PUT

文档是不可改变的，不能修改他们。
如果想要更新现在有的文档，需要重建索引或者进行替换
不能访问旧版本的文档，但它不是立即删除的

PUT /website/blog/123
{
  "title": "My first blog entry",
  "text":  "I am starting to get the hang of this...",
  "date":  "2014/01/02"
}

返回的结果：_version自增，created，表示不是create

{
  "_index" :   "website",
  "_type" :    "blog",
  "_id" :      "123",
  "_version" : 2,
  "created":   false
}

可以利用_version来保证安全

put请求，（1）是指_version在1的时候才能更新

PUT /website/blog/1?version=1 (1)
{
  "title": "My first blog entry",
  "text":  "Starting to get the hang of this..."
}

更新成功

{
  "_index":   "website",
  "_type":    "blog",
  "_id":      "1",
  "_version": 2
  "created":  false
}

再次相同请求，则```490 Conflict

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

外部系统保证安全

指定版本号需要大于ES当前版本号
创建外部版本号为5的博客

PUT /website/blog/2?version=5&version_type=external
{
  "title": "My first external blog entry",
  "text":  "Starting to get the hang of this..."
}

成功响应：

{
  "_index":   "website",
  "_type":    "blog",
  "_id":      "2",
  "_version": 5,
  "created":  true
}

更新这个文档，指定新版本号

PUT /website/blog/2?version=10&version_type=external
{
  "title": "My first external blog entry",
  "text":  "This is a piece of cake..."
}

成功，失败则返回之前的冲突错误

{
  "_index":   "website",
  "_type":    "blog",
  "_id":      "2",
  "_version": 10,
  "created":  false
}