笔记：remote reindex无法从ES7--＞ES6

背景

测试经常使用reindex API，一般都是同版本或者升级版本使用；

使用

remote reindex

POST _reindex
{
  "conflicts": "proceed",
  "source": {
    "remote": {
      "host": "http://xxx.com:80",
      "username": "elastic",
      "password": "xxxxx",
      "headers": {
        "x-client-app": "12345"
      }
    },
    "index": "test",
    "size": 1000,
    "query": {
      "match_all": {}
    }
  },
  "dest": {
    "index": "test"
  }
}

发现报错

{
  "error": {
    "root_cause": [
      {
        "type": "exception",
        "reason": "Error parsing the response, remote is likely not an Elasticsearch instance"
      }
    ],
    "type": "exception",
    "reason": "Error parsing the response, remote is likely not an Elasticsearch instance",
    "caused_by": {
      "type": "x_content_parse_exception",
      "reason": "[1:242] [search_response] failed to parse field [hits]",
      "caused_by": {
        "type": "x_content_parse_exception",
        "reason": "[1:242] [hits] total doesn't support values of type: START_OBJECT"
      }
    }
  },
  "status": 500
}

原因：remote reindex无法从ES7同步数据到ES6（不能降级）