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<body class="book toc2 toc-left">
<div id="header">
<div id="toc" class="toc2">
<div id="toctitle">Table of Contents</div>
<ul class="sectlevel1">
<li><a href="#_usage">Usage</a></li>
<li><a href="#_rabbitmq_binder_overview">RabbitMQ Binder Overview</a></li>
<li><a href="#_configuration_options">Configuration Options</a>
<ul class="sectlevel2">
<li><a href="#rabbit-binder-properties">RabbitMQ Binder Properties</a></li>
<li><a href="#_rabbitmq_consumer_properties">RabbitMQ Consumer Properties</a></li>
<li><a href="#_advanced_listener_container_configuration">Advanced Listener Container Configuration</a></li>
<li><a href="#_rabbit_producer_properties">Rabbit Producer Properties</a></li>
</ul>
</li>
<li><a href="#_using_existing_queuesexchanges">Using Existing Queues/Exchanges</a></li>
<li><a href="#_retry_with_the_rabbitmq_binder">Retry With the RabbitMQ Binder</a>
<ul class="sectlevel2">
<li><a href="#_putting_it_all_together">Putting it All Together</a></li>
</ul>
</li>
<li><a href="#rabbit-error-channels">Error Channels</a></li>
<li><a href="#_appendices">Appendices</a>
<ul class="sectlevel1">
<li><a href="#building">Appendix A: Building</a>
<ul class="sectlevel2">
<li><a href="#_basic_compile_and_test">Basic Compile and Test</a></li>
<li><a href="#_documentation">Documentation</a></li>
<li><a href="#_working_with_the_code">Working with the code</a></li>
</ul>
</li>
<li><a href="#contributing">Contributing</a>
<ul class="sectlevel2">
<li><a href="#_sign_the_contributor_license_agreement">Sign the Contributor License Agreement</a></li>
<li><a href="#_code_conventions_and_housekeeping">Code Conventions and Housekeeping</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="content">
<div id="preamble">
<div class="sectionbody">
<div class="imageblock">
<div class="content">
<a class="image" href="https://circleci.com/gh/spring-cloud/spring-cloud-stream-binder-rabbit"><img src="https://circleci.com/gh/spring-cloud/spring-cloud-stream-binder-rabbit.svg?style=svg" alt="CircleCI"></a>
</div>
</div>
<div class="imageblock">
<div class="content">
<a class="image" href="https://codecov.io/gh/spring-cloud/spring-cloud-stream-binder-rabbit"><img src="https://codecov.io/gh/spring-cloud/spring-cloud-stream-binder-rabbit/branch/master/graph/badge.svg" alt="codecov"></a>
</div>
</div>
<div class="imageblock">
<div class="content">
<a class="image" href="https://gitter.im/spring-cloud/spring-cloud-stream-binder-rabbit?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge"><img src="https://badges.gitter.im/spring-cloud/spring-cloud-stream-binder-rabbit.svg" alt="Gitter"></a>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_usage"><a class="link" href="#_usage">Usage</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>To use the RabbitMQ binder, you can add it to your Spring Cloud Stream application, by using the following Maven coordinates:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-xml hljs" data-lang="xml"><dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream-binder-rabbit</artifactId>
</dependency></code></pre>
</div>
</div>
<div class="paragraph">
<p>Alternatively, you can use the Spring Cloud Stream RabbitMQ Starter, as follows:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-xml hljs" data-lang="xml"><dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-stream-rabbit</artifactId>
</dependency></code></pre>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_rabbitmq_binder_overview"><a class="link" href="#_rabbitmq_binder_overview">RabbitMQ Binder Overview</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>The following simplified diagram shows how the RabbitMQ binder operates:</p>
</div>
<div class="imageblock">
<div class="content">
<img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-stream-binder-rabbit/master/docs/src/main/asciidoc/images/rabbit-binder.png" alt="rabbit binder" width="300">
</div>
<div class="title">Figure 1. RabbitMQ Binder</div>
</div>
<div class="paragraph">
<p>By default, the RabbitMQ Binder implementation maps each destination to a <code>TopicExchange</code>.
For each consumer group, a <code>Queue</code> is bound to that <code>TopicExchange</code>.
Each consumer instance has a corresponding RabbitMQ <code>Consumer</code> instance for its group’s <code>Queue</code>.
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 <code>group</code> property), an auto-delete queue (with a randomized unique name) is used.</p>
</div>
<div class="paragraph">
<p>By using the optional <code>autoBindDlq</code> option, you can configure the binder to create and configure dead-letter queues (DLQs) (and a dead-letter exchange <code>DLX</code>, as well as routing infrastructure).
By default, the dead letter queue has the name of the destination, appended with <code>.dlq</code>.
If retry is enabled (<code>maxAttempts > 1</code>), failed messages are delivered to the DLQ after retries are exhausted.
If retry is disabled (<code>maxAttempts = 1</code>), you should set <code>requeueRejected</code> to <code>false</code> (the default) so that failed messages are routed to the DLQ, instead of being re-queued.
In addition, <code>republishToDlq</code> 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 <code>x-exception-stacktrace</code> header) be added to the message in headers.
See the <a href="#spring-cloud-stream-rabbit-frame-max-headroom"><code>frameMaxHeadroom</code> property</a> 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 <a href="#spring-cloud-stream-rabbit-republish-delivery-mode"><code>republishDeliveryMode</code> property</a>.</p>
</div>
<div class="paragraph">
<p>If the stream listener throws an <code>ImmediateAcknowledgeAmqpException</code>, the DLQ is bypassed and the message simply discarded.
Starting with version 2.1, this is true regardless of the setting of <code>republishToDlq</code>; previously it was only the case when <code>republishToDlq</code> was <code>false</code>.</p>
</div>
<div class="admonitionblock important">
<table>
<tr>
<td class="icon">
<i class="fa icon-important" title="Important"></i>
</td>
<td class="content">
Setting <code>requeueRejected</code> to <code>true</code> (with <code>republishToDlq=false</code> ) 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 <code>maxAttempts</code> to greater than one or by setting <code>republishToDlq</code> to <code>true</code>.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>See <a href="#rabbit-binder-properties">RabbitMQ Binder Properties</a> for more information about these properties.</p>
</div>
<div class="paragraph">
<p>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 <a href="#rabbit-dlq-processing">[rabbit-dlq-processing]</a>.</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
When multiple RabbitMQ binders are used in a Spring Cloud Stream application, it is important to disable 'RabbitAutoConfiguration' to avoid the same configuration from <code>RabbitAutoConfiguration</code> being applied to the two binders.
You can exclude the class by using the <code>@SpringBootApplication</code> annotation.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>Starting with version 2.0, the <code>RabbitMessageChannelBinder</code> sets the <code>RabbitTemplate.userPublisherConnection</code> property to <code>true</code> so that the non-transactional producers avoid deadlocks on consumers, which can happen if cached connections are blocked because of a <a href="https://www.rabbitmq.com/memory.html">memory alarm</a> on the broker.</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
Currently, a <code>multiplex</code> 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.
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_configuration_options"><a class="link" href="#_configuration_options">Configuration Options</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>This section contains settings specific to the RabbitMQ Binder and bound channels.</p>
</div>
<div class="paragraph">
<p>For general binding configuration options and properties, see the <a href="https://github.com/spring-cloud/spring-cloud-stream/blob/master/spring-cloud-stream-core-docs/src/main/asciidoc/spring-cloud-stream-overview.adoc#configuration-options">Spring Cloud Stream core documentation</a>.</p>
</div>
<div class="sect2">
<h3 id="rabbit-binder-properties"><a class="link" href="#rabbit-binder-properties">RabbitMQ Binder Properties</a></h3>
<div class="paragraph">
<p>By default, the RabbitMQ binder uses Spring Boot’s <code>ConnectionFactory</code>.
Conseuqently, it supports all Spring Boot configuration options for RabbitMQ.
(For reference, see the <a href="https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#common-application-properties">Spring Boot documentation</a>).
RabbitMQ configuration options use the <code>spring.rabbitmq</code> prefix.</p>
</div>
<div class="paragraph">
<p>In addition to Spring Boot options, the RabbitMQ binder supports the following properties:</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">spring.cloud.stream.rabbit.binder.adminAddresses</dt>
<dd>
<p>A comma-separated list of RabbitMQ management plugin URLs.
Only used when <code>nodes</code> contains more than one entry.
Each entry in this list must have a corresponding entry in <code>spring.rabbitmq.addresses</code>.
Only needed if you use a RabbitMQ cluster and wish to consume from the node that hosts the queue.
See <a href="https://docs.spring.io/spring-amqp/reference/html/_reference.html#queue-affinity">Queue Affinity and the LocalizedQueueConnectionFactory</a> for more information.</p>
<div class="paragraph">
<p>Default: empty.</p>
</div>
</dd>
<dt class="hdlist1">spring.cloud.stream.rabbit.binder.nodes</dt>
<dd>
<p>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 <code>spring.rabbitmq.addresses</code>.
Only needed if you use a RabbitMQ cluster and wish to consume from the node that hosts the queue.
See <a href="https://docs.spring.io/spring-amqp/reference/html/_reference.html#queue-affinity">Queue Affinity and the LocalizedQueueConnectionFactory</a> for more information.</p>
<div class="paragraph">
<p>Default: empty.</p>
</div>
</dd>
<dt class="hdlist1">spring.cloud.stream.rabbit.binder.compressionLevel</dt>
<dd>
<p>The compression level for compressed bindings.
See <code>java.util.zip.Deflater</code>.</p>
<div class="paragraph">
<p>Default: <code>1</code> (BEST_LEVEL).</p>
</div>
</dd>
<dt class="hdlist1">spring.cloud.stream.binder.connection-name-prefix</dt>
<dd>
<p>A connection name prefix used to name the connection(s) created by this binder.
The name is this prefix followed by <code>#n</code>, where <code>n</code> increments each time a new connection is opened.</p>
<div class="paragraph">
<p>Default: none (Spring AMQP default).</p>
</div>
</dd>
</dl>
</div>
</div>
<div class="sect2">
<h3 id="_rabbitmq_consumer_properties"><a class="link" href="#_rabbitmq_consumer_properties">RabbitMQ Consumer Properties</a></h3>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
To avoid repetition, Spring Cloud Stream supports setting values for all channels, in the format of <code>spring.cloud.stream.default.<property>=<value></code>.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>The following properties are available for Rabbit consumers only and must be prefixed with <code>spring.cloud.stream.rabbit.bindings.<channelName>.consumer.</code>.</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">acknowledgeMode</dt>
<dd>
<p>The acknowledge mode.</p>
<div class="paragraph">
<p>Default: <code>AUTO</code>.</p>
</div>
</dd>
<dt class="hdlist1">anonymousGroupPrefix</dt>
<dd>
<p>When the binding has no <code>group</code> property, an anonymous, auto-delete queue is bound to the destination exchange.
The default naming stragegy for such queues results in a queue named <code>anonymous.<base64 representation of a UUID></code>.
Set this property to change the prefix to something other than the default.</p>
<div class="paragraph">
<p>Default: <code>anonymous.</code>.</p>
</div>
</dd>
<dt class="hdlist1">autoBindDlq</dt>
<dd>
<p>Whether to automatically declare the DLQ and bind it to the binder DLX.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">bindingRoutingKey</dt>
<dd>
<p>The routing key with which to bind the queue to the exchange (if <code>bindQueue</code> is <code>true</code>).
For partitioned destinations, <code>-<instanceIndex></code> is appended.</p>
<div class="paragraph">
<p>Default: <code>#</code>.</p>
</div>
</dd>
<dt class="hdlist1">bindQueue</dt>
<dd>
<p>Whether to declare the queue and bind it to the destination exchange.
Set it to <code>false</code> if you have set up your own infrastructure and have previously created and bound the queue.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">consumerTagPrefix</dt>
<dd>
<p>Used to create the consumer tag(s); will be appended by <code>#n</code> where <code>n</code> increments for each consumer created.
Example: <code>${spring.application.name}-${spring.cloud.stream.bindings.input.group}-${spring.cloud.stream.instance-index}</code>.</p>
<div class="paragraph">
<p>Default: none - the broker will generate random consumer tags.</p>
</div>
</dd>
<dt class="hdlist1">containerType</dt>
<dd>
<p>Select the type of listener container to be used.
See <a href="https://docs.spring.io/spring-amqp/reference/html/_reference.html#choose-container">Choosing a Container</a> in the Spring AMQP documentation for more information.</p>
<div class="paragraph">
<p>Default: <code>simple</code></p>
</div>
</dd>
<dt class="hdlist1">deadLetterQueueName</dt>
<dd>
<p>The name of the DLQ</p>
<div class="paragraph">
<p>Default: <code>prefix+destination.dlq</code></p>
</div>
</dd>
<dt class="hdlist1">deadLetterExchange</dt>
<dd>
<p>A DLX to assign to the queue.
Relevant only if <code>autoBindDlq</code> is <code>true</code>.</p>
<div class="paragraph">
<p>Default: 'prefix+DLX'</p>
</div>
</dd>
<dt class="hdlist1">deadLetterExchangeType</dt>
<dd>
<p>The type of the DLX to assign to the queue.
Relevant only if <code>autoBindDlq</code> is <code>true</code>.</p>
<div class="paragraph">
<p>Default: 'direct'</p>
</div>
</dd>
<dt class="hdlist1">deadLetterRoutingKey</dt>
<dd>
<p>A dead letter routing key to assign to the queue.
Relevant only if <code>autoBindDlq</code> is <code>true</code>.</p>
<div class="paragraph">
<p>Default: <code>destination</code></p>
</div>
</dd>
<dt class="hdlist1">declareDlx</dt>
<dd>
<p>Whether to declare the dead letter exchange for the destination.
Relevant only if <code>autoBindDlq</code> is <code>true</code>.
Set to <code>false</code> if you have a pre-configured DLX.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">declareExchange</dt>
<dd>
<p>Whether to declare the exchange for the destination.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">delayedExchange</dt>
<dd>
<p>Whether to declare the exchange as a <code>Delayed Message Exchange</code>.
Requires the delayed message exchange plugin on the broker.
The <code>x-delayed-type</code> argument is set to the <code>exchangeType</code>.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">dlqBindingArguments</dt>
<dd>
<p>Arguments applied when binding the dlq to the dead letter exchange; used with <code>headers</code> <code>deadLetterExchangeType</code> to specify headers to match on.
For example <code>…​dlqBindingArguments.x-match=any</code>, <code>…​dlqBindingArguments.someHeader=someValue</code>.</p>
<div class="paragraph">
<p>Default: empty</p>
</div>
</dd>
<dt class="hdlist1">dlqDeadLetterExchange</dt>
<dd>
<p>If a DLQ is declared, a DLX to assign to that queue.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqDeadLetterRoutingKey</dt>
<dd>
<p>If a DLQ is declared, a dead letter routing key to assign to that queue.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqExpires</dt>
<dd>
<p>How long before an unused dead letter queue is deleted (in milliseconds).</p>
<div class="paragraph">
<p>Default: <code>no expiration</code></p>
</div>
</dd>
<dt class="hdlist1">dlqLazy</dt>
<dd>
<p>Declare the dead letter queue with the <code>x-queue-mode=lazy</code> argument.
See <a href="https://www.rabbitmq.com/lazy-queues.html">“Lazy Queues”</a>.
Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">dlqMaxLength</dt>
<dd>
<p>Maximum number of messages in the dead letter queue.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">dlqMaxLengthBytes</dt>
<dd>
<p>Maximum number of total bytes in the dead letter queue from all messages.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">dlqMaxPriority</dt>
<dd>
<p>Maximum priority of messages in the dead letter queue (0-255).</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqOverflowBehavior</dt>
<dd>
<p>Action to take when <code>dlqMaxLength</code> or <code>dlqMaxLengthBytes</code> is exceeded; currently <code>drop-head</code> or <code>reject-publish</code> but refer to the RabbitMQ documentation.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqTtl</dt>
<dd>
<p>Default time to live to apply to the dead letter queue when declared (in milliseconds).</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">durableSubscription</dt>
<dd>
<p>Whether the subscription should be durable.
Only effective if <code>group</code> is also set.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">exchangeAutoDelete</dt>
<dd>
<p>If <code>declareExchange</code> is true, whether the exchange should be auto-deleted (that is, removed after the last queue is removed).</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">exchangeDurable</dt>
<dd>
<p>If <code>declareExchange</code> is true, whether the exchange should be durable (that is, it survives broker restart).</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">exchangeType</dt>
<dd>
<p>The exchange type: <code>direct</code>, <code>fanout</code>, <code>headers</code> or <code>topic</code> for non-partitioned destinations and <code>direct</code>, headers or <code>topic</code> for partitioned destinations.</p>
<div class="paragraph">
<p>Default: <code>topic</code>.</p>
</div>
</dd>
<dt class="hdlist1">exclusive</dt>
<dd>
<p>Whether to create an exclusive consumer.
Concurrency should be 1 when this is <code>true</code>.
Often used when strict ordering is required but enabling a hot standby instance to take over after a failure.
See <code>recoveryInterval</code>, which controls how often a standby instance attempts to consume.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">expires</dt>
<dd>
<p>How long before an unused queue is deleted (in milliseconds).</p>
<div class="paragraph">
<p>Default: <code>no expiration</code></p>
</div>
</dd>
<dt class="hdlist1">failedDeclarationRetryInterval</dt>
<dd>
<p>The interval (in milliseconds) between attempts to consume from a queue if it is missing.</p>
<div class="paragraph">
<p>Default: 5000</p>
</div>
</dd>
</dl>
</div>
<div id="spring-cloud-stream-rabbit-frame-max-headroom" class="dlist">
<dl>
<dt class="hdlist1">frameMaxHeadroom</dt>
<dd>
<p>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 <code>frame_max</code> size configured on the broker.
Stack traces can be large; if the size plus this property exceeds <code>frame_max</code> then the stack trace will be truncated.
A WARN log will be written; consider increasing the <code>frame_max</code> or reducing the stack trace by catching the exception and throwing one with a smaller stack trace.</p>
<div class="paragraph">
<p>Default: 20000</p>
</div>
</dd>
<dt class="hdlist1">headerPatterns</dt>
<dd>
<p>Patterns for headers to be mapped from inbound messages.</p>
<div class="paragraph">
<p>Default: <code>['*']</code> (all headers).</p>
</div>
</dd>
<dt class="hdlist1">lazy</dt>
<dd>
<p>Declare the queue with the <code>x-queue-mode=lazy</code> argument.
See <a href="https://www.rabbitmq.com/lazy-queues.html">“Lazy Queues”</a>.
Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">maxConcurrency</dt>
<dd>
<p>The maximum number of consumers.
Not supported when the <code>containerType</code> is <code>direct</code>.</p>
<div class="paragraph">
<p>Default: <code>1</code>.</p>
</div>
</dd>
<dt class="hdlist1">maxLength</dt>
<dd>
<p>The maximum number of messages in the queue.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">maxLengthBytes</dt>
<dd>
<p>The maximum number of total bytes in the queue from all messages.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">maxPriority</dt>
<dd>
<p>The maximum priority of messages in the queue (0-255).</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">missingQueuesFatal</dt>
<dd>
<p>When the queue cannot be found, whether to treat the condition as fatal and stop the listener container.
Defaults to <code>false</code> so 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.</p>
<div class="paragraph">
<p>Default: <code>false</code></p>
</div>
</dd>
<dt class="hdlist1">overflowBehavior</dt>
<dd>
<p>Action to take when <code>maxLength</code> or <code>maxLengthBytes</code> is exceeded; currently <code>drop-head</code> or <code>reject-publish</code> but refer to the RabbitMQ documentation.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">prefetch</dt>
<dd>
<p>Prefetch count.</p>
<div class="paragraph">
<p>Default: <code>1</code>.</p>
</div>
</dd>
<dt class="hdlist1">prefix</dt>
<dd>
<p>A prefix to be added to the name of the <code>destination</code> and queues.</p>
<div class="paragraph">
<p>Default: "".</p>
</div>
</dd>
<dt class="hdlist1">queueBindingArguments</dt>
<dd>
<p>Arguments applied when binding the queue to the exchange; used with <code>headers</code> <code>exchangeType</code> to specify headers to match on.
For example <code>…​queueBindingArguments.x-match=any</code>, <code>…​queueBindingArguments.someHeader=someValue</code>.</p>
<div class="paragraph">
<p>Default: empty</p>
</div>
</dd>
<dt class="hdlist1">queueDeclarationRetries</dt>
<dd>
<p>The number of times to retry consuming from a queue if it is missing.
Relevant only when <code>missingQueuesFatal</code> is <code>true</code>.
Otherwise, the container keeps retrying indefinitely.
Not supported when the <code>containerType</code> is <code>direct</code>.</p>
<div class="paragraph">
<p>Default: <code>3</code></p>
</div>
</dd>
<dt class="hdlist1">queueNameGroupOnly</dt>
<dd>
<p>When true, consume from a queue with a name equal to the <code>group</code>.
Otherwise the queue name is <code>destination.group</code>.
This is useful, for example, when using Spring Cloud Stream to consume from an existing RabbitMQ queue.</p>
<div class="paragraph">
<p>Default: false.</p>
</div>
</dd>
<dt class="hdlist1">recoveryInterval</dt>
<dd>
<p>The interval between connection recovery attempts, in milliseconds.</p>
<div class="paragraph">
<p>Default: <code>5000</code>.</p>
</div>
</dd>
<dt class="hdlist1">requeueRejected</dt>
<dd>
<p>Whether delivery failures should be re-queued when retry is disabled or <code>republishToDlq</code> is <code>false</code>.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
</dl>
</div>
<div id="spring-cloud-stream-rabbit-republish-delivery-mode" class="dlist">
<dl>
<dt class="hdlist1">republishDeliveryMode</dt>
<dd>
<p>When <code>republishToDlq</code> is <code>true</code>, specifies the delivery mode of the republished message.</p>
<div class="paragraph">
<p>Default: <code>DeliveryMode.PERSISTENT</code></p>
</div>
</dd>
<dt class="hdlist1">republishToDlq</dt>
<dd>
<p>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 <code>true</code>, 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 <a href="#spring-cloud-stream-rabbit-frame-max-headroom">frameMaxHeadroom property</a>.</p>
<div class="paragraph">
<p>Default: false</p>
</div>
</dd>
<dt class="hdlist1">transacted</dt>
<dd>
<p>Whether to use transacted channels.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">ttl</dt>
<dd>
<p>Default time to live to apply to the queue when declared (in milliseconds).</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">txSize</dt>
<dd>
<p>The number of deliveries between acks.
Not supported when the <code>containerType</code> is <code>direct</code>.</p>
<div class="paragraph">
<p>Default: <code>1</code>.</p>
</div>
</dd>
</dl>
</div>
</div>
<div class="sect2">
<h3 id="_advanced_listener_container_configuration"><a class="link" href="#_advanced_listener_container_configuration">Advanced Listener Container Configuration</a></h3>
<div class="paragraph">
<p>To set listener container properties that are not exposed as binder or binding properties, add a single bean of type <code>ListenerContainerCustomizer</code> to the application context.
The binder and binding properties will be set and then the customizer will be called.
The customizer (<code>configure()</code> method) is provided with the queue name as well as the consumer group as arguments.</p>
</div>
</div>
<div class="sect2">
<h3 id="_rabbit_producer_properties"><a class="link" href="#_rabbit_producer_properties">Rabbit Producer Properties</a></h3>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
To avoid repetition, Spring Cloud Stream supports setting values for all channels, in the format of <code>spring.cloud.stream.default.<property>=<value></code>.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>The following properties are available for Rabbit producers only and
must be prefixed with <code>spring.cloud.stream.rabbit.bindings.<channelName>.producer.</code>.</p>
</div>
<div class="dlist">
<dl>
<dt class="hdlist1">autoBindDlq</dt>
<dd>
<p>Whether to automatically declare the DLQ and bind it to the binder DLX.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">batchingEnabled</dt>
<dd>
<p>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', <code>batchBufferLimit</code>, and <code>batchTimeout</code>.
See <a href="https://docs.spring.io/spring-amqp//reference/html/_reference.html#template-batching">Batching</a> for more information.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">batchSize</dt>
<dd>
<p>The number of messages to buffer when batching is enabled.</p>
<div class="paragraph">
<p>Default: <code>100</code>.</p>
</div>
</dd>
<dt class="hdlist1">batchBufferLimit</dt>
<dd>
<p>The maximum buffer size when batching is enabled.</p>
<div class="paragraph">
<p>Default: <code>10000</code>.</p>
</div>
</dd>
<dt class="hdlist1">batchTimeout</dt>
<dd>
<p>The batch timeout when batching is enabled.</p>
<div class="paragraph">
<p>Default: <code>5000</code>.</p>
</div>
</dd>
<dt class="hdlist1">bindingRoutingKey</dt>
<dd>
<p>The routing key with which to bind the queue to the exchange (if <code>bindQueue</code> is <code>true</code>).
Only applies to non-partitioned destinations.
Only applies if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>#</code>.</p>
</div>
</dd>
<dt class="hdlist1">bindQueue</dt>
<dd>
<p>Whether to declare the queue and bind it to the destination exchange.
Set it to <code>false</code> if you have set up your own infrastructure and have previously created and bound the queue.
Only applies if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">compress</dt>
<dd>
<p>Whether data should be compressed when sent.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">confirmAckChannel</dt>
<dd>
<p>When <code>errorChannelEnabled</code> is true, a channel to which to send positive delivery acknowledgments (aka publisher confirms).
If the channel does not exist, a <code>DirectChannel</code> is registered with this name.
The connection factory must be configured to enable publisher confirms.</p>
<div class="paragraph">
<p>Default: <code>nullChannel</code> (acks are discarded).</p>
</div>
</dd>
<dt class="hdlist1">deadLetterQueueName</dt>
<dd>
<p>The name of the DLQ
Only applies if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>prefix+destination.dlq</code></p>
</div>
</dd>
<dt class="hdlist1">deadLetterExchange</dt>
<dd>
<p>A DLX to assign to the queue.
Relevant only when <code>autoBindDlq</code> is <code>true</code>.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: 'prefix+DLX'</p>
</div>
</dd>
<dt class="hdlist1">deadLetterExchangeType</dt>
<dd>
<p>The type of the DLX to assign to the queue.
Relevant only if <code>autoBindDlq</code> is <code>true</code>.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: 'direct'</p>
</div>
</dd>
<dt class="hdlist1">deadLetterRoutingKey</dt>
<dd>
<p>A dead letter routing key to assign to the queue.
Relevant only when <code>autoBindDlq</code> is <code>true</code>.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>destination</code></p>
</div>
</dd>
<dt class="hdlist1">declareDlx</dt>
<dd>
<p>Whether to declare the dead letter exchange for the destination.
Relevant only if <code>autoBindDlq</code> is <code>true</code>.
Set to <code>false</code> if you have a pre-configured DLX.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">declareExchange</dt>
<dd>
<p>Whether to declare the exchange for the destination.</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">delayExpression</dt>
<dd>
<p>A SpEL expression to evaluate the delay to apply to the message (<code>x-delay</code> header).
It has no effect if the exchange is not a delayed message exchange.</p>
<div class="paragraph">
<p>Default: No <code>x-delay</code> header is set.</p>
</div>
</dd>
<dt class="hdlist1">delayedExchange</dt>
<dd>
<p>Whether to declare the exchange as a <code>Delayed Message Exchange</code>.
Requires the delayed message exchange plugin on the broker.
The <code>x-delayed-type</code> argument is set to the <code>exchangeType</code>.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">deliveryMode</dt>
<dd>
<p>The delivery mode.</p>
<div class="paragraph">
<p>Default: <code>PERSISTENT</code>.</p>
</div>
</dd>
<dt class="hdlist1">dlqBindingArguments</dt>
<dd>
<p>Arguments applied when binding the dlq to the dead letter exchange; used with <code>headers</code> <code>deadLetterExchangeType</code> to specify headers to match on.
For example <code>…​dlqBindingArguments.x-match=any</code>, <code>…​dlqBindingArguments.someHeader=someValue</code>.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: empty</p>
</div>
</dd>
<dt class="hdlist1">dlqDeadLetterExchange</dt>
<dd>
<p>When a DLQ is declared, a DLX to assign to that queue.
Applies only if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqDeadLetterRoutingKey</dt>
<dd>
<p>When a DLQ is declared, a dead letter routing key to assign to that queue.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqExpires</dt>
<dd>
<p>How long (in milliseconds) before an unused dead letter queue is deleted.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no expiration</code></p>
</div>
</dd>
<dt class="hdlist1">dlqLazy</dt>
<dd>
<p>Declare the dead letter queue with the <code>x-queue-mode=lazy</code> argument.
See <a href="https://www.rabbitmq.com/lazy-queues.html">“Lazy Queues”</a>.
Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
</dd>
<dt class="hdlist1">dlqMaxLength</dt>
<dd>
<p>Maximum number of messages in the dead letter queue.
Applies only if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">dlqMaxLengthBytes</dt>
<dd>
<p>Maximum number of total bytes in the dead letter queue from all messages.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">dlqMaxPriority</dt>
<dd>
<p>Maximum priority of messages in the dead letter queue (0-255)
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">dlqTtl</dt>
<dd>
<p>Default time (in milliseconds) to live to apply to the dead letter queue when declared.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">exchangeAutoDelete</dt>
<dd>
<p>If <code>declareExchange</code> is <code>true</code>, whether the exchange should be auto-delete (it is removed after the last queue is removed).</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">exchangeDurable</dt>
<dd>
<p>If <code>declareExchange</code> is <code>true</code>, whether the exchange should be durable (survives broker restart).</p>
<div class="paragraph">
<p>Default: <code>true</code>.</p>
</div>
</dd>
<dt class="hdlist1">exchangeType</dt>
<dd>
<p>The exchange type: <code>direct</code>, <code>fanout</code>, <code>headers</code> or <code>topic</code> for non-partitioned destinations and <code>direct</code>, <code>headers</code> or <code>topic</code> for partitioned destinations.</p>
<div class="paragraph">
<p>Default: <code>topic</code>.</p>
</div>
</dd>
<dt class="hdlist1">expires</dt>
<dd>
<p>How long (in milliseconds) before an unused queue is deleted.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no expiration</code></p>
</div>
</dd>
<dt class="hdlist1">headerPatterns</dt>
<dd>
<p>Patterns for headers to be mapped to outbound messages.</p>
<div class="paragraph">
<p>Default: <code>['*']</code> (all headers).</p>
</div>
</dd>
<dt class="hdlist1">lazy</dt>
<dd>
<p>Declare the queue with the <code>x-queue-mode=lazy</code> argument.
See <a href="https://www.rabbitmq.com/lazy-queues.html">“Lazy Queues”</a>.
Consider using a policy instead of this setting, because using a policy allows changing the setting without deleting the queue.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">maxLength</dt>
<dd>
<p>Maximum number of messages in the queue.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">maxLengthBytes</dt>
<dd>
<p>Maximum number of total bytes in the queue from all messages.
Only applies if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
<dt class="hdlist1">maxPriority</dt>
<dd>
<p>Maximum priority of messages in the queue (0-255).
Only applies if <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>none</code></p>
</div>
</dd>
<dt class="hdlist1">prefix</dt>
<dd>
<p>A prefix to be added to the name of the <code>destination</code> exchange.</p>
<div class="paragraph">
<p>Default: "".</p>
</div>
</dd>
<dt class="hdlist1">queueBindingArguments</dt>
<dd>
<p>Arguments applied when binding the queue to the exchange; used with <code>headers</code> <code>exchangeType</code> to specify headers to match on.
For example <code>…​queueBindingArguments.x-match=any</code>, <code>…​queueBindingArguments.someHeader=someValue</code>.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: empty</p>
</div>
</dd>
<dt class="hdlist1">queueNameGroupOnly</dt>
<dd>
<p>When <code>true</code>, consume from a queue with a name equal to the <code>group</code>.
Otherwise the queue name is <code>destination.group</code>.
This is useful, for example, when using Spring Cloud Stream to consume from an existing RabbitMQ queue.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: false.</p>
</div>
</dd>
<dt class="hdlist1">routingKeyExpression</dt>
<dd>
<p>A SpEL expression to determine the routing key to use when publishing messages.
For a fixed routing key, use a literal expression, such as <code>routingKeyExpression='my.routingKey'</code> in a properties file or <code>routingKeyExpression: '''my.routingKey'''</code> in a YAML file.</p>
<div class="paragraph">
<p>Default: <code>destination</code> or <code>destination-<partition></code> for partitioned destinations.</p>
</div>
</dd>
<dt class="hdlist1">transacted</dt>
<dd>
<p>Whether to use transacted channels.</p>
<div class="paragraph">
<p>Default: <code>false</code>.</p>
</div>
</dd>
<dt class="hdlist1">ttl</dt>
<dd>
<p>Default time (in milliseconds) to live to apply to the queue when declared.
Applies only when <code>requiredGroups</code> are provided and then only to those groups.</p>
<div class="paragraph">
<p>Default: <code>no limit</code></p>
</div>
</dd>
</dl>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
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.
</td>
</tr>
</table>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_using_existing_queuesexchanges"><a class="link" href="#_using_existing_queuesexchanges">Using Existing Queues/Exchanges</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>By default, the binder will automatically provision a topic exchange with the name being derived from the value of the destination binding property <code><prefix><destination></code>.
The destination defaults to the binding name, if not provided.
When binding a consumer, a queue will automatically be provisioned with the name <code><prefix><destination>.<group></code> (if a <code>group</code> binding property is specified), or an anonymous, auto-delete queue when there is no <code>group</code>.
The queue will be bound to the exchange with the "match-all" wildcard routing key (<code>#</code>) for a non-partitioned binding or <code><destination>-<instanceIndex></code> for a partitioned binding.
The prefix is an empty <code>String</code> by default.
If an output binding is specified with <code>requiredGroups</code>, a queue/binding will be provisioned for each group.</p>
</div>
<div class="paragraph">
<p>There are a number of rabbit-specific binding properties that allow you to modify this default behavior.</p>
</div>
<div class="paragraph">
<p>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 <code>myExchange</code> and the queue is named <code>myQueue</code>:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>spring.cloud.stream.binding.<binding name>.destination=myExhange</code></p>
</li>
<li>
<p><code>spring.cloud.stream.binding.<binding name>.group=myQueue</code></p>
</li>
<li>
<p><code>spring.cloud.stream.rabbit.bindings.<binding name>.consumer.bindQueue=false</code></p>
</li>
<li>
<p><code>spring.cloud.stream.rabbit.bindings.<binding name>.consumer.declareExchange=false</code></p>
</li>
<li>
<p><code>spring.cloud.stream.rabbit.bindings.<binding name>.consumer.queueNameGroupOnly=true</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>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.</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>spring.cloud.stream.rabbit.bindings.<binding name>.consumer.bindingRoutingKey=myRoutingKey</code></p>
</li>
<li>
<p><code>spring.cloud.stream.rabbit.bindings.<binding name>.consumer.exchangeType=<type></code></p>
</li>
<li>
<p><code>spring.cloud.stream.rabbit.bindings.<binding name>.producer.routingKeyExpression='myRoutingKey'</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>There are similar properties used when declaring a dead-letter exchange/queue, when <code>autoBindDlq</code> is <code>true</code>.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_retry_with_the_rabbitmq_binder"><a class="link" href="#_retry_with_the_rabbitmq_binder">Retry With the RabbitMQ Binder</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>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 “<a href="#rabbit-binder-properties">RabbitMQ Binder Properties</a>” for more information about the properties discussed here.
You can use the following example configuration to enable this feature:</p>
</div>
<div class="ulist">
<ul>
<li>
<p>Set <code>autoBindDlq</code> to <code>true</code>.
The binder create a DLQ.
Optionally, you can specify a name in <code>deadLetterQueueName</code>.</p>
</li>
<li>
<p>Set <code>dlqTtl</code> to the back off time you want to wait between redeliveries.</p>
</li>
<li>
<p>Set the <code>dlqDeadLetterExchange</code> to the default exchange.
Expired messages from the DLQ are routed to the original queue, because the default <code>deadLetterRoutingKey</code> is the queue name (<code>destination.group</code>).
Setting to the default exchange is achieved by setting the property with no value, as shown in the next example.</p>
</li>
</ul>
</div>
<div class="paragraph">
<p>To force a message to be dead-lettered, either throw an <code>AmqpRejectAndDontRequeueException</code> or set <code>requeueRejected</code> to <code>true</code> (the default) and throw any exception.</p>
</div>
<div class="paragraph">
<p>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 <code>x-death</code> header, which lets you determine how many cycles have occurred.</p>
</div>
<div class="paragraph">
<p>To acknowledge a message after giving up, throw an <code>ImmediateAcknowledgeAmqpException</code>.</p>
</div>
<div class="sect2">
<h3 id="_putting_it_all_together"><a class="link" href="#_putting_it_all_together">Putting it All Together</a></h3>
<div class="paragraph">
<p>The following configuration creates an exchange <code>myDestination</code> with queue <code>myDestination.consumerGroup</code> bound to a topic exchange with a wildcard routing key <code>#</code>:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code>---
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=
---</code></pre>
</div>
</div>
<div class="paragraph">
<p>This configuration creates a DLQ bound to a direct exchange (<code>DLX</code>) with a routing key of <code>myDestination.consumerGroup</code>.
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:</p>
</div>
<div class="listingblock">
<div class="title">Spring Boot application</div>
<div class="content">
<pre class="highlightjs highlight"><code class="language-java hljs" data-lang="java">@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");
}
}</code></pre>
</div>
</div>
<div class="paragraph">
<p>Notice that the count property in the <code>x-death</code> header is a <code>Long</code>.</p>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="rabbit-error-channels"><a class="link" href="#rabbit-error-channels">Error Channels</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>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 “<a href="#spring-cloud-stream-overview-error-handling">[spring-cloud-stream-overview-error-handling]</a>” for more information.</p>
</div>
<div class="paragraph">
<p>RabbitMQ has two types of send failures:</p>
</div>
<div class="ulist">
<ul>
<li>
<p>Returned messages,</p>
</li>
<li>
<p>Negatively acknowledged <a href="https://www.rabbitmq.com/confirms.html">Publisher Confirms</a>.</p>
</li>
</ul>
</div>
<div class="paragraph">
<p>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.".</p>
</div>
<div class="paragraph">
<p>As well as enabling producer error channels (as described in “<a href="#spring-cloud-stream-overview-error-handling">[spring-cloud-stream-overview-error-handling]</a>”), the RabbitMQ binder only sends messages to the channels if the connection factory is appropriately configured, as follows:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>ccf.setPublisherConfirms(true);</code></p>
</li>
<li>
<p><code>ccf.setPublisherReturns(true);</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>When using Spring Boot configuration for the connection factory, set the following properties:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>spring.rabbitmq.publisher-confirms</code></p>
</li>
<li>
<p><code>spring.rabbitmq.publisher-returns</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>The payload of the <code>ErrorMessage</code> for a returned message is a <code>ReturnedAmqpMessageException</code> with the following properties:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>failedMessage</code>: The spring-messaging <code>Message<?></code> that failed to be sent.</p>
</li>
<li>
<p><code>amqpMessage</code>: The raw spring-amqp <code>Message</code>.</p>
</li>
<li>
<p><code>replyCode</code>: An integer value indicating the reason for the failure (for example, 312 - No route).</p>
</li>
<li>
<p><code>replyText</code>: A text value indicating the reason for the failure (for example, <code>NO_ROUTE</code>).</p>
</li>
<li>
<p><code>exchange</code>: The exchange to which the message was published.</p>
</li>
<li>
<p><code>routingKey</code>: The routing key used when the message was published.</p>
</li>
</ul>
</div>
<div class="paragraph">
<p>For negatively acknowledged confirmations, the payload is a <code>NackedAmqpMessageException</code> with the following properties:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>failedMessage</code>: The spring-messaging <code>Message<?></code> that failed to be sent.</p>
</li>
<li>
<p><code>nackReason</code>: A reason (if available — you may need to examine the broker logs for more information).</p>
</li>
</ul>
</div>
<div class="paragraph">
<p>There is no automatic handling of these exceptions (such as sending to a <a href="#rabbit-dlq-processing">dead-letter queue</a>).
You can consume these exceptions with your own Spring Integration flow.</p>
</div>
</div>
</div>
<h1 id="_appendices" class="sect0"><a class="link" href="#_appendices">Appendices</a></h1>
<div class="sect1">
<h2 id="building"><a class="link" href="#building">Appendix A: Building</a></h2>
<div class="sectionbody">
<div class="sect2">
<h3 id="_basic_compile_and_test"><a class="link" href="#_basic_compile_and_test">Basic Compile and Test</a></h3>
<div class="paragraph">
<p>To build the source you will need to install JDK 1.8.</p>
</div>
<div class="paragraph">
<p>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.</p>
</div>
<div class="paragraph">
<p>The main build command is</p>
</div>
<div class="listingblock">
<div class="content">
<pre>$ ./mvnw clean install</pre>
</div>
</div>
<div class="paragraph">
<p>You can also add '-DskipTests' if you like, to avoid running the tests.</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
You can also install Maven (>=3.3.3) yourself and run the <code>mvn</code> command
in place of <code>./mvnw</code> in the examples below. If you do that you also
might need to add <code>-P spring</code> if your local Maven settings do not
contain repository declarations for spring pre-release artifacts.
</td>
</tr>
</table>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
Be aware that you might need to increase the amount of memory
available to Maven by setting a <code>MAVEN_OPTS</code> environment variable with
a value like <code>-Xmx512m -XX:MaxPermSize=128m</code>. We try to cover this in
the <code>.mvn</code> 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.
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>The projects that require middleware generally include a
<code>docker-compose.yml</code>, so consider using
<a href="https://compose.docker.io/">Docker Compose</a> to run the middeware servers
in Docker containers.</p>
</div>
</div>
<div class="sect2">
<h3 id="_documentation"><a class="link" href="#_documentation">Documentation</a></h3>
<div class="paragraph">
<p>There is a "docs" profile that will generate documentation.</p>
</div>
<div class="paragraph">
<p><code>./mvnw clean package -Pdocs -DskipTests</code></p>
</div>
<div class="paragraph">
<p>The reference documentation can then be found in <code>docs/target/contents/reference</code>.</p>
</div>
</div>
<div class="sect2">
<h3 id="_working_with_the_code"><a class="link" href="#_working_with_the_code">Working with the code</a></h3>
<div class="paragraph">
<p>If you don’t have an IDE preference we would recommend that you use
<a href="https://www.springsource.com/developer/sts">Spring Tools Suite</a> or
<a href="https://eclipse.org">Eclipse</a> when working with the code. We use the
<a href="https://eclipse.org/m2e/">m2eclipe</a> eclipse plugin for maven support. Other IDEs and tools
should also work without issue.</p>
</div>
<div class="sect3">
<h4 id="_importing_into_eclipse_with_m2eclipse"><a class="link" href="#_importing_into_eclipse_with_m2eclipse">Importing into eclipse with m2eclipse</a></h4>
<div class="paragraph">
<p>We recommend the <a href="https://eclipse.org/m2e/">m2eclipe</a> eclipse plugin when working with
eclipse. If you don’t already have m2eclipse installed it is available from the "eclipse
marketplace".</p>
</div>
<div class="paragraph">
<p>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 <code>.settings.xml</code> 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 <code>.settings.xml</code> file in that project. Click Apply and
then OK to save the preference changes.</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
Alternatively you can copy the repository settings from <a href="https://github.com/spring-cloud/spring-cloud-build/blob/master/.settings.xml"><code>.settings.xml</code></a> into your own <code>~/.m2/settings.xml</code>.
</td>
</tr>
</table>
</div>
</div>
<div class="sect3">
<h4 id="_importing_into_eclipse_without_m2eclipse"><a class="link" href="#_importing_into_eclipse_without_m2eclipse">Importing into eclipse without m2eclipse</a></h4>
<div class="paragraph">
<p>If you prefer not to use m2eclipse you can generate eclipse project metadata using the
following command:</p>
</div>
<div class="listingblock">
<div class="content">
<pre>$ ./mvnw eclipse:eclipse</pre>
</div>
</div>
<div class="paragraph">
<p>The generated eclipse projects can be imported by selecting <code>import existing projects</code>
from the <code>file</code> menu.</p>
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="contributing"><a class="link" href="#contributing">Contributing</a></h2>
<div class="sectionbody">
<div class="paragraph">
<p>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.</p>
</div>
<div class="sect2">
<h3 id="_sign_the_contributor_license_agreement"><a class="link" href="#_sign_the_contributor_license_agreement">Sign the Contributor License Agreement</a></h3>
<div class="paragraph">
<p>Before we accept a non-trivial patch or pull request we will need you to sign the
<a href="https://support.springsource.com/spring_committer_signup">contributor’s agreement</a>.
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.</p>
</div>
</div>
<div class="sect2">
<h3 id="_code_conventions_and_housekeeping"><a class="link" href="#_code_conventions_and_housekeeping">Code Conventions and Housekeeping</a></h3>
<div class="paragraph">
<p>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.</p>
</div>
<div class="ulist">
<ul>
<li>
<p>Use the Spring Framework code format conventions. If you use Eclipse
you can import formatter settings using the
<code>eclipse-code-formatter.xml</code> file from the
<a href="https://github.com/spring-cloud/build/tree/master/eclipse-coding-conventions.xml">Spring
Cloud Build</a> project. If using IntelliJ, you can use the
<a href="https://plugins.jetbrains.com/plugin/6546">Eclipse Code Formatter
Plugin</a> to import the same file.</p>
</li>
<li>
<p>Make sure all new <code>.java</code> files to have a simple Javadoc class comment with at least an
<code>@author</code> tag identifying you, and preferably at least a paragraph on what the class is
for.</p>
</li>
<li>
<p>Add the ASF license header comment to all new <code>.java</code> files (copy from existing files
in the project)</p>
</li>
<li>
<p>Add yourself as an <code>@author</code> to the .java files that you modify substantially (more
than cosmetic changes).</p>
</li>
<li>
<p>Add some Javadocs and, if you change the namespace, some XSD doc elements.</p>
</li>
<li>
<p>A few unit tests would help a lot as well — someone has to do it.</p>
</li>
<li>
<p>If no-one else is using your branch, please rebase it against the current master (or
other target branch in the main project).</p>
</li>
<li>
<p>When writing a commit message please follow <a href="https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html">these conventions</a>,
if you are fixing an existing issue please add <code>Fixes gh-XXXX</code> at the end of the commit
message (where XXXX is the issue number).</p>
</li>
</ul>
</div>
</div>
</div>
</div>
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