OpenSearch/docs/reference/analysis/analyzers/custom-analyzer.asciidoc

[[analysis-custom-analyzer]]
=== Custom Analyzer

An analyzer of type `custom` that allows to combine a `Tokenizer` with
zero or more `Token Filters`, and zero or more `Char Filters`. The
custom analyzer accepts a logical/registered name of the tokenizer to
use, and a list of logical/registered names of token filters.
The name of the custom analyzer must not start with "_".

The following are settings that can be set for a `custom` analyzer type:

[cols="<,<",options="header",]
|=======================================================================
|Setting |Description
|`tokenizer` |The logical / registered name of the tokenizer to use.

|`filter` |An optional list of logical / registered name of token
filters.

|`char_filter` |An optional list of logical / registered name of char
filters.

|`position_offset_gap` |An optional number of positions to increment 
between each field value of a field using this analyzer.
|=======================================================================

Here is an example:

[source,js]
--------------------------------------------------
index :
    analysis :
        analyzer : 
            myAnalyzer2 :
                type : custom
                tokenizer : myTokenizer1
                filter : [myTokenFilter1, myTokenFilter2]
                char_filter : [my_html]
                position_offset_gap: 256
        tokenizer :
            myTokenizer1 :
                type : standard
                max_token_length : 900
        filter :
            myTokenFilter1 :
                type : stop
                stopwords : [stop1, stop2, stop3, stop4]
            myTokenFilter2 :
                type : length
                min : 0
                max : 2000
        char_filter :
              my_html :
                type : html_strip
                escaped_tags : [xxx, yyy]
                read_ahead : 1024
--------------------------------------------------