The book you are holding in your hands is an update to ElasticSearch Server, published at the beginning of 2013. Since that time, Elasticsearch has changed a lot; there are numerous improvements and massive additions in terms of functionalities, both when it comes to cluster handling and searching. After completing Mastering ElasticSearch, which covered Version 0.90 of this great search server, we decided that Version 1.0 would be a perfect time to release the updated version of our first book about Elasticsearch. Again, just like with the original book, we were not able to cover all the topics in detail. We had to choose what to describe in detail, what to mention, and what to omit in order to have a book not more than 1,000 pages long. Nevertheless, I hope that by reading this book, you'll easily learn about Elasticsearch and the underlying Apache Lucene, and that you will get the desired knowledge easily and quickly.

I would like to thank my family for the support and patience during all those days and evenings when I was sitting in front of a screen instead of being with them.

I would also like to thank all the people I'm working with at Sematext, especially Otis, who took out his time and convinced me that Sematext is the right company for me.

Finally, I would like to thank all the people involved in creating, developing, and maintaining Elasticsearch and Lucene projects for their work and passion. Without them, this book wouldn't have been written and open source search would be less powerful.

Once again, thank you all!