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TheRabbitMqBundle incorporates messaging in your application viaRabbitMQ using thephp-amqplib library.

The bundle implements several messaging patterns as seen on theThumper library. Therefore publishing messages to RabbitMQ from a Symfony controller is as easy as:

$msg =array('user_id' =>1235,'image_path' =>'/path/to/new/pic.png');$this->get('old_sound_rabbit_mq.upload_picture_producer')->publish(serialize($msg));

Later when you want to consume 50 messages out of theupload_pictures queue, you just run on the CLI:

$ ./app/console rabbitmq:consumer -m 50 upload_picture

All the examples expect a running RabbitMQ server.

This bundle was presented atSymfony Live Paris 2011 conference. See the slideshere.

Due to the breaking changes happened caused by Symfony >=4.4, a new tag was released, making the bundle compatible with Symfony >=4.4.

Require the bundle and its dependencies with composer:

$ composer require php-amqplib/rabbitmq-bundle

Register the bundle:

// app/AppKernel.phppublicfunctionregisterBundles(){$bundles =array(newOldSound\RabbitMqBundle\OldSoundRabbitMqBundle(),    );}

Enjoy !

If you have a console application used to run RabbitMQ consumers, you do not need Symfony HttpKernel and FrameworkBundle.From version 1.6, you can use the Dependency Injection component to load this bundle configuration and services, and then use the consumer command.

Require the bundle in your composer.json file:

{    "require": {        "php-amqplib/rabbitmq-bundle": "^2.0",    }}

Register the extension and the compiler pass:

useOldSound\RabbitMqBundle\DependencyInjection\OldSoundRabbitMqExtension;useOldSound\RabbitMqBundle\DependencyInjection\Compiler\RegisterPartsPass;// ...$containerBuilder->registerExtension(newOldSoundRabbitMqExtension());$containerBuilder->addCompilerPass(newRegisterPartsPass());

• Since 2012-06-04 Some default options for exchanges declared in the "producers" config sectionhave changed to match the defaults of exchanges declared in the "consumers" section.The affected settings are:

  • durable was changed fromfalse totrue,
  • auto_delete was changed fromtrue tofalse.

  Your configuration must be updated if you were relying on the previous default values.

• Since 2012-04-24 The ConsumerInterface::execute method signature has changed

• Since 2012-01-03 the consumers execute method gets the whole AMQP message object and not just the body. See the CHANGELOG file for more details.

Add theold_sound_rabbit_mq section in your configuration file:

old_sound_rabbit_mq:connections:default:host:'localhost'port:5672user:'guest'password:'guest'vhost:'/'lazy:falseconnection_timeout:3read_write_timeout:3# the timeout when waiting for a response from rabbitMQ (0.0 means waits forever)channel_rpc_timeout:0.0# requires php-amqplib v2.4.1+ and PHP5.4+keepalive:false# requires php-amqplib v2.4.1+heartbeat:0#requires php_sockets.dlluse_socket:true# default falselogin_method:'AMQPLAIN'# default 'AMQPLAIN', can be 'EXTERNAL' or 'PLAIN', see https://www.rabbitmq.com/docs/access-control#mechanismsanother:# A different (unused) connection defined by an URL. One can omit all parts,# except the scheme (amqp:). If both segment in the URL and a key value (see above)# are given the value from the URL takes precedence.# See https://www.rabbitmq.com/uri-spec.html on how to encode values.url:'amqp://guest:password@localhost:5672/vhost?lazy=1&connection_timeout=6'producers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}service_alias:my_app_service# no alias by defaultdefault_routing_key:'optional.routing.key'# defaults to '' if not setdefault_content_type:'content/type'# defaults to 'text/plain'default_delivery_mode:2# optional. 1 means non-persistent, 2 means persistent. Defaults to "2".consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_serviceoptions:no_ack:false# optional. If set to "true", automatic acknowledgement mode will be used by this consumer. Default "false". See https://www.rabbitmq.com/confirms.html for details.

Here we configure the connection service and the message endpoints that our application will have. In this example your service container will contain the serviceold_sound_rabbit_mq.upload_picture_producer andold_sound_rabbit_mq.upload_picture_consumer. The later expects that there's a service calledupload_picture_service.

If you don't specify a connection for the client, the client will look for a connection with the same alias. So for ourupload_picture the service container will look for anupload_picture connection.

If you need to add optional queue arguments, then your queue options can be something like this:

queue_options:{name: 'upload-picture', arguments: {'x-ha-policy': ['S', 'all']}}

another example with message TTL of 20 seconds:

queue_options:{name: 'upload-picture', arguments: {'x-message-ttl': ['I', 20000]}}

The argument value must be a list of datatype and value. Valid datatypes are:

• S - String
• I - Integer
• D - Decimal
• T - Timestamps
• F - Table
• A - Array
• t - Bool

Adapt thearguments according to your needs.

If you want to bind queue with specific routing keys you can declare it in producer or consumer config:

queue_options:name:"upload-picture"routing_keys:      -'android.#.upload'      -'iphone.upload'

In a Symfony environment all services are fully bootstrapped for each request, from version >= 4.3 you can declarea service as lazy (Lazy Services).This bundle still doesn't support new Lazy Services feature but you can setlazy: true in your connectionconfiguration to avoid unnecessary connections to your message broker in every request.It's extremely recommended to use lazy connections because performance reasons, nevertheless lazy option is disabledby default to avoid possible breaks in applications already using this bundle.

It's a good idea to set theread_write_timeout to 2x the heartbeat so your socket will be open. If you don't do this, or use a different multiplier, there's a risk theconsumer socket will timeout.

Please bear in mind, that you can expect problems, if your tasks are generally running longer than the heartbeat period, to which there are no good solutions (link).Consider using either a big value for the heartbeat or leave the heartbeat disabled in favour of the tcp'skeepalive (both on the client and server side) and thegraceful_max_execution_timeout feature.

You can provide multiple hosts for a connection. This will allow you to use RabbitMQ cluster with multiple nodes.

old_sound_rabbit_mq:connections:default:hosts:                -host:host1port:3672user:user1password:password1vhost:vhost1                -url:'amqp://guest:password@localhost:5672/vhost'connection_timeout:3read_write_timeout:3

Pay attention that you can not specify

connection_timeoutread_write_timeoutuse_socketssl_contextkeepaliveheartbeatconnection_parameters_provider

parameters to each host separately.

Sometimes your connection information may need to be dynamic. Dynamic connection parameters allow you to supply oroverride parameters programmatically through a service.

e.g. In a scenario when thevhost parameter of the connection depends on the current tenant of your white-labeledapplication and you do not want (or can't) change it's configuration every time.

Define a service underconnection_parameters_provider that implements theConnectionParametersProviderInterface,and add it to the appropriateconnections configuration.

connections:default:host:'localhost'port:5672user:'guest'password:'guest'vhost:'foo'# to be dynamically overridden by `connection_parameters_provider`connection_parameters_provider:connection_parameters_provider_service

Example Implementation:

class ConnectionParametersProviderServiceimplements ConnectionParametersProvider {    ...publicfunctiongetConnectionParameters() {returnarray('vhost' =>$this->getVhost());    }...}

In this case, thevhost parameter will be overridden by the output ofgetVhost().

In a messaging application, the process sending messages to the broker is calledproducer while the process receiving those messages is calledconsumer. In your application you will have several of them that you can list under their respective entries in the configuration.

A producer will be used to send messages to the server. In the AMQP Model, messages are sent to anexchange, this means that in the configuration for a producer you will have to specify the connection options along with the exchange options, which usually will be the name of the exchange and the type of it.

Now let's say that you want to process picture uploads in the background. After you move the picture to its final location, you will publish a message to server with the following information:

publicfunctionindexAction($name){$msg =array('user_id' =>1235,'image_path' =>'/path/to/new/pic.png');$this->get('old_sound_rabbit_mq.upload_picture_producer')->publish(serialize($msg));}

As you can see, if in your configuration you have a producer calledupload_picture, then in the service container you will have a service calledold_sound_rabbit_mq.upload_picture_producer.

Besides the message itself, theOldSound\RabbitMqBundle\RabbitMq\Producer#publish() method also accepts an optional routing key parameter and an optional array of additional properties. The array of additional properties allows you to alter the properties with which anPhpAmqpLib\Message\AMQPMessage object gets constructed by default. This way, for example, you can change the application headers.

You can usesetContentType andsetDeliveryMode methods in order to set the message content type and the message delivery mode respectively, overriding any default set in the "producers" config section. If not overriden by either the "producers" configuration or an explicit call to these methods (as per the below example), the default values aretext/plain for content type and2 for delivery mode.

$this->get('old_sound_rabbit_mq.upload_picture_producer')->setContentType('application/json');

If you need to use a custom class for a producer (which should inherit fromOldSound\RabbitMqBundle\RabbitMq\Producer), you can use theclass option:

...producers:upload_picture:class:My\Custom\Producerconnection:defaultexchange_options:{name: 'upload-picture', type: direct}...

The next piece of the puzzle is to have a consumer that will take the message out of the queue and process it accordingly.

There are currently two events emitted by the producer.

This event occurs immediately before publishing the message. This is a good hook to do any final logging, validation, etc. before actually sending the message. A sample implementation of a listener:

namespaceApp\EventListener;useOldSound\RabbitMqBundle\Event\BeforeProducerPublishMessageEvent;useSymfony\Component\EventDispatcher\Attribute\AsEventListener;#[AsEventListener(event: BeforeProducerPublishMessageEvent::NAME)]finalclass AMQPBeforePublishEventListener{publicfunction__invoke(BeforeProducerPublishMessageEvent$event):void    {// Your code goes here    }}

This event occurs immediately after publishing the message. This is a good hook to do any confirmation logging, commits, etc. after actually sending the message. A sample implementation of a listener:

namespaceApp\EventListener;useOldSound\RabbitMqBundle\Event\AfterProducerPublishMessageEvent;useSymfony\Component\EventDispatcher\Attribute\AsEventListener;#[AsEventListener(event: AfterProducerPublishMessageEvent::NAME)]finalclass AMQPBeforePublishEventListener{publicfunction__invoke(AfterProducerPublishMessageEvent$event):void    {// Your code goes here    }}

A consumer will connect to the server and start aloop waiting for incoming messages to process. Depending on the specifiedcallback for such consumer will be the behavior it will have. Let's review the consumer configuration from above:

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_service

As we see there, thecallback option has a reference to anupload_picture_service. When the consumer gets a message from the server it will execute such callback. If for testing or debugging purposes you need to specify a different callback, then you can change it there.

Apart from the callback we also specify the connection to use, the same way as we do with aproducer. The remaining options are theexchange_options and thequeue_options. Theexchange_options should be the same ones as those used for theproducer. In thequeue_options we will provide aqueue name. Why?

As we said, messages in AMQP are published to anexchange. This doesn't mean the message has reached aqueue. For this to happen, first we need to create suchqueue and then bind it to theexchange. The cool thing about this is that you can bind severalqueues to oneexchange, in that way one message can arrive to several destinations. The advantage of this approach is thedecoupling from the producer and the consumer. The producer does not care about how many consumers will process his messages. All it needs is that his message arrives to the server. In this way we can expand the actions we perform every time a picture is uploaded without the need to change code in our controller.

Now, how to run a consumer? There's a command for it that can be executed like this:

$ ./app/console rabbitmq:consumer -m 50 upload_picture

What does this mean? We are executing theupload_picture consumer telling it to consume only 50 messages. Every time the consumer receives a message from the server, it will execute the configured callback passing the AMQP message as an instance of thePhpAmqpLib\Message\AMQPMessage class. The message body can be obtained by calling$msg->body. By default the consumer will process messages in anendless loop for some definition ofendless.

If you want to be sure that consumer will finish executing instantly on Unix signal, you can run command with flag-w.

$ ./app/console rabbitmq:consumer -w upload_picture

Then the consumer will finish executing instantly.

For using command with this flag you need to install PHP withPCNTL extension.

If you want to establish a consumer memory limit, you can do it by using flag-l. In the following example, this flag adds 256 MB memory limit. Consumer will be stopped five MB before reaching 256MB in order to avoid a PHP Allowed memory size error.

$ ./app/console rabbitmq:consumer -l 256

If you want to remove all the messages awaiting in a queue, you can execute this command to purge this queue:

$ ./app/console rabbitmq:purge --no-confirmation upload_picture

For deleting the consumer's queue, use this command:

$ ./app/console rabbitmq:delete --no-confirmation upload_picture

This can be useful in many scenarios.There are 3 AMQPEvents:

class OnConsumeEventextends AMQPEvent{constNAME = AMQPEvent::ON_CONSUME;/**     * OnConsumeEvent constructor.     *     * @param Consumer $consumer     */publicfunction__construct(Consumer$consumer)    {$this->setConsumer($consumer);    }}

Lets say you need to sleep / stop consumer/s on a new application deploy. You can listen forOldSound\RabbitMqBundle\Event\OnConsumeEvent` and check for new application deploy.

class BeforeProcessingMessageEventextends AMQPEvent{constNAME = AMQPEvent::BEFORE_PROCESSING_MESSAGE;/**     * BeforeProcessingMessageEvent constructor.     *     * @param AMQPMessage $AMQPMessage     */publicfunction__construct(Consumer$consumer,AMQPMessage$AMQPMessage)    {$this->setConsumer($consumer);$this->setAMQPMessage($AMQPMessage);    }}

Event raised before processing aAMQPMessage.

class AfterProcessingMessageEventextends AMQPEvent{constNAME = AMQPEvent::AFTER_PROCESSING_MESSAGE;/**     * AfterProcessingMessageEvent constructor.     *     * @param AMQPMessage $AMQPMessage     */publicfunction__construct(Consumer$consumer,AMQPMessage$AMQPMessage)    {$this->setConsumer($consumer);$this->setAMQPMessage($AMQPMessage);    }}

Event raised after processing aAMQPMessage.If the process message will throw an Exception the event will not raise.

<?phpclass OnIdleEventextends AMQPEvent{constNAME = AMQPEvent::ON_IDLE;/**     * OnIdleEvent constructor.     *     * @param AMQPMessage $AMQPMessage     */publicfunction__construct(Consumer$consumer)    {$this->setConsumer($consumer);$this->forceStop =true;    }}

Event raised whenwait method exit by timeout without receiving a message.In order to make use of this event a consumeridle_timeout has to beconfigured.By default process exit on idle timeout, you can prevent it by setting$event->setForceStop(false) in a listener.

If you need to set a timeout when there are no messages from your queue during a period of time, you can set theidle_timeout in seconds.Theidle_timeout_exit_code specifies what exit code should be returned by the consumer when the idle timeout occurs. Without specifying it, the consumer will throw anPhpAmqpLib\Exception\AMQPTimeoutException exception.

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_serviceidle_timeout:60idle_timeout_exit_code:0

Set thetimeout_wait in seconds.Thetimeout_wait specifies how long the consumer will wait without receiving a new message before ensuring the current connection is still valid.

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_serviceidle_timeout:60idle_timeout_exit_code:0timeout_wait:10

If you'd like your consumer to be running up to certain time and then gracefully exit, then set thegraceful_max_execution.timeout in seconds."Gracefully exit" means, that the consumer will exit either after the currently running task or immediatelly, when waiting for new tasks.Thegraceful_max_execution.exit_code specifies what exit code should be returned by the consumer when the graceful max execution timeout occurs. Without specifying it, the consumer will exit with status0.

This feature is great in conjuction with supervisord, which together can allow for periodical memory leaks cleanup, connection with database/rabbitmq renewal and more.

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_servicegraceful_max_execution:timeout:1800# 30 minutesexit_code:10# default is 0

You might have noticed that the dispatching still doesn't work exactly as we want. For example in a situation with two workers, when all odd messages are heavy and even messages are light, one worker will be constantly busy and the other one will do hardly any work. Well, RabbitMQ doesn't know anything about that and will still dispatch messages evenly.

This happens because RabbitMQ just dispatches a message when the message enters the queue. It doesn't look at the number of unacknowledged messages for a consumer. It just blindly dispatches every n-th message to the n-th consumer.

In order to defeat that we can use the basic.qos method with the prefetch_count=1 setting. This tells RabbitMQ not to give more than one message to a worker at a time. Or, in other words, don't dispatch a new message to a worker until it has processed and acknowledged the previous one. Instead, it will dispatch it to the next worker that is not still busy.

From:http://www.rabbitmq.com/tutorials/tutorial-two-python.html

Be careful as implementing the fair dispatching introduce a latency that will hurt performance (seethis blogpost). But implemeting it allow you to scale horizontally dynamically as the queue is increasing.You should evaluate, as the blogpost recommends, the right value of prefetch_size accordingly with the time taken to process each message and your network performance.

With RabbitMqBundle, you can configure that qos_options per consumer like that:

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_serviceqos_options:{prefetch_size: 0, prefetch_count: 1, global: false}

If used withSymfony 4.2+ bundle declares in container set of aliases for producers and regular consumers. Those areused for arguments autowiring based on declared type and argument name. This allows you to change previous producerexample to:

publicfunctionindexAction($name,ProducerInterface$uploadPictureProducer){$msg =array('user_id' =>1235,'image_path' =>'/path/to/new/pic.png');$uploadPictureProducer->publish(serialize($msg));}

Name of argument is constructed from producer or consumer name from configuration and suffixed with producer or consumerword according to type. In contrast to container items naming convention word suffix (producer or consumer) will not beduplicated if name is already suffixed.upload_picture producer key will be changed to$uploadPictureProducerargument name.upload_picture_producer producer key would also be aliased to$uploadPictureProducer argument name.It is best to avoid names similar in such manner.

All producers are aliased toOldSound\RabbitMqBundle\RabbitMq\ProducerInterface and producer class option fromconfiguration. In sandbox mode onlyProducerInterface aliases are made. It is highly recommended to useProducerInterfaceclass when type hinting arguments for producer injection.

All consumers are aliased toOldSound\RabbitMqBundle\RabbitMq\ConsumerInterface and%old_sound_rabbit_mq.consumer.class%configuration option value. There is no difference between regular and sandbox mode. It is highly recommended to useConsumerInterface when type hinting arguments for client injection.

Here's an example callback:

<?php//src/Acme/DemoBundle/Consumer/UploadPictureConsumer.phpnamespaceAcme\DemoBundle\Consumer;useOldSound\RabbitMqBundle\RabbitMq\ConsumerInterface;usePhpAmqpLib\Message\AMQPMessage;class UploadPictureConsumerimplements ConsumerInterface{publicfunctionexecute(AMQPMessage$msg)    {//Process picture upload.//$msg will be an instance of `PhpAmqpLib\Message\AMQPMessage` with the $msg->body being the data sent over RabbitMQ.$isUploadSuccess =someUploadPictureMethod();if (!$isUploadSuccess) {// If your image upload failed due to a temporary error you can return false// from your callback so the message will be rejected by the consumer and// requeued by RabbitMQ.// Any other value not equal to false will acknowledge the message and remove it// from the queuereturnfalse;        }    }}

As you can see, this is as simple as implementing one method:ConsumerInterface::execute.

Keep in mind that your callbacksneed to be registered as normal Symfony services. There you can inject the service container, the database service, the Symfony logger, and so on.

Seehttps://github.com/php-amqplib/php-amqplib/blob/master/doc/AMQPMessage.md for more details of what's part of a message instance.

To stop the consumer, callback can throwStopConsumerException (the last consumed messagewill not be ack) orAckStopConsumerException (the messagewill be ack). If using demonized, ex: supervisor, the consumer will actually restart.

This seems to be quite a lot of work for just sending messages, let's recap to have a better overview. This is what we need to produce/consume messages:

• Add an entry for the consumer/producer in the configuration.
• Implement your callback.
• Start the consumer from the CLI.
• Add the code to publish messages inside the controller.

And that's it!

This was a requirement to have a traceability of messages received/published.In order to enable this you'll need to addenable_logger config to consumers or publishers.

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture'}callback:upload_picture_serviceenable_logger:true

If you would like you can also treat logging from queues with different handlers in monolog, by referencing channelphpamqplib.

So far we just have sent messages to consumers, but what if we want to get a reply from them? To achieve this we have to implement RPC calls into our application. This bundle makes it pretty easy to achieve such things with Symfony.

Let's add a RPC client and server into the configuration:

rpc_clients:integer_store:connection:default#default: defaultunserializer:json_decode#default: unserializelazy:true#default: falsedirect_reply_to:falserpc_servers:random_int:connection:defaultcallback:random_int_serverqos_options:{prefetch_size: 0, prefetch_count: 1, global: false}exchange_options:{name: random_int, type: topic}queue_options:{name: random_int_queue, durable: false, auto_delete: true}serializer:json_encode

For a full configuration reference please use thephp app/console config:dump-reference old_sound_rabbit_mq command.

Here we have a very useful server: it returns random integers to its clients. The callback used to process the request will be therandom_int_server service. Now let's see how to invoke it from our controllers.

First we have to start the server from the command line:

$ ./app/console_dev rabbitmq:rpc-server random_int

And then add the following code to our controller:

publicfunctionindexAction($name){$client =$this->get('old_sound_rabbit_mq.integer_store_rpc');$client->addRequest(serialize(array('min' =>0,'max' =>10)),'random_int','request_id');$replies =$client->getReplies();}

As you can see there, if our client id isinteger_store, then the service name will beold_sound_rabbit_mq.integer_store_rpc. Once we get that object we place a request on the server by callingaddRequest that expects three parameters:

• The arguments to be sent to the remote procedure call.
• The name of the RPC server, in our caserandom_int.
• A request identifier for our call, in this caserequest_id.

The arguments we are sending are themin andmax values for therand() function. We send them by serializing an array. If our server expects JSON information, or XML, we will send such data here.

The final piece is to get the reply. Our PHP script will block till the server returns a value. The$replies variable will be an associative array where each reply from the server will contained in the respectiverequest_id key.

By default the RPC Client expects the response to be serialized. If the server you are working with returns a non-serialized result then set the RPC clientexpect_serialized_response option to false. For example, if theinteger_store server didn't serialize the result the client would be set as below:

rpc_clients:integer_store:connection:defaultexpect_serialized_response:false

You can also set a expiration for request in milliseconds, after which message will no longer be handled by server and client request will simply time out. Setting expiration for messages works only for RabbitMQ 3.x and above. Visithttp://www.rabbitmq.com/ttl.html#per-message-ttl for more information.

publicfunctionindexAction($name){$expiration =5000;// milliseconds$client =$this->get('old_sound_rabbit_mq.integer_store_rpc');$client->addRequest($body,$server,$requestId,$routingKey,$expiration);try {$replies =$client->getReplies();// process $replies['request_id'];    }catch (\PhpAmqpLib\Exception\AMQPTimeoutException$e) {// handle timeout    }}

As you can guess, we can also makeparallel RPC calls.

Let's say that for rendering some webpage, you need to perform two database queries, one taking 5 seconds to complete and the other one taking 2 seconds –very expensive queries–. If you execute them sequentially, then your page will be ready to deliver in about 7 seconds. If you run them in parallel then you will have your page served in about 5 seconds. WithRabbitMqBundle we can do such parallel calls with ease. Let's define a parallel client in the config and another RPC server:

rpc_clients:parallel:connection:defaultrpc_servers:char_count:connection:defaultcallback:char_count_serverrandom_int:connection:defaultcallback:random_int_server

Then this code should go in our controller:

publicfunctionindexAction($name){$client =$this->get('old_sound_rabbit_mq.parallel_rpc');$client->addRequest($name,'char_count','char_count');$client->addRequest(serialize(array('min' =>0,'max' =>10)),'random_int','random_int');$replies =$client->getReplies();}

Is very similar to the previous example, we just have an extraaddRequest call. Also we provide meaningful request identifiers so later will be easier for us to find the reply we want in the$replies array.

To enabledirect reply-to clients you just have to enable optiondirect_reply_to on therpc_clients configuration for the client.

This option will use pseudo-queueamq.rabbitmq.reply-to when doing RPC calls. On the RPC server there is no modification needed.

RabbitMQ has priority queue implementation in the core as of version 3.5.0. Any queue can be turned into a priority one using client-provided optional arguments (but, unlike other features that use optional arguments, not policies).The implementation supports a limited number of priorities: 255. Values between 1 and 10 are recommended.Check documentation

here is how you can declare a priority queue

consumers:upload_picture:connection:defaultexchange_options:{name: 'upload-picture', type: direct}queue_options:{name: 'upload-picture', arguments: {'x-max-priority': ['I', 10]} }callback:upload_picture_service

ifupload-picture queue exist before you must delete this queue before you runrabbitmq:setup-fabric command

Now let's say you want to make a message with high priority, you have to publish the message with this additional information

publicfunctionindexAction(){$msg =array('user_id' =>1235,'image_path' =>'/path/to/new/pic.png');$additionalProperties = ['priority' =>10] ;$routing_key ='';$this->get('old_sound_rabbit_mq.upload_picture_producer')->publish(serialize($msg),$routing_key ,$additionalProperties );}

It's a good practice to have a lot of queues for logic separation. With a simple consumer you will have to create one worker (consumer) per queue and it can be hard to manage when dealingwith many evolutions (forget to add a line in your supervisord configuration?). This is also useful for small queues as you may not want to have as many workers as queues, and want to regroupsome tasks together without losing flexibility and separation principle.

Multiple consumers allow you to handle this use case by listening to multiple queues on the same consumer.

Here is how you can set a consumer with multiple queues:

multiple_consumers:upload:connection:defaultexchange_options:{name: 'upload', type: direct}queues_provider:queues_provider_servicequeues:upload-picture:name:upload_picturecallback:upload_picture_servicerouting_keys:                    -pictureupload-video:name:upload_videocallback:upload_video_servicerouting_keys:                    -videoupload-stats:name:upload_statscallback:upload_stats

The callback is now specified under each queues and must implement theConsumerInterface like a simple consumer.All the options ofqueues-options in the consumer are available for each queue.

Be aware that all queues are under the same exchange, it's up to you to set the correct routing for callbacks.

Thequeues_provider is a optional service that dynamically provides queues.It must implementQueuesProviderInterface.

Be aware that queues providers are responsible for the proper calls tosetDequeuer and that callbacks are callables(notConsumerInterface). In case service providing queues implementsDequeuerAwareInterface, a call tosetDequeuer is added to the definition of the service with aDequeuerInterface currently being aMultipleConsumer.

You may find that your application has a complex workflow and you need to have arbitrary binding. Arbitrarybinding scenarios might include exchange to exchange bindings viadestination_is_exchange property.

bindings:    -{exchange: foo, destination: bar, routing_key: 'baz.*' }    -{exchange: foo1, destination: foo, routing_key: 'baz.*', destination_is_exchange: true}

The rabbitmq:setup-fabric command will declare exchanges and queues as defined in your producer, consumerand multi consumer configurations before it creates your arbitrary bindings. However, the rabbitmq:setup-fabric willNOT declare addition queues and exchanges defined in the bindings. It's up to you to make sure exchanges/queues are declared.

Sometimes you have to change the consumer's configuration on the fly.Dynamic consumers allow you to define the consumers queue options programmatically, based on the context.

e.g. In a scenario when the defined consumer must be responsible for a dynamic number of topics and you do not want (or can't) change it's configuration every time.

Define a servicequeue_options_provider that implements theQueueOptionsProviderInterface, and add it to yourdynamic_consumers configuration.

dynamic_consumers:proc_logs:connection:defaultexchange_options:{name: 'logs', type: topic}callback:parse_logs_servicequeue_options_provider:queue_options_provider_service

Example Usage:

$ ./app/console rabbitmq:dynamic-consumer proc_logs server1

In this case theproc_logs consumer runs forserver1 and it can decide over the queue options it uses.

Now, why will we ever need anonymous consumers? This sounds like some internet threat or something… Keep reading.

In AMQP there's a type of exchange calledtopic where the messages are routed to queues based on –you guess– the topic of the message. We can send logs about our application to a RabbiMQ topic exchange using as topic the hostname where the log was created and the severity of such log. The message body will be the log content and our routing keys the will be like this:

• server1.error
• server2.info
• server1.warning
• ...

Since we don't want to be filling up queues with unlimited logs what we can do is that when we want to monitor the system, we can launch a consumer that creates a queue and attaches to thelogs exchange based on some topic, for example, we would like to see all the errors reported by our servers. The routing key will be something like:#.error. In such case we have to come up with a queue name, bind it to the exchange, get the logs, unbind it and delete the queue. Happily AMPQ provides a way to do this automatically if you provide the right options when you declare and bind the queue. The problem is that you don't want to remember all those options. For such reason we implemented theAnonymous Consumer pattern.

When we start an Anonymous Consumer, it will take care of such details and we just have to think about implementing the callback for when the messages arrive. Is it called Anonymous because it won't specify a queue name, but it will wait for RabbitMQ to assign a random one to it.

Now, how to configure and run such consumer?

anon_consumers:logs_watcher:connection:defaultexchange_options:{name: 'app-logs', type: topic}callback:logs_watcher

There we specify the exchange name and it's type along with the callback that should be executed when a message arrives.

This Anonymous Consumer is now able to listen to Producers, which are linked to the same exchange and of typetopic:

producers:app_logs:connection:defaultexchange_options:{name: 'app-logs', type: topic}

To start anAnonymous Consumer we use the following command:

$ ./app/console_dev rabbitmq:anon-consumer -m 5 -r'#.error' logs_watcher

The only new option compared to the commands that we have seen before is the one that specifies therouting key:-r '#.error'.

In some cases you will want to get a batch of messages and then do some processing on all of them. Batch consumers will allow you to define logic for this type of processing.

e.g: Imagine that you have a queue where you receive a message for inserting some information in the database, and you realize that if you do a batch insert is much better then by inserting one by one.

Define a callback service that implementsBatchConsumerInterface and add the definition of the consumer to your configuration.

batch_consumers:batch_basic_consumer:connection:defaultexchange_options:{name: 'batch', type: fanout}queue_options:{name: 'batch'}callback:batch.basicqos_options:{prefetch_size: 0, prefetch_count: 2, global: false}timeout_wait:5auto_setup_fabric:falseidle_timeout_exit_code:-2keep_alive:falsegraceful_max_execution:timeout:60

Note: If thekeep_alive option is set totrue,idle_timeout_exit_code will be ignored and the consumer process continues.

You can implement a batch consumer that will acknowledge all messages in one return or you can have control on what message to acknowledge.

namespaceAppBundle\Service;useOldSound\RabbitMqBundle\RabbitMq\BatchConsumerInterface;usePhpAmqpLib\Message\AMQPMessage;class DevckBasicConsumerimplements BatchConsumerInterface{/**     * @inheritDoc     */publicfunctionbatchExecute(array$messages)    {echosprintf('Doing batch execution%s',PHP_EOL);foreach ($messagesas$message) {$this->executeSomeLogicPerMessage($message);        }// you ack all messages got in batchreturntrue;     }}

namespaceAppBundle\Service;useOldSound\RabbitMqBundle\RabbitMq\BatchConsumerInterface;usePhpAmqpLib\Message\AMQPMessage;class DevckBasicConsumerimplements BatchConsumerInterface{/**     * @inheritDoc     */publicfunctionbatchExecute(array$messages)    {echosprintf('Doing batch execution%s',PHP_EOL);$result = [];/** @var AMQPMessage $message */foreach ($messagesas$message) {$result[$message->getDeliveryTag()] =$this->executeSomeLogicPerMessage($message);        }// you ack only some messages that have return true// e.g:// $return = [//      1 => true,//      2 => true,//      3 => false,//      4 => true,//      5 => -1,//      6 => 2,//  ];// The following will happen://  * ack: 1,2,4//  * reject and requeq: 3//  * nack and requeue: 6//  * reject and drop: 5return$result;    }}

How to run the following batch consumer:

    $ ./bin/console rabbitmq:batch:consumer batch_basic_consumer -w

Important: BatchConsumers will not have the-m|messages option availableImportant: BatchConsumers can also have the-b|batches option available if you want to only consume a specific number of batches and then stop the consumer. Give the number of the batches only if you want the consumer to stop after those batch messages were consumed!

There's a Command that reads data from STDIN and publishes it to a RabbitMQ queue. To use it first you have to configure aproducer service in your configuration file like this:

producers:words:connection:defaultexchange_options:{name: 'words', type: direct}

That producer will publish messages to thewords direct exchange. Of course you can adapt the configuration to whatever you like.

Then let's say you want to publish the contents of some XML files so they are processed by a farm of consumers. You could publish them by just using a command like this:

$ find vendor/symfony/ -name"*.xml" -print0| xargs -0 cat| ./app/console rabbitmq:stdin-producer words

This means you can compose producers with plain Unix commands.

Let's decompose that one liner:

$ find vendor/symfony/ -name"*.xml" -print0

That command will find all the.xml files inside the symfony folder and will print the file name. Each of those file names is thenpiped tocat viaxargs:

$ xargs -0 cat

And finally the output ofcat goes directly to our producer that is invoked like this:

$ ./app/console rabbitmq:stdin-producer words

It takes only one argument which is the name of the producer as you configured it in yourconfig.yml file.

The purpose of this bundle is to let your application produce messages and publish them to some exchanges you configured.

In some cases and even if your configuration is right, the messages you are producing will not be routed to any queue because none exist. The consumer responsible for the queue consumption has to be run for the queue to be created.

Launching a command for each consumer can be a nightmare when the number of consumers is high.

In order to create exchanges, queues and bindings at once and be sure you will not lose any message, you can run the following command:

$ ./app/console rabbitmq:setup-fabric

When desired, you can configure your consumers and producers to assume the RabbitMQ fabric is already defined. To do this, add the following to your configuration:

producers:upload_picture:auto_setup_fabric:falseconsumers:upload_picture:auto_setup_fabric:false

By default a consumer or producer will declare everything it needs with RabbitMQ when it starts.Be careful using this, when exchanges or queues are not defined, there will be errors. When you've changed any configuration you need to run the above setup-fabric command to declare your configuration.

To contribute just open a Pull Request with your new code taking into account that if you add new features or modify existing ones you have to document in this README what they do. If you break BC then you have to document it as well. Also you have to update the CHANGELOG. So:

• Document New Features.
• Update CHANGELOG.
• Document BC breaking changes.

See: resources/meta/LICENSE.md

The bundle structure and the documentation is partially based on theRedisBundle