Elastic Search: The Definitive Guide by Clinton Gormley and Zachary Tong.
From “why we wrote this book:”
We wrote this book because Elasticsearch needs a narrative. The existing reference documentation is excellent… as long as you know what you are looking for. It assumes that you are intimately familiar with information retrieval concepts, distributed systems, the query DSL and a host of other topics.
This book makes no such assumptions. It has been written so that a complete beginner — to both search and distributed systems — can pick it up and start building a prototype within a few chapters.
We have taken a problem based approach: this is the problem, how do I solve it, and what are the trade-offs of the alternative solutions? We start with the basics and each chapter builds on the preceding ones, providing practical examples and explaining the theory where necessary.
The existing reference documentation explains how to use features. We want this book to explain why and when to use various features.
An important guide/reference for Elastic Search but the “why” for this book is important as well.
Reference documentation is absolutely essential but so is documentation that eases the learning curve in order to promote adoption of software or a technology.
Read this both for Elastic Search as well as one model for writing a “why” and “when” book for other technologies.