I am trying to migrate my data from an old Elasticsearch(Version 1.4.4) Cluster to a new one (5.1)
I am using the reindex api in the new Elasticsearch, but can't get the old _timestamp to a new field timestamp. Everything else works fine.
trying to do something like this.
POST _reindex
{
  "source": {
    "remote": {
      "host": "http://oldhost:9200"
    },
    "index": "source"
    "query": {
       "match_all": {}
    }
  },
  "dest": {
    "index": "dest"
  },
  "script": {
    "lang": "painless",
    "inline": "ctx._source.timestamp = ctx._timestamp
  }
}
but the field timestamp in the new index is null.