PHP AMQP bindings

Object-oriented PHP bindings for the AMQP C library (https://github.com/alanxz/rabbitmq-c)

Requirements:

• RabbitMQ C library, commonly known as librabbitmq (since php-amqp>=1.6.0 librabbitmq >= 0.6.0 required, see release note).

Installation

Some systems has php-amqp extension in their repo or available via external repositories, so it is MAY be the preferable way to install.

If you want to stay on the bleeding edge and have the latest version, install it from PECL or compile from sources (follow PHP official docs instruction).

Documentation

stub files with accurate PHPDoc which may be also used in your IDE for code completion, navigation and documentation in-place.

Notes

• Max channels per connection means how many concurrent channels per connection may be opened at the same time (this limit may be increased later to max AMQP protocol number - 65532 without any problem).

• Nested header arrays may contain only string values.

Persistent connection

Limitations:

• there may be only one persistent connection per unique credentials (login+password+host+port+vhost). If there will be attempt to create another persistent connection with same credentials, exception will be thrown.
• channels on persistent connection are not persistent: they are destroyed between requests.
• heartbeats are limited to blocking calls only, so if there are no any operations on a connection or no active consumer set, connection may be closed by broker as dead.

Alternatively to built-in persistent connection support raphf pecl extension may be used.

How to report a problem

1. First, search through the closed issues and stackoverflow.com.
2. Submit an issue with short and definitive title that describe your problem
3. Provide platform info, php interpreter version, SAPI mode (cli, fpm, cgi, etc) extension is used in, php-amqp extension version, librabbitmq version, make tools version.
4. Description should provide information how to reproduce a problem (gist is the most preferable way to include large sources) in a definitive way. When special environment Vagrant may be in handy.
5. If stack trace generated include it in full via gist or the important part (if you are definitely know what you are doing) directly in description.

Things to check before reporting a problem

Some of them, the list is not complete.

1. You are running on correct machine in correct environment and you platform meet your application requirement.
2. librabbimq installed and discoverable in your environment so php-amqp extension can load it.
3. php-amqp extension present in system (find amqp.so or amqp.dll if you are on windows), it is loaded (php --ri amqp produced some info), and there are no underlying abstraction that MAY emulate php-amqp work.
4. You has correct RabbitMQ credentials.
5. You are using the latest php-amqp, librabbitm, RabbitMQ and sometimes PHP version itself. Sometimes your problem is already solved.
6. Other extensions disabled (especially useful when PHP interpreter crashes and you get stack trace and segmentation fault).

Development

There are vagrant environment with pre-installed software and libraries necessary to build, test and run php-amqp extension.

To start it, just type vagrant up and then vagrant ssh in php-amqp directory.

Services available out of the box are:

• Apache2 - on 192.168.33.10:8080
• nginx - on 192.168.33.10:80
• RabbitMQ on 192.168.33.10:15672

Additional tools are pre-installed to make development process as simple as possible:

• valgrind is ready to help find memory-related problems if you export TEST_PHP_ARGS=-m before running tests

• phpbrew waits to help you test extension on various PHP versions. phpbrew install 5.6 +debug+default+fpm is a nice start. To switch to some version just use phpbrew switch <version>.

  To start php-fpm just run phpbrew fpm start (don't forget to run sudo service stop php5-fpm befor).

  This development environment out of the box ready for php-fpm and cli extension usage, if need to test it when php used as apache module, refer to Apache2 support on phpbrew wiki. Keep in mind that +apxs2 conficts with +fpm and it is a bit tricky to specify which libphp .so will be loaded.

If you need to tweek RabbitMQ server params use default config rabbitmq.config.example (raw) from official RabbitmMQ repo, so it may looks like sudo curl https://raw.githubusercontent.com/rabbitmq/rabbitmq-server/master/docs/rabbitmq.config.example /etc/rabbitmq/rabbitmq.config

Keeping track of the workers

It is a good practice to keep php processes (i.e workers/consumers) under control. Usually, system administrators write their own scripts which ask services about current status or performs some desired actions. Usually request is sent via UNIX signals.
Because amqp consume method is blocking, pcntl extension seems to be useless.

php-signal-handler extension uses signal syscall, so it will work even if blocking method was executed. Some use cases are presented on extension's github page and examples are available here.