Elasticsearch 版本控制

内部版本控制：_version自增长，修改数据后，_version会自动加1

外部版本控制：为了保持_version与外部版本控制的数值一致
			      使用version_type=external
			      检查数据当前的version值是否小于请求中的version值

				  
PUT /library/books/1
{
  "title": "Elasticsearch: The Definitive Guide",
  "name" : {
    "first" : "Zachary",
    "last" : "Tong"

  },
  "publish_date":"2015-02-06",
  "price":"59.99"

}


查看数据:

GET /library/books/1

{
  "_index": "library",
  "_type": "books",
  "_id": "1",
  "_version": 1,
  "found": true,
  "_source": {
    "title": "Elasticsearch: The Definitive Guide",
    "name": {
      "first": "Zachary",
      "last": "Tong"
    },
    "publish_date": "2015-02-06",
    "price": "59.99"
  }
}

修改数据:

POST /library/books/1/_update
{
  "doc": {
     "price" : 10
  }
}

此时版本为2：

{
  "_index": "library",
  "_type": "books",
  "_id": "1",
  "_version": 2,
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  }
}

指定版本去更新:
POST /library/books/1/_update?version=3
{
  "doc": {
     "price" : 15
  }
}


{
   "error": {
      "root_cause": [
         {
            "type": "version_conflict_engine_exception",
            "reason": "[books][1]: version conflict, current [2], provided [3]",
            "shard": "3",
            "index": "library"
         }
      ],
      "type": "version_conflict_engine_exception",
      "reason": "[books][1]: version conflict, current [2], provided [3]",
      "shard": "3",
      "index": "library"
   },
   "status": 409
}