How to update mapping of an index and apply it to the data already in the index?

[Vishal_Joshi]

I am using Elastic Search v 2.3.1 with lucene v5.5.0. I have a requirement which wants me to update the existing mapping for the index.

The index already has a lot of documents. So, I was wondering if there is a way in which only index data is backed and restored after putting new mapping in Elastic search?

I tried the snapshot and restore way https://www.elastic.co/guide/en/elasticsearch/reference/2.3/modules-snapshots.html but its brings back the old mapping and new mapping is overridden.

How can map the data already residing in index with new mapping in Elastic search?

[dadoonet (David Pilato)]

You can use the reindex API for that.

[Vishal_Joshi]

Thanks for replying and referring me reindex api.

I read it https://www.elastic.co/guide/en/elasticsearch/reference/2.3/docs-reindex.html#docs-reindex and it says it copies the snapshot. I have already tried with snapshot and it copies "data" along with "mapping" of an elastic search index.

Have I misread it? I will be trying out soon after this but does reindex copy only data?

[dadoonet (David Pilato)]

It means that it copies the index at a given point of time, whatever operations will happen while the reindex operation is running.

It will solve your problem.

[RDU]

I have the same issue.
We are running an older version of Elasticsearch (1.7) with certain mappings and analyzers. When I try to create the same mappings (via .Net components) in the newest version of Elasticsearch it fails to create. Is there a way to convert/update the mappings to the newest version. The reindex api only copies data from one index to another without mappings.