What does it mean when Elasticsearch cannot index something?

[arisbanach]

I've run across several errors when using Logstash's Elasticsearch output that say Elasticsearch couldn't index something because of a field mapping issue. When this happens, what exactly does this mean?

A. Elasticsearch doesn't even have the document stored in it anywhere.
B. Elasticsearch has the document and can search all the fields except for the one that mapping failed on.
C. Elasticsearch has the document but it can't search any of it at all.

I would love some more clarity on exactly what is happening with this.

[Christian_Dahlqvist]

The mapping error prevents the document from getting indexed at all (option A).

[arisbanach]

Thanks!