* Reject regex search if regex string is too long (#28344)
* Add docs
* Introduce index level setting `index.max_regex_length`
to control the maximum length of the regular expression
Closes#28344
- Introduce index level settings to control the maximum number of terms
that can be used in a Terms Query
- Throw an error if a request exceeds this max number
Closes#18829
#27409 deprecated the incorrectly-spelled `levenstein` in favour of `levenshtein`.
#27526 deprecated the inconsistent `jarowinkler` in favour of `jaro_winkler`.
These changes were merged into 6.2, and this change removes them entirely in 7.0.
Queries that create a scroll context cannot use the cache.
They modify the search context during their execution so using the cache
can lead to duplicate result for the next scroll query.
This change fails the entire request if the request_cache option is explictely set
on a query that creates a scroll context (`scroll=1m`) and make sure internally that we never
use the cache for these queries when the option is not explicitely used.
For 6.x a deprecation log will be printed instead of failing the entire request and the request_cache hint
will be ignored (forced to false).