Is it possible to increase "index.mapping.total_fields.limit" in Amazon OpenSearch to 2500? (Its default value is 1000)

Have you tried changing the index.mapping.total_fields.limit setting, you need to update the index settings using the OpenSearch API. Here is an example of how you can do this. Let me know the results of this setting change.

Create a new index with the updated setting:

PUT /my-index
{
  "settings": {
    "index.mapping.total_fields.limit": 2500
  }
}

Update an existing index:

PUT /my-index/_settings
{
  "index.mapping.total_fields.limit": 2500
}