Today I'd like to play with ZeroMQ. ZeroMQ is a great tool to work with sockets. I will show you the problem that I want to solve: One web application needs to execute background processes but I need to execute those processes in order. Two users cannot execute one process at the same time. OK, if we face to this problem we can use Gearman. I've written various posts about Gearman (here and here for example). But today I want to play with ZeroMQ.

He uses React and some ZeroMQ bindings and Symfony's Process component to make a simple client and server for working with the queue and processes. A screencast is included in the post showing them making the connection and adding the new process. The full code can be found on github (or installable via Composer)

While waiting for a connection in Frankfurt I had a quick look at what it would take to make ZeroMQ and libevent co-exist in PHP and it was actually quite easy. Well, easy after Mikko Koppanen added a way to get the underlying socket fd from the ZeroMQ PHP extension. To get this working, install the PHP ZeroMQ extension and the PHP libevent extension.

He includes a sample script show the results of his work, a basic server and client that sends a request to the ZeroMQ server and fires off an event using the libevent library (via PHP's extension. You can find out more about using these two libraries in the PHP manual - libevent and ZeroMQ