Dynamic-mapped field changes type after rollover

A field in the latest backing index for a data-stream has been mapped to a different type following rollover:

  • Is it possible to re-index the current write index into a new index that would match the index pattern (i.e: from -000004 to -000005)?

  • Initially, I tried the following API call:

PUT fox-000004/_mapping
{
  "properties" : {
    "@version" : {
      "type" : "integer"
    } /* [...snip...] */
  }
}
{
  "error" : {
    "root_cause" : [
      {
        "type" : "illegal_argument_exception",
        "reason" : "mapper [@version] cannot be changed from type [keyword] to [integer]"
      }
    ],
    "type" : "illegal_argument_exception",
    "reason" : "mapper [@version] cannot be changed from type [keyword] to [integer]"
  },
  "status" : 400
}
  • How can I find which "supported mapping parameters" can be changed this way? I'm having difficulty wrapping my head around the docs which seem to imply this is possible, at least some of the time?

  • Can I predict this happening for future rollovers?

Thanks for the glance.