Add documentation for ServiceBus Binder retry configuration

- Updated CHANGELOG.md for both ServiceBus binder and integration modules
- Created comprehensive RETRY_CONFIGURATION.md guide
- Documented configuration properties, behavior, examples, and best practices

Co-authored-by: saragluna <31124698+saragluna@users.noreply.github.com>

Author: Copilot

sdk/spring/spring-cloud-azure-stream-binder-servicebus/CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Features Added
 
+- Added support for Spring Cloud Stream's consumer retry properties (`maxAttempts`, `backOffInitialInterval`, `backOffMaxInterval`, `backOffMultiplier`) to enable automatic retry with exponential backoff for message processing failures.
+
 ### Breaking Changes
 
 ### Bugs Fixed

sdk/spring/spring-cloud-azure-stream-binder-servicebus/RETRY_CONFIGURATION.md

@@ -0,0 +1,163 @@
+# ServiceBus Binder Retry Configuration
+
+## Overview
+
+The ServiceBus Binder now supports Spring Cloud Stream's consumer retry properties, enabling automatic retry with exponential backoff for message processing failures.
+
+## Configuration
+
+You can configure retry behavior using the following properties in your `application.yml` or `application.properties`:
+
+### YAML Configuration Example
+
+```yaml
+spring:
+  cloud:
+    stream:
+      bindings:
+        consumer-in-0:
+          destination: my-queue
+          group: my-group
+          consumer:
+            max-attempts: 5                    # Maximum number of retry attempts (default: 3)
+            back-off-initial-interval: 1000    # Initial backoff interval in milliseconds (default: 1000)
+            back-off-max-interval: 10000       # Maximum backoff interval in milliseconds (default: 10000)
+            back-off-multiplier: 2.0           # Backoff multiplier (default: 2.0)
+      binders:
+        servicebus:
+          type: servicebus
+```
+
+### Properties Configuration Example
+
+```properties
+spring.cloud.stream.bindings.consumer-in-0.destination=my-queue
+spring.cloud.stream.bindings.consumer-in-0.group=my-group
+spring.cloud.stream.bindings.consumer-in-0.consumer.max-attempts=5
+spring.cloud.stream.bindings.consumer-in-0.consumer.back-off-initial-interval=1000
+spring.cloud.stream.bindings.consumer-in-0.consumer.back-off-max-interval=10000
+spring.cloud.stream.bindings.consumer-in-0.consumer.back-off-multiplier=2.0
+```
+
+## How It Works
+
+### Retry Behavior
+
+When a message processing fails (throws an exception), the binder will:
+
+1. **Retry Automatically**: Retry processing the message based on the `max-attempts` setting
+2. **Exponential Backoff**: Wait between retries using an exponential backoff strategy:
+   - First retry: waits `back-off-initial-interval` milliseconds
+   - Subsequent retries: wait time is multiplied by `back-off-multiplier`
+   - Maximum wait: capped at `back-off-max-interval` milliseconds
+
+### Example Retry Timeline
+
+With the configuration above (`max-attempts: 5`, `back-off-initial-interval: 1000`, `back-off-multiplier: 2.0`, `back-off-max-interval: 10000`):
+
+- **Attempt 1**: Initial processing (fails)
+- **Wait**: 1000ms (1 second)
+- **Attempt 2**: Retry 1 (fails)
+- **Wait**: 2000ms (2 seconds) = 1000ms × 2.0
+- **Attempt 3**: Retry 2 (fails)
+- **Wait**: 4000ms (4 seconds) = 2000ms × 2.0
+- **Attempt 4**: Retry 3 (fails)
+- **Wait**: 8000ms (8 seconds) = 4000ms × 2.0
+- **Attempt 5**: Retry 4 (final attempt, fails)
+- **Result**: Message is sent to error channel or dead letter queue (if configured)
+
+### After All Retries Exhausted
+
+When all retry attempts are exhausted:
+
+- If `requeue-rejected: false` (default), the message is **abandoned**
+- If `requeue-rejected: true`, the message is sent to the **dead letter queue**
+
+## Consumer Example
+
+```java
+@Bean
+public Consumer<Message<String>> consumer() {
+    return message -> {
+        // This method will be automatically retried if it throws an exception
+        processMessage(message.getPayload());
+    };
+}
+
+private void processMessage(String payload) {
+    // Your business logic here
+    // If this throws an exception, the message will be retried
+    if (shouldFail(payload)) {
+        throw new RuntimeException("Processing failed");
+    }
+    // Successfully processed
+}
+```
+
+## Dead Letter Queue Configuration
+
+To send failed messages to the dead letter queue after all retries are exhausted:
+
+```yaml
+spring:
+  cloud:
+    stream:
+      servicebus:
+        bindings:
+          consumer-in-0:
+            consumer:
+              requeue-rejected: true  # Send failed messages to DLQ
+```
+
+## Disabling Retry
+
+To disable retry (process message only once), set `max-attempts` to 1:
+
+```yaml
+spring:
+  cloud:
+    stream:
+      bindings:
+        consumer-in-0:
+          consumer:
+            max-attempts: 1  # No retries
+```
+
+## Best Practices
+
+1. **Choose Appropriate Max Attempts**: Consider the nature of your failures. Transient network issues might benefit from more retries, while business logic errors might not.
+
+2. **Configure Realistic Backoff Intervals**: Ensure your backoff intervals are appropriate for your use case:
+   - Too short: May overwhelm downstream services
+   - Too long: May delay message processing unnecessarily
+
+3. **Monitor Dead Letter Queues**: Set up monitoring and alerting for messages in the DLQ to handle persistent failures.
+
+4. **Use Specific Exception Types**: Consider catching specific exceptions in your consumer and only retrying for transient errors.
+
+5. **Test Your Configuration**: Use integration tests to verify your retry configuration works as expected.
+
+## Troubleshooting
+
+### Retries Not Working
+
+- Verify `max-attempts` is greater than 1
+- Check that exceptions are being thrown from your consumer
+- Enable debug logging: `logging.level.org.springframework.retry=DEBUG`
+
+### Too Many Retries
+
+- Reduce `max-attempts`
+- Increase `back-off-initial-interval` or reduce `back-off-multiplier`
+- Consider implementing circuit breaker patterns for persistent failures
+
+### Messages Going to DLQ Immediately
+
+- Verify `requeue-rejected` is set correctly
+- Check if `max-attempts` is set to 1
+- Review error handling logic in your consumer
+
+## Related Configuration
+
+- [Spring Cloud Stream Binding Properties](https://docs.spring.io/spring-cloud-stream/docs/current/reference/html/spring-cloud-stream.html#_consumer_properties)
+- [Azure Service Bus Error Handling](https://learn.microsoft.com/azure/service-bus-messaging/service-bus-dead-letter-queues)

sdk/spring/spring-integration-azure-servicebus/CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Features Added
 
+- Added `setRetryTemplate` method to `ServiceBusInboundChannelAdapter` to support configurable retry logic for message processing.
+
 ### Breaking Changes
 
 ### Bugs Fixed