document数据格式（类似mongoDb）

面向文档的搜索分析引擎

（1）应用系统的数据结构都是面向对象的，复杂的
（2）对象数据存储到数据库中，只能拆解开来，变为扁平的多张表，每次查询的时候还得还原回对象格式，相当麻烦
（3）ES是面向文档的，文档中存储的数据结构，与面向对象的数据结构是一样的，基于这种文档数据结构，es可以提供复杂的索引，全文检索，分析聚合等功能
（4）es的document用json数据格式来表达

快速检查集群的健康状况

es提供了一套api，叫做cat api，可以查看es中各种各样的数据

GET /_cat/health

不加v参数不带头看不出来

GET /_cat/health?v

epoch      timestamp cluster       status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
1488006741 15:12:21  elasticsearch yellow          1         1      1   1    0    0        1             0                  -                 50.0%

如何快速了解集群的健康状况？green、yellow、red？

green：每个索引的primary shard和replica shard都是active状态的
yellow：每个索引的primary shard都是active状态的，但是部分replica shard不是active状态，处于不可用的状态
red：不是所有索引的primary shard都是active状态的，部分索引有数据丢失了

为什么现在会处于一个yellow状态？

从新解压一个.zip并启动

再次运行_cat/health?v

epoch      timestamp cluster       status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
1530454164 22:09:24  elasticsearch green           2         2      2   1    0    0        0             0                  -                100.0%

健康状态是绿色

也可以运行_cluster/health

快速查看集群中有哪些索引?

GET _cat/indices?v

health status index   uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   .kibana mTtWngicSOG4Ys8y7YIdeg   1   1          1            0      3.1kb          3.1kb

简单的索引操作

创建索引：PUT /test_index?pretty

返回结果

{
  "acknowledged": true,
  "shards_acknowledged": true,
  "index": "test_index"
}

GET _cat/indices?v

health status index      uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   test_index XmS9DTAtSkSZSwWhhGEKkQ   5   1          0            0       650b           650b
yellow open   .kibana    rUm9n9wMRQCCrRDEhqneBg   1   1          1            0      3.1kb          3.1kb

删除索引：DELETE /test_index?pretty

health status index   uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   .kibana rUm9n9wMRQCCrRDEhqneBg   1   1          1            0      3.1kb          3.1kb

数据的CRUD操作

1、新增商品：新增文档，建立索引

语法：
PUT /index/type/id
{
"json数据"
}

执行

PUT /ecommerce/product/1
{
    "name" : "gaolujie yagao",
    "desc" :  "gaoxiao meibai",
    "price" :  30,
    "producer" :      "gaolujie producer",
    "tags": [ "meibai", "fangzhu" ]
}

返回结果：

{
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "_version": 1,  //版本号
  "result": "created",
  "_shards": {
    "total": 2, //要写入的shards数   replica没有写入、因为是一个节点、replica和primarykey
    "successful": 1,//写入成功几个
    "failed": 0
  },
  "created": true //写入成功状态
}

es会自动建立index和type，不需要提前创建，而且es默认会对document每个field都建立倒排索引，让其可以被搜索

2、查询商品：检索文档

语法：GET /index/type/id

执行：GET /ecommerce/product/1

{
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "_version": 1,
  "found": true,
  "_source": {
    "name": "gaolujie yagao",
    "desc": "gaoxiao meibai",
    "price": 30,
    "producer": "gaolujie producer",
    "tags": [
      "meibai",
      "fangzhu"
    ]
  }
}

3、修改商品：替换文档

执行、必须把所有参数带上（不好）

PUT /ecommerce/product/1
{
    "name" : "jiaqiangban gaolujie yagao",
    "desc" :  "gaoxiao meibai",
    "price" :  30,
    "producer" :      "gaolujie producer",
    "tags": [ "meibai", "fangzhu" ]
}

结果：

{
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "_version": 2,  //版本号变了
  "result": "updated",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "created": false
}

如果不全部带上、那么就会直接被覆盖、执行

PUT /ecommerce/product/1
{
    "name" : "jiaqiangban gaolujie yagao"
}

在执行GET /ecommerce/product/1

结果

{
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "_version": 3,
  "found": true,
  "_source": {
    "name": "jiaqiangban gaolujie yagao"
  }
}

4、修改商品：更新文档

POST /ecommerce/product/1/_update
{
  "doc": {
    "name": "jiaqiangban gaolujie yagao"
  }
}

结果

{
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "_version": 5,
  "found": true,
  "_source": {
    "name": "jiaqiangban gaolujie yagao",
    "desc": "gaoxiao meibai",
    "price": 30,
    "producer": "gaolujie producer",
    "tags": [
      "meibai",
      "fangzhu"
    ]
  }
}

5、删除商品：删除文档

语法：DELETE /ecommerce/product/1

{
  "found": true,
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "_version": 9,
  "result": "deleted",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  }
}

在执行GEI操作结果数据没

{
  "_index": "ecommerce",
  "_type": "product",
  "_id": "1",
  "found": false
}