OpenSearch/rest-api-spec/api/indices.get_upgrade.json

{
  "indices.get_upgrade": {
    "documentation": "http://www.elastic.co/guide/en/elasticsearch/reference/master/indices-upgrade.html",
    "methods": ["GET"],
    "url": {
      "path": "/_upgrade",
      "paths": ["/_upgrade", "/{index}/_upgrade"],
      "parts": {
        "index": {
          "type" : "list",
          "description" : "A comma-separated list of index names; use `_all` or empty string to perform the operation on all indices"
        }
      },
      "params": {
        "ignore_unavailable": {
            "type" : "boolean",
            "description" : "Whether specified concrete indices should be ignored when unavailable (missing or closed)"
        },
        "allow_no_indices": {
            "type" : "boolean",
            "description" : "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
        },
        "expand_wildcards": {
            "type" : "enum",
            "options" : ["open","closed","none","all"],
            "default" : "open",
            "description" : "Whether to expand wildcard expression to concrete indices that are open, closed or both."
        },
        "human": {
            "type": "boolean",
            "description": "Whether to return time and byte values in human-readable format.",
            "default": false
        }
      }
    },
    "body": null
  }
}