Allow excluding of fields from highlighting in Discover

[trevan]

Elasticsearch will start throwing exceptions for large fields that you try and highlight on unless you have certain settings turned on (see #16764 for more details).

It would be nice to disable highlighting on those large fields for users that don't want to modify the cluster/index settings.

[Bargs]

Thanks for filing this @trevan. This would also be a nice query optimization for users with large fields who simply don't need highlighting on everything.

The biggest question for me is how this setting should be implemented. Should it be an index pattern level setting? What if users want to control highlighting per saved search? If we implement it at the saved search level though, it takes away an admin's ability to globally disable expensive highlighting on expensive fields (or fields large enough to trigger errors in ES). Perhaps we should have both eventually, but index patterns would be a good place to start?

[trevan]

I would vote for putting it at the index pattern (or maybe even in the index mapping in elasticsearch if that is possible).

[balthazar]

Sorry to dig this up but was there any progress on disabling highlighting for some fields? Mine isn't even indexed so I would love to disable highlighting for it, as it can grow bigger than 10M in some cases.

[plumpNation]

Would love to see this feature. For those who cannot reindex easily, but do not want to take the recommended-against path of increasing index.highlight.max_analyzed_offset

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[timroes]

I am moving this over to App Services, since I believe we most likely want to exclude those fields from highlighting in index patterns, and the code for exclusion would ideally be completely inside SearchSource.

[ppisljar]

Thank you for contributing to this issue, however, we are closing this issue due to inactivity as part of a backlog grooming effort. If you believe this feature/bug should still be considered, please reopen with a comment.