I'm trying the Reindex API from remote from an 1.7.1 ES instance to a 6.3.1. The 1.7.1 uses some indices with types, but as is documented here, these types are removed. So when I make the Reindex API action, I get some errors in "failures" section:
Rejecting mapping update to [signals-2016-12-13] as the final mapping would have more than 1 type: [1min, 10min]
I've read that it can be solved migrating multi-type indices to single type, but I'm not sure how to do it. Is this step needs to be done, in the 1.7.1 instance, before the Reindex from remote? Can it cause some problems with the existing data in this instance (1.7.1, that is the production instance)?
Thanks in advance!