005 文档API

1.自动创建索引控制

　　Automatic index creation is controlled by the action.auto_create_index setting. This setting defaults to true, meaning that indices are always automatically created. Automatic index creation can be permitted only for indices matching certain patterns by changing the value of this setting to a comma-separated list of these patterns. It can also be explicitly permitted and forbidden by prefixing patterns in the list with a + or -. Finally it can be completely disabled by changing this setting to false.

　　意思是：

　　　　默认是true，会自动创建索引。

　　　　可以配合通配符，决定哪些配置可以被创建，哪些配置不允许被创建

　　　　可以设置false，完全禁止设置

　　测试:

 PUT _cluster/settings
 {
     "persistent": {
         "action.auto_create_index": "twitter,index10,-index1*,+ind*"
     }
 }

 POST ind1/dov/1
 {
   "score":"10"
 }

　　说明：

　　　　Permit only the auto-creation of indices called twitter, index10, no other index matching index1*, and any other index matching ind*. The patterns are matched in the order in which they are given.

　　效果：

 #! Deprecation: [types removal] Specifying types in document index requests is deprecated, use the typeless endpoints instead (/{index}/_doc/{id}, /{index}/_doc, or /{index}/_create/{id}).
 {
   "_index" : "ind1",
   "_type" : "dov",
   "_id" : "1",
   "_version" : 1,
   "result" : "created",
   "_shards" : {
     "total" : 2,
     "successful" : 1,
     "failed" : 0
   },
   "_seq_no" : 0,
   "_primary_term" : 1
 }

　　再执行：

 POST /index11/doc/1
 {
   "score":"10"
 }

　　效果：

#! Deprecation: [types removal] Specifying types in document index requests is deprecated, use the typeless endpoints instead (/{index}/_doc/{id}, /{index}/_doc, or /{index}/_create/{id}).
{
  "error" : {
    "root_cause" : [
      {
        "type" : "index_not_found_exception",
        "reason" : "no such index [index11] and [action.auto_create_index] contains [-index1*] which forbids automatic creation of the index",
        "index_uuid" : "_na_",
        "index" : "index11"
      }
    ],
    "type" : "index_not_found_exception",
    "reason" : "no such index [index11] and [action.auto_create_index] contains [-index1*] which forbids automatic creation of the index",
    "index_uuid" : "_na_",
    "index" : "index11"
  },
  "status" : 404
}

　　再次恢复默认：

 PUT _cluster/settings
 {
     "persistent": {
         "action.auto_create_index": "true"
     }
 }

　　返回：

 {
   "acknowledged" : true,
   "persistent" : {
     "action" : {
       "auto_create_index" : "true"
     }
   },
   "transient" : { }
 }

2.版本控制

　　ES提供了版本控制，可以通过使用版本查询参数来指定文档的特定版本。

　　内部的版本控制是默认版本，从1开始，每次更新递增，包括删除。版本号可以在外部设置，不过要启用此功能，需要将version_type设置为外部。

　　版本控制是一个实时的过程，不受实时搜索操作的影响。

　　修改过下面的信息：

 PUT index1/_doc/1
 {
   "name":"tom1",
   "sex":"M"
 }

　　查看：

 GET index1/_doc/1

　　返回：

 {
   "_index" : "index1",
   "_type" : "_doc",
   "_id" : "1",
   "_version" : 2,
   "_seq_no" : 1,
   "_primary_term" : 3,
   "found" : true,
   "_source" : {
     "name" : "tom1",
     "sex" : "M"
   }
 }

　　发现上面是version为2，所以，可以使用version进行过滤：

 GET index1/_doc/1?version=2

　　效果与上面的执行结果相同。

　　关于版本version_type的功能，后续明白了再补充。

4.操作类型

　　The index operation also accepts an op_type that can be used to force a create operation, allowing for "put-if-absent" behavior. When create is used, the index operation will fail if a document by that id already exists in the index.

　　意思是：用于强制创建操作，如果存在，则操作失败，避免覆盖现有的文档.

　　我的理解是，不会再允许创建了，version不会进行叠加了，只会报错。但是如果再去掉，马上又可以进行更新掉，version进行叠加。

 GET /_cat/indices
 DELETE /twitter/
 PUT twitter/_doc/1?op_type=create
 {
     "user" : "kimchy",
     "post_date" : "2009-11-15T14:12:12",
     "message" : "trying out Elasticsearch"
 }

　　一次创建：

 {
   "_index" : "twitter",
   "_type" : "_doc",
   "_id" : "1",
   "_version" : 1,
   "result" : "created",
   "_shards" : {
     "total" : 2,
     "successful" : 1,
     "failed" : 0
   },
   "_seq_no" : 0,
   "_primary_term" : 1
 }

　　再次创建：

 {
   "error": {
     "root_cause": [
       {
         "type": "version_conflict_engine_exception",
         "reason": "[1]: version conflict, document already exists (current version [1])",
         "index_uuid": "Cp1z9uTRRhG0wIV2XiJPpQ",
         "shard": "0",
         "index": "twitter"
       }
     ],
     "type": "version_conflict_engine_exception",
     "reason": "[1]: version conflict, document already exists (current version [1])",
     "index_uuid": "Cp1z9uTRRhG0wIV2XiJPpQ",
     "shard": "0",
     "index": "twitter"
   },
   "status": 409
 }

5.自动生成ID

　　The index operation can be executed without specifying the id. In such a case, an id will be generated automatically. In addition, the op_type will automatically be set to create. Here is an example (note the POST used instead of PUT)

 ID自动生成
 POST twitter/_doc/
 {
     "user" : "kimchy",
     "post_date" : "2009-11-15T14:12:12",
     "message" : "trying out Elasticsearch"
 }

　　结果：

 {
   "_index" : "twitter",
   "_type" : "_doc",
   "_id" : "cI7jS2wBE-J5sxKYhB25",
   "_version" : 1,
   "result" : "created",
   "_shards" : {
     "total" : 2,
     "successful" : 1,
     "failed" : 0
   },
   "_seq_no" : 50,
   "_primary_term" : 1
 }

　　说明：POST这种多次提交，id在一直变化，但是version不会变化。

　　　　　但是PUT，id不会变化，version一直在变。