+
+
+Usage
+To use the RabbitMQ binder, you can add it to your Spring Cloud Stream application, by using the following Maven coordinates:
+<dependency>
+ <groupId>org.springframework.cloud</groupId>
+ <artifactId>spring-cloud-stream-binder-rabbit</artifactId>
+</dependency>Alternatively, you can use the Spring Cloud Stream RabbitMQ Starter, as follows:
+<dependency>
+ <groupId>org.springframework.cloud</groupId>
+ <artifactId>spring-cloud-starter-stream-rabbit</artifactId>
+</dependency>RabbitMQ Binder Overview
+The following simplified diagram shows how the RabbitMQ binder operates:
+
+By default, the RabbitMQ Binder implementation maps each destination to a TopicExchange.
+For each consumer group, a Queue is bound to that TopicExchange.
+Each consumer instance has a corresponding RabbitMQ Consumer instance for its group’s Queue.
+For partitioned producers and consumers, the queues are suffixed with the partition index and use the partition index as the routing key.
+For anonymous consumers (those with no group property), an auto-delete queue (with a randomized unique name) is used.
By using the optional autoBindDlq option, you can configure the binder to create and configure dead-letter queues (DLQs) (and a dead-letter exchange DLX, as well as routing infrastructure).
+By default, the dead letter queue has the name of the destination, appended with .dlq.
+If retry is enabled (maxAttempts > 1), failed messages are delivered to the DLQ after retries are exhausted.
+If retry is disabled (maxAttempts = 1), you should set requeueRejected to false (the default) so that failed messages are routed to the DLQ, instead of being re-queued.
+In addition, republishToDlq causes the binder to publish a failed message to the DLQ (instead of rejecting it).
+This feature lets additional information (such as the stack trace in the x-exception-stacktrace header) be added to the message in headers.
+See the frameMaxHeadroom property for information about truncated stack traces.
+This option does not need retry enabled.
+You can republish a failed message after just one attempt.
+Starting with version 1.2, you can configure the delivery mode of republished messages.
+See the republishDeliveryMode property.
If the stream listener throws an ImmediateAcknowledgeAmqpException, the DLQ is bypassed and the message simply discarded.
+Starting with version 2.1, this is true regardless of the setting of republishToDlq; previously it was only the case when republishToDlq was false.
| + + | +
+Setting requeueRejected to true (with republishToDlq=false ) causes the message to be re-queued and redelivered continually, which is likely not what you want unless the reason for the failure is transient.
+In general, you should enable retry within the binder by setting maxAttempts to greater than one or by setting republishToDlq to true.
+ |
+
See RabbitMQ Binder Properties for more information about these properties.
+The framework does not provide any standard mechanism to consume dead-letter messages (or to re-route them back to the primary queue). +Some options are described in [rabbit-dlq-processing].
+| + + | +
+When multiple RabbitMQ binders are used in a Spring Cloud Stream application, it is important to disable 'RabbitAutoConfiguration' to avoid the same configuration from RabbitAutoConfiguration being applied to the two binders.
+You can exclude the class by using the @SpringBootApplication annotation.
+ |
+
Starting with version 2.0, the RabbitMessageChannelBinder sets the RabbitTemplate.userPublisherConnection property to true so that the non-transactional producers avoid deadlocks on consumers, which can happen if cached connections are blocked because of a memory alarm on the broker.
| + + | +
+Currently, a multiplex consumer (a single consumer listening to multiple queues) is only supported for message-driven conssumers; polled consumers can only retrieve messages from a single queue.
+ |
+
Configuration Options
+This section contains settings specific to the RabbitMQ Binder and bound channels.
+For general binding configuration options and properties, see the Spring Cloud Stream core documentation.
+RabbitMQ Binder Properties
+By default, the RabbitMQ binder uses Spring Boot’s ConnectionFactory.
+Conseuqently, it supports all Spring Boot configuration options for RabbitMQ.
+(For reference, see the Spring Boot documentation).
+RabbitMQ configuration options use the spring.rabbitmq prefix.
In addition to Spring Boot options, the RabbitMQ binder supports the following properties:
+-
+
- spring.cloud.stream.rabbit.binder.adminAddresses +
-
+
A comma-separated list of RabbitMQ management plugin URLs. +Only used when
+nodescontains more than one entry. +Each entry in this list must have a corresponding entry inspring.rabbitmq.addresses. +Only needed if you use a RabbitMQ cluster and wish to consume from the node that hosts the queue. +See Queue Affinity and the LocalizedQueueConnectionFactory for more information.++Default: empty.
+
+ - spring.cloud.stream.rabbit.binder.nodes +
-
+
A comma-separated list of RabbitMQ node names. +When more than one entry, used to locate the server address where a queue is located. +Each entry in this list must have a corresponding entry in
+spring.rabbitmq.addresses. +Only needed if you use a RabbitMQ cluster and wish to consume from the node that hosts the queue. +See Queue Affinity and the LocalizedQueueConnectionFactory for more information.++Default: empty.
+
+ - spring.cloud.stream.rabbit.binder.compressionLevel +
-
+
The compression level for compressed bindings. +See
+java.util.zip.Deflater.++Default:
+1(BEST_LEVEL).
+ - spring.cloud.stream.binder.connection-name-prefix +
-
+
A connection name prefix used to name the connection(s) created by this binder. +The name is this prefix followed by
+#n, wherenincrements each time a new connection is opened.++Default: none (Spring AMQP default).
+
+
RabbitMQ Consumer Properties
+The following properties are available for Rabbit consumers only and must be prefixed with spring.cloud.stream.rabbit.bindings.<channelName>.consumer..
However if the same set of properties needs to be applied to most bindings, to
+avoid repetition, Spring Cloud Stream supports setting values for all channels,
+in the format of spring.cloud.stream.rabbit.default.<property>=<value>.
Also, keep in mind that binding specific property will override its equivalent in the default.
+-
+
- acknowledgeMode +
-
+
The acknowledge mode.
+++Default:
+AUTO.
+ - anonymousGroupPrefix +
-
+
When the binding has no
+groupproperty, an anonymous, auto-delete queue is bound to the destination exchange. +The default naming stragegy for such queues results in a queue namedanonymous.<base64 representation of a UUID>. +Set this property to change the prefix to something other than the default.++Default:
+anonymous..
+ - autoBindDlq +
-
+
Whether to automatically declare the DLQ and bind it to the binder DLX.
+++Default:
+false.
+ - bindingRoutingKey +
-
+
The routing key with which to bind the queue to the exchange (if
+bindQueueistrue). +Can be multiple keys - seebindingRoutingKeyDelimiter. +For partitioned destinations,-<instanceIndex>is appended to each key.++Default:
+#.
+ - bindingRoutingKeyDelimiter +
-
+
When this is not null, 'bindingRoutingKey' is considered to be a list of keys delimited by this value; often a comma is used.
+++Default:
+null.
+ - bindQueue +
-
+
Whether to declare the queue and bind it to the destination exchange. +Set it to
+falseif you have set up your own infrastructure and have previously created and bound the queue.++Default:
+true.
+ - consumerTagPrefix +
-
+
Used to create the consumer tag(s); will be appended by
+#nwherenincrements for each consumer created. +Example:${spring.application.name}-${spring.cloud.stream.bindings.input.group}-${spring.cloud.stream.instance-index}.++Default: none - the broker will generate random consumer tags.
+
+ - containerType +
-
+
Select the type of listener container to be used. +See Choosing a Container in the Spring AMQP documentation for more information.
+++Default:
+simple
+ - deadLetterQueueName +
-
+
The name of the DLQ
+++Default:
+prefix+destination.dlq
+ - deadLetterExchange +
-
+
A DLX to assign to the queue. +Relevant only if
+autoBindDlqistrue.++Default: 'prefix+DLX'
+
+ - deadLetterExchangeType +
-
+
The type of the DLX to assign to the queue. +Relevant only if
+autoBindDlqistrue.++Default: 'direct'
+
+ - deadLetterRoutingKey +
-
+
A dead letter routing key to assign to the queue. +Relevant only if
+autoBindDlqistrue.++Default:
+destination
+ - declareDlx +
-
+
Whether to declare the dead letter exchange for the destination. +Relevant only if
+autoBindDlqistrue. +Set tofalseif you have a pre-configured DLX.++Default:
+true.
+ - declareExchange +
-
+
Whether to declare the exchange for the destination.
+++Default:
+true.
+ - delayedExchange +
-
+
Whether to declare the exchange as a
+Delayed Message Exchange. +Requires the delayed message exchange plugin on the broker. +Thex-delayed-typeargument is set to theexchangeType.++Default:
+false.
+ - dlqBindingArguments +
-
+
Arguments applied when binding the dlq to the dead letter exchange; used with
+headersdeadLetterExchangeTypeto specify headers to match on. +For example…dlqBindingArguments.x-match=any,…dlqBindingArguments.someHeader=someValue.++Default: empty
+
+ - dlqDeadLetterExchange +
-
+
If a DLQ is declared, a DLX to assign to that queue.
+++Default:
+none
+ - dlqDeadLetterRoutingKey +
-
+
If a DLQ is declared, a dead letter routing key to assign to that queue.
+++Default:
+none
+ - dlqExpires +
-
+
How long before an unused dead letter queue is deleted (in milliseconds).
+++Default:
+no expiration
+ - dlqLazy +
-
+
Declare the dead letter queue with the
+x-queue-mode=lazyargument. +See “Lazy Queues”. +Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue.++Default:
+false.
+ - dlqMaxLength +
-
+
Maximum number of messages in the dead letter queue.
+++Default:
+no limit
+ - dlqMaxLengthBytes +
-
+
Maximum number of total bytes in the dead letter queue from all messages.
+++Default:
+no limit
+ - dlqMaxPriority +
-
+
Maximum priority of messages in the dead letter queue (0-255).
+++Default:
+none
+ - dlqOverflowBehavior +
-
+
Action to take when
+dlqMaxLengthordlqMaxLengthBytesis exceeded; currentlydrop-headorreject-publishbut refer to the RabbitMQ documentation.++Default:
+none
+ - dlqQuorum.deliveryLimit +
-
+
When
+quorum.enabled=true, set a delivery limit after which the message is dropped or dead-lettered.++Default: none - broker default will apply.
+
+ - dlqQuorum.enabled +
-
+
When true, create a quorum dead letter queue instead of a classic queue.
+++Default: false
+
+ - dlqQuorum.initialQuorumSize +
-
+
When
+quorum.enabled=true, set the initial quorum size.++Default: none - broker default will apply.
+
+ - dlqSingleActiveConsumer +
-
+
Set to true to set the
+x-single-active-consumerqueue property to true.++Default:
+false
+ - dlqTtl +
-
+
Default time to live to apply to the dead letter queue when declared (in milliseconds).
+++Default:
+no limit
+ - durableSubscription +
-
+
Whether the subscription should be durable. +Only effective if
+groupis also set.++Default:
+true.
+ - exchangeAutoDelete +
-
+
If
+declareExchangeis true, whether the exchange should be auto-deleted (that is, removed after the last queue is removed).++Default:
+true.
+ - exchangeDurable +
-
+
If
+declareExchangeis true, whether the exchange should be durable (that is, it survives broker restart).++Default:
+true.
+ - exchangeType +
-
+
The exchange type:
+direct,fanout,headersortopicfor non-partitioned destinations anddirect, headers ortopicfor partitioned destinations.++Default:
+topic.
+ - exclusive +
-
+
Whether to create an exclusive consumer. +Concurrency should be 1 when this is
+true. +Often used when strict ordering is required but enabling a hot standby instance to take over after a failure. +SeerecoveryInterval, which controls how often a standby instance attempts to consume. +Consider usingsingleActiveConsumerinstead when using RabbitMQ 3.8 or later.++Default:
+false.
+ - expires +
-
+
How long before an unused queue is deleted (in milliseconds).
+++Default:
+no expiration
+ - failedDeclarationRetryInterval +
-
+
The interval (in milliseconds) between attempts to consume from a queue if it is missing.
+++Default: 5000
+
+
-
+
- frameMaxHeadroom +
-
+
The number of bytes to reserve for other headers when adding the stack trace to a DLQ message header. +All headers must fit within the
+frame_maxsize configured on the broker. +Stack traces can be large; if the size plus this property exceedsframe_maxthen the stack trace will be truncated. +A WARN log will be written; consider increasing theframe_maxor reducing the stack trace by catching the exception and throwing one with a smaller stack trace.++Default: 20000
+
+ - headerPatterns +
-
+
Patterns for headers to be mapped from inbound messages.
+++Default:
+['*'](all headers).
+ - lazy +
-
+
Declare the queue with the
+x-queue-mode=lazyargument. +See “Lazy Queues”. +Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue.++Default:
+false.
+ - maxConcurrency +
-
+
The maximum number of consumers. +Not supported when the
+containerTypeisdirect.++Default:
+1.
+ - maxLength +
-
+
The maximum number of messages in the queue.
+++Default:
+no limit
+ - maxLengthBytes +
-
+
The maximum number of total bytes in the queue from all messages.
+++Default:
+no limit
+ - maxPriority +
-
+
The maximum priority of messages in the queue (0-255).
+++Default:
+none
+ - missingQueuesFatal +
-
+
When the queue cannot be found, whether to treat the condition as fatal and stop the listener container. +Defaults to
+falseso that the container keeps trying to consume from the queue — for example, when using a cluster and the node hosting a non-HA queue is down.++Default:
+false
+ - overflowBehavior +
-
+
Action to take when
+maxLengthormaxLengthBytesis exceeded; currentlydrop-headorreject-publishbut refer to the RabbitMQ documentation.++Default:
+none
+ - prefetch +
-
+
Prefetch count.
+++Default:
+1.
+ - prefix +
-
+
A prefix to be added to the name of the
+destinationand queues.++Default: "".
+
+ - queueBindingArguments +
-
+
Arguments applied when binding the queue to the exchange; used with
+headersexchangeTypeto specify headers to match on. +For example…queueBindingArguments.x-match=any,…queueBindingArguments.someHeader=someValue.++Default: empty
+
+ - queueDeclarationRetries +
-
+
The number of times to retry consuming from a queue if it is missing. +Relevant only when
+missingQueuesFatalistrue. +Otherwise, the container keeps retrying indefinitely. +Not supported when thecontainerTypeisdirect.++Default:
+3
+ - queueNameGroupOnly +
-
+
When true, consume from a queue with a name equal to the
+group. +Otherwise the queue name isdestination.group. +This is useful, for example, when using Spring Cloud Stream to consume from an existing RabbitMQ queue.++Default: false.
+
+ - quorum.deliveryLimit +
-
+
When
+quorum.enabled=true, set a delivery limit after which the message is dropped or dead-lettered.++Default: none - broker default will apply.
+
+ - quorum.enabled +
-
+
When true, create a quorum queue instead of a classic queue.
+++Default: false
+
+ - quorum.initialQuorumSize +
-
+
When
+quorum.enabled=true, set the initial quorum size.++Default: none - broker default will apply.
+
+ - recoveryInterval +
-
+
The interval between connection recovery attempts, in milliseconds.
+++Default:
+5000.
+ - requeueRejected +
-
+
Whether delivery failures should be re-queued when retry is disabled or
+republishToDlqisfalse.++Default:
+false.
+
-
+
- republishDeliveryMode +
-
+
When
+republishToDlqistrue, specifies the delivery mode of the republished message.++Default:
+DeliveryMode.PERSISTENT
+ - republishToDlq +
-
+
By default, messages that fail after retries are exhausted are rejected. +If a dead-letter queue (DLQ) is configured, RabbitMQ routes the failed message (unchanged) to the DLQ. +If set to
+true, the binder republishs failed messages to the DLQ with additional headers, including the exception message and stack trace from the cause of the final failure. +Also see the frameMaxHeadroom property.++Default: false
+
+ - singleActiveConsumer +
-
+
Set to true to set the
+x-single-active-consumerqueue property to true.++Default:
+false
+ - transacted +
-
+
Whether to use transacted channels.
+++Default:
+false.
+ - ttl +
-
+
Default time to live to apply to the queue when declared (in milliseconds).
+++Default:
+no limit
+ - txSize +
-
+
The number of deliveries between acks. +Not supported when the
+containerTypeisdirect.++Default:
+1.
+
Advanced Listener Container Configuration
+To set listener container properties that are not exposed as binder or binding properties, add a single bean of type ListenerContainerCustomizer to the application context.
+The binder and binding properties will be set and then the customizer will be called.
+The customizer (configure() method) is provided with the queue name as well as the consumer group as arguments.
Advanced Queue/Exchange/Binding Configuration
+From time to time, the RabbitMQ team add new features that are enabled by setting some argument when declaring, for example, a queue.
+Generally, such features are enabled in the binder by adding appropriate properties, but this may not be immediately available in a current version.
+Starting with version 3.0.1, you can now add DeclarableCustomizer bean(s) to the application context to modify a Declarable (Queue, Exchange or Binding) just before the declaration is performed.
+This allows you to add arguments that are not currently directly supported by the binder.
Receiving Batched Messages
+Normally, if a producer binding has batch-enabled=true (see Rabbit Producer Properties), or a message is created by a BatchingRabbitTemplate, elements of the batch are returned as individual calls to the listener method.
+Starting with version 3.0, any such batch can be presented as a List<?> to the listener method if spring.cloud.stream.bindings.<name>.consumer.batch-mode is set to true.
Rabbit Producer Properties
+The following properties are available for Rabbit producers only and must be prefixed with spring.cloud.stream.rabbit.bindings.<channelName>.producer..
However if the same set of properties needs to be applied to most bindings, to
+avoid repetition, Spring Cloud Stream supports setting values for all channels,
+in the format of spring.cloud.stream.rabbit.default.<property>=<value>.
Also, keep in mind that binding specific property will override its equivalent in the default.
+-
+
- autoBindDlq +
-
+
Whether to automatically declare the DLQ and bind it to the binder DLX.
+++Default:
+false.
+ - batchingEnabled +
-
+
Whether to enable message batching by producers. +Messages are batched into one message according to the following properties (described in the next three entries in this list): 'batchSize',
+batchBufferLimit, andbatchTimeout. +See Batching for more information. +Also see Receiving Batched Messages.++Default:
+false.
+ - batchSize +
-
+
The number of messages to buffer when batching is enabled.
+++Default:
+100.
+ - batchBufferLimit +
-
+
The maximum buffer size when batching is enabled.
+++Default:
+10000.
+ - batchTimeout +
-
+
The batch timeout when batching is enabled.
+++Default:
+5000.
+ - bindingRoutingKey +
-
+
The routing key with which to bind the queue to the exchange (if
+bindQueueistrue). +Can be multiple keys - seebindingRoutingKeyDelimiter. +For partitioned destinations,-nis appended to each key. +Only applies ifrequiredGroupsare provided and then only to those groups.++Default:
+#.
+ - bindingRoutingKeyDelimiter +
-
+
When this is not null, 'bindingRoutingKey' is considered to be a list of keys delimited by this value; often a comma is used. +Only applies if
+requiredGroupsare provided and then only to those groups.++Default:
+null.
+ - bindQueue +
-
+
Whether to declare the queue and bind it to the destination exchange. +Set it to
+falseif you have set up your own infrastructure and have previously created and bound the queue. +Only applies ifrequiredGroupsare provided and then only to those groups.++Default:
+true.
+ - compress +
-
+
Whether data should be compressed when sent.
+++Default:
+false.
+ - confirmAckChannel +
-
+
When
+errorChannelEnabledis true, a channel to which to send positive delivery acknowledgments (aka publisher confirms). +If the channel does not exist, aDirectChannelis registered with this name. +The connection factory must be configured to enable publisher confirms.++Default:
+nullChannel(acks are discarded).
+ - deadLetterQueueName +
-
+
The name of the DLQ +Only applies if
+requiredGroupsare provided and then only to those groups.++Default:
+prefix+destination.dlq
+ - deadLetterExchange +
-
+
A DLX to assign to the queue. +Relevant only when
+autoBindDlqistrue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: 'prefix+DLX'
+
+ - deadLetterExchangeType +
-
+
The type of the DLX to assign to the queue. +Relevant only if
+autoBindDlqistrue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: 'direct'
+
+ - deadLetterRoutingKey +
-
+
A dead letter routing key to assign to the queue. +Relevant only when
+autoBindDlqistrue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default:
+destination
+ - declareDlx +
-
+
Whether to declare the dead letter exchange for the destination. +Relevant only if
+autoBindDlqistrue. +Set tofalseif you have a pre-configured DLX. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default:
+true.
+ - declareExchange +
-
+
Whether to declare the exchange for the destination.
+++Default:
+true.
+ - delayExpression +
-
+
A SpEL expression to evaluate the delay to apply to the message (
+x-delayheader). +It has no effect if the exchange is not a delayed message exchange.++Default: No
+x-delayheader is set.
+ - delayedExchange +
-
+
Whether to declare the exchange as a
+Delayed Message Exchange. +Requires the delayed message exchange plugin on the broker. +Thex-delayed-typeargument is set to theexchangeType.++Default:
+false.
+ - deliveryMode +
-
+
The delivery mode.
+++Default:
+PERSISTENT.
+ - dlqBindingArguments +
-
+
Arguments applied when binding the dlq to the dead letter exchange; used with
+headersdeadLetterExchangeTypeto specify headers to match on. +For example…dlqBindingArguments.x-match=any,…dlqBindingArguments.someHeader=someValue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: empty
+
+ - dlqDeadLetterExchange +
-
+
When a DLQ is declared, a DLX to assign to that queue. +Applies only if
+requiredGroupsare provided and then only to those groups.++Default:
+none
+ - dlqDeadLetterRoutingKey +
-
+
When a DLQ is declared, a dead letter routing key to assign to that queue. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+none
+ - dlqExpires +
-
+
How long (in milliseconds) before an unused dead letter queue is deleted. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+no expiration
+ - dlqLazy +
-
+
Declare the dead letter queue with the
+x-queue-mode=lazyargument. +See “Lazy Queues”. +Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue. +Applies only whenrequiredGroupsare provided and then only to those groups.
+ - dlqMaxLength +
-
+
Maximum number of messages in the dead letter queue. +Applies only if
+requiredGroupsare provided and then only to those groups.++Default:
+no limit
+ - dlqMaxLengthBytes +
-
+
Maximum number of total bytes in the dead letter queue from all messages. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+no limit
+ - dlqMaxPriority +
-
+
Maximum priority of messages in the dead letter queue (0-255) +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+none
+ - dlqQuorum.deliveryLimit +
-
+
When
+quorum.enabled=true, set a delivery limit after which the message is dropped or dead-lettered. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: none - broker default will apply.
+
+ - dlqQuorum.enabled +
-
+
When true, create a quorum dead letter queue instead of a classic queue. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default: false
+
+ - dlqQuorum.initialQuorumSize +
-
+
When
+quorum.enabled=true, set the initial quorum size. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: none - broker default will apply.
+
+ - dlqSingleActiveConsumer +
-
+
Set to true to set the
+x-single-active-consumerqueue property to true. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default:
+false
+ - dlqTtl +
-
+
Default time (in milliseconds) to live to apply to the dead letter queue when declared. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+no limit
+ - exchangeAutoDelete +
-
+
If
+declareExchangeistrue, whether the exchange should be auto-delete (it is removed after the last queue is removed).++Default:
+true.
+ - exchangeDurable +
-
+
If
+declareExchangeistrue, whether the exchange should be durable (survives broker restart).++Default:
+true.
+ - exchangeType +
-
+
The exchange type:
+direct,fanout,headersortopicfor non-partitioned destinations anddirect,headersortopicfor partitioned destinations.++Default:
+topic.
+ - expires +
-
+
How long (in milliseconds) before an unused queue is deleted. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+no expiration
+ - headerPatterns +
-
+
Patterns for headers to be mapped to outbound messages.
+++Default:
+['*'](all headers).
+ - lazy +
-
+
Declare the queue with the
+x-queue-mode=lazyargument. +See “Lazy Queues”. +Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default:
+false.
+ - maxLength +
-
+
Maximum number of messages in the queue. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+no limit
+ - maxLengthBytes +
-
+
Maximum number of total bytes in the queue from all messages. +Only applies if
+requiredGroupsare provided and then only to those groups.++Default:
+no limit
+ - maxPriority +
-
+
Maximum priority of messages in the queue (0-255). +Only applies if
+requiredGroupsare provided and then only to those groups.++Default:
+none
+ - prefix +
-
+
A prefix to be added to the name of the
+destinationexchange.++Default: "".
+
+ - queueBindingArguments +
-
+
Arguments applied when binding the queue to the exchange; used with
+headersexchangeTypeto specify headers to match on. +For example…queueBindingArguments.x-match=any,…queueBindingArguments.someHeader=someValue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: empty
+
+ - queueNameGroupOnly +
-
+
When
+true, consume from a queue with a name equal to thegroup. +Otherwise the queue name isdestination.group. +This is useful, for example, when using Spring Cloud Stream to consume from an existing RabbitMQ queue. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: false.
+
+ - quorum.deliveryLimit +
-
+
When
+quorum.enabled=true, set a delivery limit after which the message is dropped or dead-lettered. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: none - broker default will apply.
+
+ - quorum.enabled +
-
+
When true, create a quorum queue instead of a classic queue. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default: false
+
+ - quorum.initialQuorumSize +
-
+
When
+quorum.enabled=true, set the initial quorum size. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default: none - broker default will apply.
+
+ - routingKeyExpression +
-
+
A SpEL expression to determine the routing key to use when publishing messages. +For a fixed routing key, use a literal expression, such as
+routingKeyExpression='my.routingKey'in a properties file orroutingKeyExpression: '''my.routingKey'''in a YAML file.++Default:
+destinationordestination-<partition>for partitioned destinations.
+ - singleActiveConsumer +
-
+
Set to true to set the
+x-single-active-consumerqueue property to true. +Applies only whenrequiredGroupsare provided and then only to those groups.++Default:
+false
+ - transacted +
-
+
Whether to use transacted channels.
+++Default:
+false.
+ - ttl +
-
+
Default time (in milliseconds) to live to apply to the queue when declared. +Applies only when
+requiredGroupsare provided and then only to those groups.++Default:
+no limit
+
| + + | ++In the case of RabbitMQ, content type headers can be set by external applications. +Spring Cloud Stream supports them as part of an extended internal protocol used for any type of transport — including transports, such as Kafka (prior to 0.11), that do not natively support headers. + | +
Using Existing Queues/Exchanges
+By default, the binder will automatically provision a topic exchange with the name being derived from the value of the destination binding property <prefix><destination>.
+The destination defaults to the binding name, if not provided.
+When binding a consumer, a queue will automatically be provisioned with the name <prefix><destination>.<group> (if a group binding property is specified), or an anonymous, auto-delete queue when there is no group.
+The queue will be bound to the exchange with the "match-all" wildcard routing key (#) for a non-partitioned binding or <destination>-<instanceIndex> for a partitioned binding.
+The prefix is an empty String by default.
+If an output binding is specified with requiredGroups, a queue/binding will be provisioned for each group.
There are a number of rabbit-specific binding properties that allow you to modify this default behavior.
+If you have an existing exchange/queue that you wish to use, you can completely disable automatic provisioning as follows, assuming the exchange is named myExchange and the queue is named myQueue:
-
+
-
+
+spring.cloud.stream.bindings.<binding name>.destination=myExhange
+ -
+
+spring.cloud.stream.bindings.<binding name>.group=myQueue
+ -
+
+spring.cloud.stream.rabbit.bindings.<binding name>.consumer.bindQueue=false
+ -
+
+spring.cloud.stream.rabbit.bindings.<binding name>.consumer.declareExchange=false
+ -
+
+spring.cloud.stream.rabbit.bindings.<binding name>.consumer.queueNameGroupOnly=true
+
If you want the binder to provision the queue/exchange, but you want to do it using something other than the defaults discussed here, use the following properties. +Refer to the property documentation above for more information.
+-
+
-
+
+spring.cloud.stream.rabbit.bindings.<binding name>.consumer.bindingRoutingKey=myRoutingKey
+ -
+
+spring.cloud.stream.rabbit.bindings.<binding name>.consumer.exchangeType=<type>
+ -
+
+spring.cloud.stream.rabbit.bindings.<binding name>.producer.routingKeyExpression='myRoutingKey'
+
There are similar properties used when declaring a dead-letter exchange/queue, when autoBindDlq is true.
Retry With the RabbitMQ Binder
+When retry is enabled within the binder, the listener container thread is suspended for any back off periods that are configured. +This might be important when strict ordering is required with a single consumer. However, for other use cases, it prevents other messages from being processed on that thread. +An alternative to using binder retry is to set up dead lettering with time to live on the dead-letter queue (DLQ) as well as dead-letter configuration on the DLQ itself. +See “RabbitMQ Binder Properties” for more information about the properties discussed here. +You can use the following example configuration to enable this feature:
+-
+
-
+
Set
+autoBindDlqtotrue. +The binder create a DLQ. +Optionally, you can specify a name indeadLetterQueueName.
+ -
+
Set
+dlqTtlto the back off time you want to wait between redeliveries.
+ -
+
Set the
+dlqDeadLetterExchangeto the default exchange. +Expired messages from the DLQ are routed to the original queue, because the defaultdeadLetterRoutingKeyis the queue name (destination.group). +Setting to the default exchange is achieved by setting the property with no value, as shown in the next example.
+
To force a message to be dead-lettered, either throw an AmqpRejectAndDontRequeueException or set requeueRejected to true (the default) and throw any exception.
The loop continue without end, which is fine for transient problems, but you may want to give up after some number of attempts.
+Fortunately, RabbitMQ provides the x-death header, which lets you determine how many cycles have occurred.
To acknowledge a message after giving up, throw an ImmediateAcknowledgeAmqpException.
Putting it All Together
+The following configuration creates an exchange myDestination with queue myDestination.consumerGroup bound to a topic exchange with a wildcard routing key #:
---
+spring.cloud.stream.bindings.input.destination=myDestination
+spring.cloud.stream.bindings.input.group=consumerGroup
+#disable binder retries
+spring.cloud.stream.bindings.input.consumer.max-attempts=1
+#dlx/dlq setup
+spring.cloud.stream.rabbit.bindings.input.consumer.auto-bind-dlq=true
+spring.cloud.stream.rabbit.bindings.input.consumer.dlq-ttl=5000
+spring.cloud.stream.rabbit.bindings.input.consumer.dlq-dead-letter-exchange=
+---This configuration creates a DLQ bound to a direct exchange (DLX) with a routing key of myDestination.consumerGroup.
+When messages are rejected, they are routed to the DLQ.
+After 5 seconds, the message expires and is routed to the original queue by using the queue name as the routing key, as shown in the following example:
@SpringBootApplication
+@EnableBinding(Sink.class)
+public class XDeathApplication {
+
+ public static void main(String[] args) {
+ SpringApplication.run(XDeathApplication.class, args);
+ }
+
+ @StreamListener(Sink.INPUT)
+ public void listen(String in, @Header(name = "x-death", required = false) Map<?,?> death) {
+ if (death != null && death.get("count").equals(3L)) {
+ // giving up - don't send to DLX
+ throw new ImmediateAcknowledgeAmqpException("Failed after 4 attempts");
+ }
+ throw new AmqpRejectAndDontRequeueException("failed");
+ }
+
+}Notice that the count property in the x-death header is a Long.
Error Channels
+Starting with version 1.3, the binder unconditionally sends exceptions to an error channel for each consumer destination and can also be configured to send async producer send failures to an error channel. +See “[spring-cloud-stream-overview-error-handling]” for more information.
+RabbitMQ has two types of send failures:
+-
+
-
+
Returned messages,
+
+ -
+
Negatively acknowledged Publisher Confirms.
+
+
The latter is rare. +According to the RabbitMQ documentation "[A nack] will only be delivered if an internal error occurs in the Erlang process responsible for a queue.".
+As well as enabling producer error channels (as described in “[spring-cloud-stream-overview-error-handling]”), the RabbitMQ binder only sends messages to the channels if the connection factory is appropriately configured, as follows:
+-
+
-
+
+ccf.setPublisherConfirms(true);
+ -
+
+ccf.setPublisherReturns(true);
+
When using Spring Boot configuration for the connection factory, set the following properties:
+-
+
-
+
+spring.rabbitmq.publisher-confirms
+ -
+
+spring.rabbitmq.publisher-returns
+
The payload of the ErrorMessage for a returned message is a ReturnedAmqpMessageException with the following properties:
-
+
-
+
+failedMessage: The spring-messagingMessage<?>that failed to be sent.
+ -
+
+amqpMessage: The raw spring-amqpMessage.
+ -
+
+replyCode: An integer value indicating the reason for the failure (for example, 312 - No route).
+ -
+
+replyText: A text value indicating the reason for the failure (for example,NO_ROUTE).
+ -
+
+exchange: The exchange to which the message was published.
+ -
+
+routingKey: The routing key used when the message was published.
+
For negatively acknowledged confirmations, the payload is a NackedAmqpMessageException with the following properties:
-
+
-
+
+failedMessage: The spring-messagingMessage<?>that failed to be sent.
+ -
+
+nackReason: A reason (if available — you may need to examine the broker logs for more information).
+
There is no automatic handling of these exceptions (such as sending to a dead-letter queue). +You can consume these exceptions with your own Spring Integration flow.
+Appendices
+Appendix A: Building
+Basic Compile and Test
+To build the source you will need to install JDK 1.8.
+The build uses the Maven wrapper so you don’t have to install a specific +version of Maven. To enable the tests, you should have RabbitMQ server running +on localhost and the default port (5672) +before building.
+The main build command is
+$ ./mvnw clean install+
You can also add '-DskipTests' if you like, to avoid running the tests.
+| + + | +
+You can also install Maven (>=3.3.3) yourself and run the mvn command
+in place of ./mvnw in the examples below. If you do that you also
+might need to add -P spring if your local Maven settings do not
+contain repository declarations for spring pre-release artifacts.
+ |
+
| + + | +
+Be aware that you might need to increase the amount of memory
+available to Maven by setting a MAVEN_OPTS environment variable with
+a value like -Xmx512m -XX:MaxPermSize=128m. We try to cover this in
+the .mvn configuration, so if you find you have to do it to make a
+build succeed, please raise a ticket to get the settings added to
+source control.
+ |
+
The projects that require middleware generally include a
+docker-compose.yml, so consider using
+Docker Compose to run the middeware servers
+in Docker containers.
Documentation
+There is a "docs" profile that will generate documentation.
+./mvnw clean package -Pdocs -DskipTests
The reference documentation can then be found in docs/target/contents/reference.
Working with the code
+If you don’t have an IDE preference we would recommend that you use +Spring Tools Suite or +Eclipse when working with the code. We use the +m2eclipe eclipse plugin for maven support. Other IDEs and tools +should also work without issue.
+Importing into eclipse with m2eclipse
+We recommend the m2eclipe eclipse plugin when working with +eclipse. If you don’t already have m2eclipse installed it is available from the "eclipse +marketplace".
+Unfortunately m2e does not yet support Maven 3.3, so once the projects
+are imported into Eclipse you will also need to tell m2eclipse to use
+the .settings.xml file for the projects. If you do not do this you
+may see many different errors related to the POMs in the
+projects. Open your Eclipse preferences, expand the Maven
+preferences, and select User Settings. In the User Settings field
+click Browse and navigate to the Spring Cloud project you imported
+selecting the .settings.xml file in that project. Click Apply and
+then OK to save the preference changes.
| + + | +
+Alternatively you can copy the repository settings from .settings.xml into your own ~/.m2/settings.xml.
+ |
+
Importing into eclipse without m2eclipse
+If you prefer not to use m2eclipse you can generate eclipse project metadata using the +following command:
+$ ./mvnw eclipse:eclipse+
The generated eclipse projects can be imported by selecting import existing projects
+from the file menu.
Contributing
+Spring Cloud is released under the non-restrictive Apache 2.0 license, +and follows a very standard Github development process, using Github +tracker for issues and merging pull requests into master. If you want +to contribute even something trivial please do not hesitate, but +follow the guidelines below.
+Sign the Contributor License Agreement
+Before we accept a non-trivial patch or pull request we will need you to sign the +contributor’s agreement. +Signing the contributor’s agreement does not grant anyone commit rights to the main +repository, but it does mean that we can accept your contributions, and you will get an +author credit if we do. Active contributors might be asked to join the core team, and +given the ability to merge pull requests.
+Code Conventions and Housekeeping
+None of these is essential for a pull request, but they will all help. They can also be +added after the original pull request but before a merge.
+-
+
-
+
Use the Spring Framework code format conventions. If you use Eclipse +you can import formatter settings using the +
+eclipse-code-formatter.xmlfile from the +Spring +Cloud Build project. If using IntelliJ, you can use the +Eclipse Code Formatter +Plugin to import the same file.
+ -
+
Make sure all new
+.javafiles to have a simple Javadoc class comment with at least an +@authortag identifying you, and preferably at least a paragraph on what the class is +for.
+ -
+
Add the ASF license header comment to all new
+.javafiles (copy from existing files +in the project)
+ -
+
Add yourself as an
+@authorto the .java files that you modify substantially (more +than cosmetic changes).
+ -
+
Add some Javadocs and, if you change the namespace, some XSD doc elements.
+
+ -
+
A few unit tests would help a lot as well — someone has to do it.
+
+ -
+
If no-one else is using your branch, please rebase it against the current master (or +other target branch in the main project).
+
+ -
+
When writing a commit message please follow these conventions, +if you are fixing an existing issue please add
+Fixes gh-XXXXat the end of the commit +message (where XXXX is the issue number).
+
+
+
+
+