The MapReduce programming model makes it possible to easily parallelize a number of common batch data processing tasks and operate in large clusters without worrying about system issues like failover management
With the surge of open source projects such as Hadoop [5], adoption of the MapReduce programming model has accelerated and is moving from the research labs into real-world applications as diverse as web search, fraud detection, and online dating. Despite these advances, there is no similar trend for general-purpose distributed stream computing software
There are various projects and commercial engines , but their use is still restricted to highly specialized applications