannel requestChannel = new QueueChannel();
+		HttpRequestHandlingMessagingGateway gateway = new HttpRequestHandlingMessagingGateway(true);
+		gateway.setBeanFactory(mock(BeanFactory.class));
+		gateway.setRequestChannel(requestChannel);
+		gateway.setReplyTimeout(0);
+		DirectChannel errorChannel = new DirectChannel();
+		errorChannel.subscribe(new AbstractReplyProducingMessageHandler() {
+
+			@Override
+			protected Object handleRequestMessage(Message<?> requestMessage) {
+				return new GenericMessage<String>("foo",
+						Collections.<String, Object> singletonMap(HttpHeaders.STATUS_CODE, HttpStatus.GATEWAY_TIMEOUT));
+			}
+
+		});
+		gateway.setErrorChannel(errorChannel);
+		gateway.afterPropertiesSet();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("GET");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		gateway.handleRequest(request, response);
+		Message<?> message = requestChannel.receive(0);
+		assertNotNull(message);
+		assertEquals(504, response.getStatus());
+	}
+
+	@Test
+	public void timeoutErrorFlowTimeout() throws Exception {
+		QueueChannel requestChannel = new QueueChannel();
+		HttpRequestHandlingMessagingGateway gateway = new HttpRequestHandlingMessagingGateway(true);
+		gateway.setBeanFactory(mock(BeanFactory.class));
+		gateway.setRequestChannel(requestChannel);
+		gateway.setReplyTimeout(0);
+		QueueChannel errorChannel = new QueueChannel();
+		gateway.setErrorChannel(errorChannel);
+		gateway.setStatusCodeExpression(new LiteralExpression("501"));
+		gateway.afterPropertiesSet();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("GET");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		gateway.handleRequest(request, response);
+		Message<?> message = requestChannel.receive(0);
+		assertNotNull(message);
+		assertEquals(501, response.getStatus());
+		assertThat(response.getContentAsString(), Matchers.containsString("from error channel"));
+	}
+
+
+
 	private class ContentTypeCheckingMockHttpServletResponse extends MockHttpServletResponse {
 
 		private final List<String> contentTypeList = new ArrayList<String>();

spring-integration-zookeeper/src/test/resources/log4j.properties

@@ -6,3 +6,4 @@ log4j.appender.stdout.layout.ConversionPattern=%d{HH:mm:ss.SSS} %-5p [%t][%c] %m
 
 log4j.category.org.springframework.integration=WARN
 log4j.category.org.springframework.integration.zookeeper=INFO
+log4j.category.org.springframework.integration.support.SmartLifecycleRoleController=DEBUG

src/reference/asciidoc/http.adoc

@@ -267,7 +267,7 @@ This allows you to get the `Message` into the flow as early as possibly, e.g.:
 
 For more information regarding _Handler Mappings_, please see: http://static.springsource.org/spring/docs/current/spring-framework-reference/html/mvc.html#mvc-handlermapping[Handler Mappings].
 
-[[cors]]
+[[http-cors]]
 ==== Cross-Origin Resource Sharing (CORS) Support
 
 Starting with _version 4.2_ the `<http:inbound-channel-adapter>` and `<http:inbound-gateway>` can be configured with
@@ -308,12 +308,13 @@ Default value is 1800 seconds, or 30 minutes.
 The CORS Java Configuration is represented by the `org.springframework.integration.http.inbound.CrossOrigin` class,
 instances of which can be injected to the `HttpRequestHandlingEndpointSupport` beans.
 
+[[http-response-statuscode]]
 ==== Response StatusCode
 
 Starting with _version 4.1_ the `<http:inbound-channel-adapter>` can be configured with a `status-code-expression` to override the default `200 OK` status.
 The expression must return an object which can be converted to an `org.springframework.http.HttpStatus` enum value.
 The `evaluationContext` has a `BeanResolver` but no variables, so the usage of this attribute is somewhat limited.
-An example might be to resolve, at runtime, some scoped Bean that returns a status code value but, most likely, it will be set to a fixed value such as `status-code=expression="'204'"` (No Content), or `status-code-expression="T(org.springframework.http.HttpStatus).NO_CONTENT"`.
+An example might be to resolve, at runtime, some scoped Bean that returns a status code value but, most likely, it will be set to a fixed value such as `status-code=expression="204"` (No Content), or `status-code-expression="T(org.springframework.http.HttpStatus).NO_CONTENT"`.
 By default, `status-code-expression` is null meaning that the normal '200 OK' response status will be returned.
 [source,xml]
 ----
@@ -325,6 +326,33 @@ By default, `status-code-expression` is null meaning that the normal '200 OK' re
 ----
 
 The `<http:inbound-gateway>` resolves the 'status code' from the `http_statusCode` header of the reply Message.
+Starting with _version 4.2_, the default response status code when no reply is received within the `reply-timeout`
+is `500 Internal Server Error`.
+There are two ways to modify this behavior:
+
+- add a `reply-timeout-status-code-expression` - this has the same semantics as the `status-code-expression` on the
+inbound adapter.
+- Add an `error-channel` and return an appropriate message with an http status code header, such as...
+
+[source, xml]
+----
+<int:chain input-channel="errors">
+    <int:header-enricher>
+        <int:header name="http_statusCode" value="504" />
+    </int:header-enricher>
+    <int:transformer expression="payload.message" />
+</int:chain>
+----
+
+The payload of the `ErrorMessage` is a `MessageTimeoutException`; it must be transformed to something that can be
+converted by the gateway, such as a `String`; a good candidate is the exception's message property, which is the
+value used when using the expression technique.
+
+If the error flow times out after a main flow timeout, `500 Internal Server Error` is returned, or the
+`reply-timeout-status-code-expression` is evaluated, if present.
+
+NOTE: previously, the default status code for a timeout was `200 OK`; to restore that behavior, set
+`reply-timeout-status-code-expression="200"`.
 
 ==== URI Template Variables and Expressions
 

src/reference/asciidoc/whats-new.adoc

@@ -202,10 +202,19 @@ See <<xml-xpath-splitting>> for more information.
 [[x4.2-http-changes]]
 ==== HTTP Changes
 
+===== CORS
+
 The HTTP Inbound Endpoints (`<int-http:inbound-channel-adapter>` and `<int-http:inbound-gateway>`) now allow the
 configuration of _Cross-Origin Resource Sharing (CORS)_.
 
-See <<cors>> for more information.
+See <<http-cors>> for more information.
+
+===== Inbound Gateway Timeout
+
+The HTTP inbound gateway can be configured as to what status code to return when a request times out.
+The default is now `500 Internal Server Error` instead of `200 OK`.
+
+See <<http-response-statuscode>> for more information.
 
 [[x4.2-file-filter]]
 ==== Persistent File List Filter Changes