1. document數據格式

面向文檔的搜索分析引擎

（1）應用系統的數據結構都是面向對象的，復雜的
（2）對象數據存儲到數據庫中，只能拆解開來，變為扁平的多張表，每次查詢的時候還得還原回對象格式，相當麻煩
（3）ES是面向文檔的，文檔中存儲的數據結構，與面向對象的數據結構是一樣的，基于這種文檔數據結構，es可以提供復雜的索引，全文檢索，分析聚合等功能
（4）es的document用json數據格式來表達

1 public class Employee { 2 3 private String email; 4 private String firstName; 5 private String lastName; 6 private EmployeeInfo info; 7 private Date joinDate; 8 9 } 10 11 private class EmployeeInfo { 12 13 private String bio; // 性格 14 private Integer age; 15 private String[] interests; // 興趣愛好 16 17 } 18 19 EmployeeInfo info = new EmployeeInfo(); 20 info.setBio("curious and modest"); 21 info.setAge(30); 22 info.setInterests(new String[]{"bike", "climb"}); 23 24 Employee employee = new Employee(); 25 employee.setEmail("zhangsan@sina.com"); 26 employee.setFirstName("san"); 27 employee.setLastName("zhang"); 28 employee.setInfo(info); 29 employee.setJoinDate(new Date()); 30 31 employee對象：里面包含了Employee類自己的屬性，還有一個EmployeeInfo對象

兩張表：employee表，employee_info表，將employee對象的數據重新拆開來，變成Employee數據和EmployeeInfo數據
employee表：email，first_name，last_name，join_date，4個字段
employee_info表：bio，age，interests，3個字段；此外還有一個外鍵字段，比如employee_id，關聯著employee表

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{"email": "zhangsan@sina.com","first_name": "san","last_name": "zhang","info": {"bio": "curious and modest","age": 30,"interests": [ "bike", "climb" ]},"join_date": "2017/01/01" }

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我們就明白了es的document數據格式和數據庫的關系型數據格式的區別

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2. 電商網站商品管理案例

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有一個電商網站，需要為其基于ES構建一個后臺系統，提供以下功能：

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（1）對商品信息進行CRUD（增刪改查）操作
（2）執行簡單的結構化查詢
（3）可以執行簡單的全文檢索，以及復雜的phrase（短語）檢索
（4）對于全文檢索的結果，可以進行高亮顯示
（5）對數據進行簡單的聚合分析

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3. 簡單的集群管理

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（1）快速檢查集群的健康狀況

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es提供了一套api，叫做cat api，可以查看es中各種各樣的數據

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GET /_cat/health?vepoch 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%epoch timestamp cluster status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent 1488007113 15:18:33 elasticsearch green 2 2 2 1 0 0 0 0 - 100.0%epoch timestamp cluster status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent 1488007216 15:20:16 elasticsearch yellow 1 1 1 1 0 0 1 0 - 50.0%

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如何快速了解集群的健康狀況？green、yellow、red？

　　green：每個索引的primary shard和replica shard都是active狀態的
　　yellow：每個索引的primary shard都是active狀態的，但是部分replica shard不是active狀態，處于不可用的狀態
　　red：不是所有索引的primary shard都是active狀態的，部分索引有數據丟失了

為什么現在會處于一個yellow狀態？

　　我們現在就一個筆記本電腦，就啟動了一個es進程，相當于就只有一個node。現在es中有一個index，就是kibana自己內置建立的index。由于默認的配置是給每個index分配5個primary shard和5個replica shard，而且primary shard和replica shard不能在同一臺機器上（為了容錯）。現在kibana自己建立的index是1個primary shard和1個replica shard。當前就一個node，所以只有1個primary shard被分配了和啟動了，但是一個replica shard沒有第二臺機器去啟動。做一個小實驗：此時只要啟動第二個es進程，就會在es集群中有2個node，然后那1個replica shard就會自動分配過去，然后cluster status就會變成green狀態。

（2）快速查看集群中有哪些索引

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GET /_cat/indices?vhealth 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

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（3）簡單的索引操作

創建索引：PUT /test_index?prettyhealth 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
刪除索引：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

4. 商品的CRUD操作

（1）新增商品：新增文檔，建立索引

PUT /index/type/id {"json數據" }PUT /ecommerce/product/1 {"name" : "gaolujie yagao","desc" : "gaoxiao meibai","price" : 30,"producer" : "gaolujie producer","tags": [ "meibai", "fangzhu" ] }{"_index": "ecommerce","_type": "product","_id": "1","_version": 1,"result": "created","_shards": {"total": 2,"successful": 1,"failed": 0},"created": true }PUT /ecommerce/product/2 {"name" : "jiajieshi yagao","desc" : "youxiao fangzhu","price" : 25,"producer" : "jiajieshi producer","tags": [ "fangzhu" ] }PUT /ecommerce/product/3 {"name" : "zhonghua yagao","desc" : "caoben zhiwu","price" : 40,"producer" : "zhonghua producer","tags": [ "qingxin" ] }

es會自動建立index和type，不需要提前創建，而且es默認會對document每個field都建立倒排索引，讓其可以被搜索

（2）查詢商品：檢索文檔

GET /index/type/id 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：替換文檔

PUT /ecommerce/product/1 {"name" : "jiaqiangban gaolujie yagao","desc" : "gaoxiao meibai","price" : 30,"producer" : "gaolujie producer","tags": [ "meibai", "fangzhu" ] }{"_index": "ecommerce","_type": "product","_id": "1","_version": 1,"result": "created","_shards": {"total": 2,"successful": 1,"failed": 0},"created": true }{"_index": "ecommerce","_type": "product","_id": "1","_version": 2,"result": "updated","_shards": {"total": 2,"successful": 1,"failed": 0},"created": false }PUT /ecommerce/product/1 {"name" : "jiaqiangban gaolujie yagao" }

替換方式有一個不好，即使必須帶上所有的field，才能去進行信息的修改

（4）修改商品：更新文檔

POST /ecommerce/product/1/_update {"doc": {"name": "jiaqiangban gaolujie yagao"} }{"_index": "ecommerce","_type": "product","_id": "1","_version": 8,"result": "updated","_shards": {"total": 2,"successful": 1,"failed": 0} }

（5）刪除商品：刪除文檔

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

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轉載于:https://www.cnblogs.com/sunfie/p/7016697.html

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