Including the word "advanced" in a chapter title is a little dangerous, as complexity is a subjective concept. So let's be very clear about the material covered here. We don't, for even a moment, suggest that this is the pinnacle of distilled wisdom that would otherwise take years to acquire. Conversely, we also don't claim that some of the techniques and problems covered in this chapter will have occurred to someone new to the world of Hadoop.
For the purposes of this chapter, therefore, we use the term "advanced" to cover things that you don't see in the first days or weeks, or wouldn't necessarily appreciate if you did. These are some techniques that provide both specific solutions to particular problems but also highlight ways in which the standard Hadoop and related APIs can be employed to address problems that are not obviously suited to the MapReduce processing model. Along the way, we'll also point out some alternative approaches that we don't implement...