Yothalot\Task

Yothalot was designed to run map/reduce jobs. However, since Yothalot had to be able distribute jobs over different servers for that, we decided to also support different types of jobs: like normal jobs.

The Yothalot\Task class offers you the possibility to run a single job on the yothalot cluster. This for example can be used to start more advanced map reduce jobs that need access to the glusterfs during creation.

Yothalot\Task interface

To write a task job, you have to create a class that implements this Yothalot\Task interface. This interface looks as follows:

<?php
interface Yothalot\Task
{
    public function includes();
    public function process($value);
}
?>

Serializing and unserializing

The Yothalot framework serializes and unserializes your object to distribute them over a node in the cluster. If there are any files that have to be included before the object is unserialized, you can name these files in the includes() method.

<?php
class MyTask implements Yothalot\Task
{
    /**
     *  Files that should be loaded before the object is unserialized
     *  @return string[]
     */
    public function includes()
    {
        return array(__FILE__);
    }

    // @todo implement the other methods
}
?>

PHP classes are serializable by default. If you however want to write your own custom serialize and unserialize algorithm, you can simply implement the Serializable interface:

<?php
class MyTask implements Yothalot\Task, Serializable
{
    /**
     *  Files that should be loaded before the object is unserialized
     *  @return string[]
     */
    public function includes()
    {
        return array(__FILE__);
    }

    /**
     *  Serialize the object into a string value
     *  @return string
     */
    public function serialize()
    {
        // @todo add your implementation
    }

    /**
     *  Counter part of the resize() method: turn a string back into an object
     *  @param  string
     */
    public function unserialize($input)
    {
        // @todo add your implementation
    }

    // @todo implement other methods from the 
}
?>

Processing

The final method that should be implemented is the process() method. In this method you implement your actual task. This method receives no input. You can however return values from this method to receive them later on. This output has to be serializable for this in order to work.

<?php
class MyTask implements Yothalot\Task
{
    /**
     *  Implementation for a process function
     *  @return mixed       Your return value
     */
    public function process()
    {
        // long processing job that runs on the yothalot cluster

        // output that we will return to the caller
        return array(1, 2, 3);
    }
}
?>