I've just upgraded to ES 2.2 from 1.x and discovered that custom settings on "_id" is now deprecated more specifically "path" field.
I've found this blog which propose workaround to prevent duplicates during insert of docs:
From my point of view they are several risk with those solutions:
- the duplicate check is not stored in index settings so in case of multiple clients which are not managed you can have duplicates
- preprocessing increase load during insertion where path to unique field solved the duplication issue easily
- the duplication prevention became much more complex so implementation failure risk is important
Could you help me to find an easy ES settings side way to prevent duplicate insert in Elasticsearch 2.0 or 2.2?