"Mastering Elasticsearch 2nd Edition" - Is it a fit for Elasticsearch 2?

Hi,

I'm thinking about buying -
Mastering Elasticsearch - Second Edition (Mastering Elasticsearch - Second Edition (English Edition) : Kuc, Rafal, Rogozinski, Marek: Amazon.de: Bücher)

I found a snippet of the bool on Google Books during a research on merge policies and it felt like it really adds some depth/detail/background to what you find on the internet, and the Elastic docs (which are great anyway..)
Also this review makes me think I would like to read it:

So, to all of you who read that book, do you think it contains sufficiently relevant facts, even if it was written for ES 1.x ? (it was published in Feb 2015)
Maybe you have some insider knowledge if there will be a new version of the book coming out next month?

Thanks for your opinion!
Uli

Hi Uli,
I don't know if a new version will be available next months.
In books about ElasticSearch, there are important parts that change for
every ElasticSearch version and some in depth parts related to Lucene
(analyzers, tokenizers, way to manage data) and architecture that don't
change.
I was asked to write my third edition of the book targeting 5.x.

The 5.x version have a lot of big changes (ingestion, "filter removing",
internl refactory, no more rivers, ...) so if you need a book in short
range take what do you like, otherwise it's better to wait books for 5.x
release that will be available in 5-6 months.

A tip for everyone: packetpub offers everyday a free ebook at
https://www.packtpub.com/packt/offers/free-learning some of ES 1.x books
are already been given free (such as mine).

Regards,
Alberto

Rivers were gone in 2.X though.

Thanks, guys, and sorry for the long silence.
Looks like, in this case, it's still worth buying the book ...

Thanks!

Honestly, I wouldn't unless I was running ES 1.X.
Only because it is now 18 months old, which is a long time when it comes to changes in ES.