GH-2939: Rely on custom AmqpHeaders.RETRY_COUNT for server retries

Fixes: #2939

The RabbitMQ 4.0 does not deal with client side `x-*` headers.
Therefore, an `x-death.count` is not incremented anymore when
message is re-published from client back to the broker.

* Spring AMQP 3.2 has introduced an `AmqpHeaders.RETRY_COUNT` custom header.
Use `messageProperties.incrementRetryCount()` in the `RabbitMessageChannelBinder`
when we re-published message back to the broker for server-side retries
* Fix docs respectively

Resolves #3019

Author: artembilan

binders/rabbit-binder/spring-cloud-stream-binder-rabbit/src/main/java/org/springframework/cloud/stream/binder/rabbit/RabbitMessageChannelBinder.java

@@ -815,6 +815,7 @@ private MessageProperties adjustMessagePropertiesHeader(Throwable cause, String
 						messageProperties.setDeliveryMode(
 								properties.getExtension().getRepublishDeliveyMode());
 					}
+					messageProperties.incrementRetryCount();
 					return messageProperties;
 				}
 

docs/modules/ROOT/pages/rabbit/rabbit_dlq.adoc

@@ -28,8 +28,6 @@ public class ReRouteDlqApplication {
 
     private static final String PARKING_LOT = ORIGINAL_QUEUE + ".parkingLot";
 
-    private static final String X_RETRIES_HEADER = "x-retries";
-
     public static void main(String[] args) throws Exception {
         ConfigurableApplicationContext context = SpringApplication.run(ReRouteDlqApplication.class, args);
         System.out.println("Press enter to exit");
@@ -42,12 +40,9 @@ public class ReRouteDlqApplication {
 
     @RabbitListener(queues = DLQ)
     public void rePublish(Message failedMessage) {
-        Integer retriesHeader = (Integer) failedMessage.getMessageProperties().getHeaders().get(X_RETRIES_HEADER);
-        if (retriesHeader == null) {
-            retriesHeader = Integer.valueOf(0);
-        }
-        if (retriesHeader < 3) {
-            failedMessage.getMessageProperties().getHeaders().put(X_RETRIES_HEADER, retriesHeader + 1);
+        long retries = failedMessage.getMessageProperties().getRetryCount();
+        if (retries < 3) {
+            failedMessage.getMessageProperties().incrementRetryCount();
             this.rabbitTemplate.send(ORIGINAL_QUEUE, failedMessage);
         }
         else {
@@ -74,8 +69,6 @@ public class ReRouteDlqApplication {
 
     private static final String PARKING_LOT = ORIGINAL_QUEUE + ".parkingLot";
 
-    private static final String X_RETRIES_HEADER = "x-retries";
-
     private static final String DELAY_EXCHANGE = "dlqReRouter";
 
     public static void main(String[] args) throws Exception {
@@ -90,13 +83,10 @@ public class ReRouteDlqApplication {
 
     @RabbitListener(queues = DLQ)
     public void rePublish(Message failedMessage) {
-        Map<String, Object> headers = failedMessage.getMessageProperties().getHeaders();
-        Integer retriesHeader = (Integer) headers.get(X_RETRIES_HEADER);
-        if (retriesHeader == null) {
-            retriesHeader = Integer.valueOf(0);
-        }
-        if (retriesHeader < 3) {
-            headers.put(X_RETRIES_HEADER, retriesHeader + 1);
+        long retries = failedMessage.getMessageProperties().getRetryCount();
+        if (retries < 3) {
+            failedMessage.getMessageProperties().incrementRetryCount();
+			Map<String, Object> headers = failedMessage.getMessageProperties().getHeaders();
             headers.put("x-delay", 5000 * retriesHeader);
             this.rabbitTemplate.send(DELAY_EXCHANGE, ORIGINAL_QUEUE, failedMessage);
         }
@@ -128,9 +118,10 @@ public class ReRouteDlqApplication {
 [[partitioned-destinations]]
 == Partitioned Destinations
 
-With partitioned destinations, there is one DLQ for all partitions. We determine the original queue from the headers.
+With partitioned destinations, there is one DLQ for all partitions.
+We determine the original queue from the headers.
 
-[[republishtodlq=false]]
+[[republishtodlq-false]]
 === `republishToDlq=false`
 
 When `republishToDlq` is `false`, RabbitMQ publishes the message to the DLX/DLQ with an `x-death` header containing information about the original destination, as shown in the following example:
@@ -148,8 +139,6 @@ public class ReRouteDlqApplication {
 
 	private static final String X_DEATH_HEADER = "x-death";
 
-	private static final String X_RETRIES_HEADER = "x-retries";
-
 	public static void main(String[] args) throws Exception {
 		ConfigurableApplicationContext context = SpringApplication.run(ReRouteDlqApplication.class, args);
 		System.out.println("Press enter to exit");
@@ -164,12 +153,9 @@ public class ReRouteDlqApplication {
 	@RabbitListener(queues = DLQ)
 	public void rePublish(Message failedMessage) {
 		Map<String, Object> headers = failedMessage.getMessageProperties().getHeaders();
-		Integer retriesHeader = (Integer) headers.get(X_RETRIES_HEADER);
-		if (retriesHeader == null) {
-			retriesHeader = Integer.valueOf(0);
-		}
-		if (retriesHeader < 3) {
-			headers.put(X_RETRIES_HEADER, retriesHeader + 1);
+		long retries = failedMessage.getMessageProperties().getRetryCount();
+		if (retries < 3) {
+			failedMessage.getMessageProperties().incrementRetryCount();
 			List<Map<String, ?>> xDeath = (List<Map<String, ?>>) headers.get(X_DEATH_HEADER);
 			String exchange = (String) xDeath.get(0).get("exchange");
 			List<String> routingKeys = (List<String>) xDeath.get(0).get("routing-keys");
@@ -188,7 +174,7 @@ public class ReRouteDlqApplication {
 }
 ----
 
-[[republishtodlq=true]]
+[[republishtodlq-true]]
 === `republishToDlq=true`
 
 When `republishToDlq` is `true`, the republishing recoverer adds the original exchange and routing key to headers, as shown in the following example:
@@ -204,8 +190,6 @@ public class ReRouteDlqApplication {
 
 	private static final String PARKING_LOT = ORIGINAL_QUEUE + ".parkingLot";
 
-	private static final String X_RETRIES_HEADER = "x-retries";
-
 	private static final String X_ORIGINAL_EXCHANGE_HEADER = RepublishMessageRecoverer.X_ORIGINAL_EXCHANGE;
 
 	private static final String X_ORIGINAL_ROUTING_KEY_HEADER = RepublishMessageRecoverer.X_ORIGINAL_ROUTING_KEY;
@@ -223,12 +207,9 @@ public class ReRouteDlqApplication {
 	@RabbitListener(queues = DLQ)
 	public void rePublish(Message failedMessage) {
 		Map<String, Object> headers = failedMessage.getMessageProperties().getHeaders();
-		Integer retriesHeader = (Integer) headers.get(X_RETRIES_HEADER);
-		if (retriesHeader == null) {
-			retriesHeader = Integer.valueOf(0);
-		}
-		if (retriesHeader < 3) {
-			headers.put(X_RETRIES_HEADER, retriesHeader + 1);
+		long retries = failedMessage.getMessageProperties().getRetryCount();
+		if (retries < 3) {
+			failedMessage.getMessageProperties().incrementRetryCount();
 			String exchange = (String) headers.get(X_ORIGINAL_EXCHANGE_HEADER);
 			String originalRoutingKey = (String) headers.get(X_ORIGINAL_ROUTING_KEY_HEADER);
 			this.rabbitTemplate.send(exchange, originalRoutingKey, failedMessage);