How to enable Sphinx Search

Sphinx is a full-text search engine that provides fast and relevant full-text search functionality.
Key Sphinx features are:

high indexing and searching performance;
advanced indexing and querying tools (flexible and feature-rich text tokenizer, querying language, several different ranking modes, etc.);
proven scalability up to billions of documents, terabytes of data, and thousands of queries per second.

Download and install Sphinx on your machine, supported version is Sphinx 2.2.11 - 2.3.2, 3.1 - 3.3
Go to KBPublisher Admin Area
Click Settings -> Plugins -> Sphinx Search tab
Check Enable Sphinx Search checkbox
Click Save

Enable Sphinx Search - On, or Off Sphinx (if Sphinx is Off - search is performed by MySQL full text)
Test Mode - if you wish to test Sphinx, you can firstly set it in a test mode. Sphinx search will be activated only by putting 'sphinx:' in front of your query, e.g. sphinx:banana
Host - Sphinx daemon host (default is 127.0.0.1)
Port - Sphinx daemon port (any free port, default is 9306)
Bin path - a directory where Sphinx is installed. You can leave it empty, but if your system does not recognize Sphinx command without path than - you should fill it, e.g. /usr/local/bin/
Data path - a directory where all Sphinx related files will be stored. Defaults to KBP cache directory, but you can change it. It should be writable by Scheduled Task (cron) user.
Version - a version number of Sphinx which you use on the computer.
Languages - set it to your language, if you have documents in another languages, select the available from the drop down list.

You can monitor how Sphinx works, what tasks are executed, what is indexed, what is added to index, etc. in Logs -> Sphinx tab