MapReduce Design Patterns

Chapter 1. Design Patterns and MapReduce

MapReduce is a computing paradigm for processing data that resides on hundreds of computers, which has been popularized recently by Google, Hadoop, and many others. The paradigm is extraordinarily powerful, but it does not provide a general solution to what many are calling “big data,” so while it works particularly well on some problems, some are more challenging. This book will teach you what problems are amenable to the MapReduce paradigm, as well as how to use it effectively.

At first glance, many people do not realize that MapReduce is more of a framework than a tool. You have to fit your solution into the framework of map and reduce, which in some situations might be challenging. MapReduce is not a feature, but rather a constraint.

This makes problem solving easier and harder. It provides clear boundaries for what you can and cannot do, making the number of options you have to consider fewer than you may be used to. At the same time, figuring out how to solve a problem with constraints requires cleverness and a change in thinking.

Learning MapReduce is a lot like learning recursion for the first time: it is challenging to find the recursive solution to the problem, but when it comes to you, it is clear, concise, and elegant. In many situations you have to be conscious of system resources being used by the MapReduce job, especially inter-cluster network utilization. The tradeoff of being confined to the MapReduce framework is the ability ...