php-amqplib

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This library is a pure PHP implementation of the AMQP 0-9-1 protocol. It’s been tested against RabbitMQ.

The library was used for the PHP examples of RabbitMQ in Action and the official RabbitMQ tutorials.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.

Project Maintainers

Thanks to videlalvaro and postalservice14 for creating php-amqplib.

The package is now maintained by Ramūnas Dronga, Luke Bakken and several VMware engineers working on RabbitMQ.

Supported RabbitMQ Versions

Starting with version 2.0 this library uses AMQP 0.9.1 by default and thus requires RabbitMQ 2.0 or later version. Usually server upgrades do not require any application code changes since the protocol changes very infrequently but please conduct your own testing before upgrading.

Supported RabbitMQ Extensions

Since the library uses AMQP 0.9.1 we added support for the following RabbitMQ extensions:

• Exchange to Exchange Bindings
• Basic Nack
• Publisher Confirms
• Consumer Cancel Notify

Extensions that modify existing methods like alternate exchanges are also supported.

Related libraries

• enqueue/amqp-lib is a amqp interop compatible wrapper.

• AMQProxy is a proxy library with connection and channel pooling/reusing. This allows for lower connection and channel churn when using php-amqplib, leading to less CPU usage of RabbitMQ.

Setup

Ensure you have composer installed, then run the following command:

$ composer require php-amqplib/php-amqplib

That will fetch the library and its dependencies inside your vendor folder. Then you can add the following to your .php files in order to use the library

require_once __DIR__.'/vendor/autoload.php';

Then you need to use the relevant classes, for example:

use PhpAmqpLib\Connection\AMQPStreamConnection;
use PhpAmqpLib\Message\AMQPMessage;

Usage

With RabbitMQ running open two Terminals and on the first one execute the following commands to start the consumer:

$ cd php-amqplib/demo
$ php amqp_consumer.php

Then on the other Terminal do:

$ cd php-amqplib/demo
$ php amqp_publisher.php some text to publish

You should see the message arriving to the process on the other Terminal

Then to stop the consumer, send to it the quit message:

$ php amqp_publisher.php quit

If you need to listen to the sockets used to connect to RabbitMQ then see the example in the non blocking consumer.

$ php amqp_consumer_non_blocking.php

Change log

Please see CHANGELOG for more information what has changed recently.

API Documentation

http://php-amqplib.github.io/php-amqplib/

Tutorials

To not repeat ourselves, if you want to learn more about this library, please refer to the official RabbitMQ tutorials.

More Examples

• amqp_ha_consumer.php: demos the use of mirrored queues.
• amqp_consumer_exclusive.php and amqp_publisher_exclusive.php: demos fanout exchanges using exclusive queues.
• amqp_consumer_fanout_{1,2}.php and amqp_publisher_fanout.php: demos fanout exchanges with named queues.
• amqp_consumer_pcntl_heartbeat.php: demos signal-based heartbeat sender usage.
• basic_get.php: demos obtaining messages from the queues by using the basic get AMQP call.

Multiple hosts connections

If you have a cluster of multiple nodes to which your application can connect, you can start a connection with an array of hosts. To do that you should use the create_connection static method.

For example:

$connection = AMQPStreamConnection::create_connection([
    ['host' => HOST1, 'port' => PORT, 'user' => USER, 'password' => PASS, 'vhost' => VHOST],
    ['host' => HOST2, 'port' => PORT, 'user' => USER, 'password' => PASS, 'vhost' => VHOST]
],
$options);

This code will try to connect to HOST1 first, and connect to HOST2 if the first connection fails. The method returns a connection object for the first successful connection. Should all connections fail it will throw the exception from the last connection attempt.

See demo/amqp_connect_multiple_hosts.php for more examples.

Batch Publishing

Let’s say you have a process that generates a bunch of messages that are going to be published to the same exchange using the same routing_key and options like mandatory. Then you could make use of the batch_basic_publish library feature. You can batch messages like this:

$msg = new AMQPMessage($msg_body);
$ch->batch_basic_publish($msg, $exchange);

$msg2 = new AMQPMessage($msg_body);
$ch->batch_basic_publish($msg2, $exchange);

and then send the batch like this:

$ch->publish_batch();

When do we publish the message batch?

Let’s say our program needs to read from a file and then publish one message per line. Depending on the message size, you will have to decide when it’s better to send the batch. You could send it every 50 messages, or every hundred. That’s up to you.

Optimized Message Publishing

Another way to speed up your message publishing is by reusing the AMQPMessage message instances. You can create your new message like this:

$properties = array('content_type' => 'text/plain', 'delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT);
$msg = new AMQPMessage($body, $properties);
$ch->basic_publish($msg, $exchange);

Now let’s say that while you want to change the message body for future messages, you will keep the same properties, that is, your messages will still be text/plain and the delivery_mode will still be AMQPMessage::DELIVERY_MODE_PERSISTENT. If you create a new AMQPMessage instance for every published message, then those properties would have to be re-encoded in the AMQP binary format. You could avoid all that by just reusing the AMQPMessage and then resetting the message body like this:

$msg->setBody($body2);
$ch->basic_publish($msg, $exchange);

Truncating Large Messages

AMQP imposes no limit on the size of messages; if a very large message is received by a consumer, PHP’s memory limit may be reached within the library before the callback passed to basic_consume is called.

To avoid this, you can call the method AMQPChannel::setBodySizeLimit(int $bytes) on your Channel instance. Body sizes exceeding this limit will be truncated, and delivered to your callback with a AMQPMessage::$is_truncated flag set to true. The property AMQPMessage::$body_size will reflect the true body size of a received message, which will be higher than strlen(AMQPMessage::getBody()) if the message has been truncated.

Note that all data above the limit is read from the AMQP Channel and immediately discarded, so there is no way to retrieve it within your callback. If you have another consumer which can handle messages with larger payloads, you can use basic_reject or basic_nack to tell the server (which still has a complete copy) to forward it to a Dead Letter Exchange.

By default, no truncation will occur. To disable truncation on a Channel that has had it enabled, pass 0 (or null) to AMQPChannel::setBodySizeLimit().

Connection recovery

Some RabbitMQ clients using automated connection recovery mechanisms to reconnect and recover channels and consumers in case of network errors.

Since this client is using a single-thread, you can set up connection recovery using exception handling mechanism.

Exceptions which might be thrown in case of connection errors:

PhpAmqpLib\Exception\AMQPConnectionClosedException
PhpAmqpLib\Exception\AMQPIOException
\RuntimeException
\ErrorException

Some other exceptions might be thrown, but connection can still be there. It’s always a good idea to clean up an old connection when handling an exception before reconnecting.

For example, if you want to set up a recovering connection:

$connection = null;
$channel = null;
while(true){
    try {
        $connection = new AMQPStreamConnection(HOST, PORT, USER, PASS, VHOST);
        // Your application code goes here.
        do_something_with_connection($connection);
    } catch(AMQPRuntimeException $e) {
        echo $e->getMessage();
        cleanup_connection($connection);
        usleep(WAIT_BEFORE_RECONNECT_uS);
    } catch(\RuntimeException $e) {
        cleanup_connection($connection);
        usleep(WAIT_BEFORE_RECONNECT_uS);
    } catch(\ErrorException $e) {
        cleanup_connection($connection);
        usleep(WAIT_BEFORE_RECONNECT_uS);
    }
}

A full example is in demo/connection_recovery_consume.php.

This code will reconnect and retry the application code every time the exception occurs. Some exceptions can still be thrown and should not be handled as a part of reconnection process, because they might be application errors.

This approach makes sense mostly for consumer applications, producers will require some additional application code to avoid publishing the same message multiple times.

This was a simplest example, in a real-life application you might want to control retr count and maybe gracefully degrade wait time to reconnection.

You can find a more excessive example in #444

UNIX Signals

If you have installed PCNTL extension dispatching of signal will be handled when consumer is not processing message.

$pcntlHandler = function ($signal) {
    switch ($signal) {
        case \SIGTERM:
        case \SIGUSR1:
        case \SIGINT:
            // some stuff before stop consumer e.g. delete lock etc
            pcntl_signal($signal, SIG_DFL); // restore handler
            posix_kill(posix_getpid(), $signal); // kill self with signal, see https://www.cons.org/cracauer/sigint.html
        case \SIGHUP:
            // some stuff to restart consumer
            break;
        default:
            // do nothing
    }
};

pcntl_signal(\SIGTERM, $pcntlHandler);
pcntl_signal(\SIGINT,  $pcntlHandler);
pcntl_signal(\SIGUSR1, $pcntlHandler);
pcntl_signal(\SIGHUP,  $pcntlHandler);

To disable this feature just define constant AMQP_WITHOUT_SIGNALS as true

<?php
define('AMQP_WITHOUT_SIGNALS', true);

... more code

Signal-based Heartbeat

If you have installed PCNTL extension and are using PHP 7.1 or greater, you can register a signal-based heartbeat sender.

<?php

$sender = new PCNTLHeartbeatSender($connection);
$sender->register();
... code
$sender->unregister();

Debugging

If you want to know what’s going on at a protocol level then add the following constant to your code:

<?php
define('AMQP_DEBUG', true);

... more code

?>

Benchmarks

To run the publishing/consume benchmark type:

$ make benchmark

Tests and Contributing

Please see CONTRIBUTING for details.

Using AMQP 0.8

If you still want to use the old version of the protocol then you can do it by setting the following constant in your configuration code:

define('AMQP_PROTOCOL', '0.8');

The default value is '0.9.1'.

Providing your own autoloader

If for some reason you don’t want to use composer, then you need to have an autoloader in place fo the library classes. People have reported to use this autoloader with success.

Original README:

Below is the original README file content. Credits goes to the original authors.

PHP library implementing Advanced Message Queuing Protocol (AMQP).

The library is port of python code of py-amqplib http://barryp.org/software/py-amqplib/

It have been tested with RabbitMQ server.

Project home page: http://code.google.com/p/php-amqplib/

For discussion, please join the group:

http://groups.google.com/group/php-amqplib-devel

For bug reports, please use bug tracking system at the project page.

Patches are very welcome!

Author: Vadim Zaliva lord@crocodile.org