Cluster load while updating mappings of live production indexes

[ginopino]

Hello!
I need to add a couple of new keyword fields to a significant quantity of production indexes which are using a mapping with dynamic: strict
I was hoping to be able to use a wildcard with the update mapping API, something like

PUT /my-index-prefix-*/_mapping
{
  "properties": {
    "email": {
      "type": "keyword"
    }
  }
}

I am concerned about the safety of running this against heavily used production indexes. Should I expect some kind of impact on the cluster performance while the mappings are updated?

thanks

[warkolm (Mark Walkom)]

Welcome to our community!

Yes, there is a cost to doing this, so it'll likely impact your cluster traffic.

[ginopino]

Hi Mark, thank you for your answer!
Is there a recommended way for doing this while minimizing the performance impact? Maybe applying updates to one index at a time instead of using a wildcard update?
Or it's better to create new indexes with the updated mapping and then perform a reindex?

many thanks

[warkolm (Mark Walkom)]

I'd start by doing a few, and then seeing what sort of impact it has.
Ultimately it'll depend on how many indices are being updated.

[ginopino]

ok, thanks I'll give it a try!