How do I use the RabbitMQ delayed message queue from PHP?

Question

I'm trying to use the Delayed Message Queue for RabbitMQ from PHP, but my messages are simply disappearing.

I'm declaring the exchange with the following code:

$this->channel->exchange_declare(
    'delay',
    'x-delayed-message',
    false,  /* passive, create if exchange doesn't exist */
    true,   /* durable, persist through server reboots */
    false,  /* autodelete */
    false,  /* internal */
    false,  /* nowait */
    ['x-delayed-type' => ['S', 'direct']]);

I'm binding the queue with this code:

$this->channel->queue_declare(
    $queueName,
    false,  /* Passive */
    true,   /* Durable */
    false,  /* Exclusive */
    false   /* Auto Delete */
);
$this->channel->queue_bind($queueName, "delay", $queueName);

And I'm publishing a message with this code:

$msg = new AMQPMessage(json_encode($msgData), [
    'delivery_mode' => 2,
    'x-delay' => 5000]);
$this->channel->basic_publish($msg, 'delay', $queueName);

But the message doesn't get delayed; it's still immediately delivered. What am I missing?

Answer 1

From here,

The message creation should be

require_once __DIR__ . '/vendor/autoload.php';
use PhpAmqpLib\Message\AMQPMessage;
use PhpAmqpLib\Wire\AMQPTable;

$msg = new AMQPMessage($data,
            array(
                'delivery_mode' => 2, # make message persistent
                'application_headers' => new AMQPTable([
                    'x-delay' => 5000
                ])
            )
        );

Answer 2

The answer is for those who need message delaying but does not want to dig into details. You need only a few things to get it working:

Install amqp interop compatible transport for example enqueue/amqp-bunny and enqueue/amqp-tools.

composer require enqueue/amqp-bunny enqueue/amqp-tools

Create amqp context, add a delay strategy and send delayed messages:

<?php
use Enqueue\AmqpTools\RabbitMqDelayPluginDelayStrategy;
use Enqueue\AmqpBunny\AmqpConnectionFactory;

$context = (new AmqpConnectionFactory('amqp://'))->createContext();
$context->setDelayStrategy(new RabbitMqDelayPluginDelayStrategy())

$queue = $context->createQueue('foo');
$context->declareQueue($queue);

$message = $context->createMessage('Hello world!');

$context->createProducer()
    ->setDeliveryDelay(5000) // 5 sec
    ->send($queue, $message)
;

By the way, this not the only strategy available. there is one based on RabbitMQ dead letter queues + ttl. It could be used the same way.