elasticsearch 索引，更新，增量更新，不停机修改升级 ,简单使用

举例： 根据商品名称搜索商品

1. 创建索引 product_v1 为什么要带v1呢，后面方便升级

   #新增索引
   put product_v1?pretty
   
   #查看一下
   get _cat/indices?v
   

2. 定义map,简单设置，只定义id与name,还有updatetime

   #设置map
   POST product_v1/_mapping/doc
   {
     "properties": {
       "name":{
           "type": "text",
           "analyzer": "ik_max_word",
           "search_analyzer": "ik_max_word"
       },
       "id":{
           "type": "long"
       },
       "updatetime": {
           "type": "date",
           "format": "yyyy-MM-dd HH:mm:ss"
       }
     }
   }
   #查看map
   GET /product_v1/_mapping/
   
   

3. 添加别名，将product_v1设置为product,后面就可以针对别名操作。设置别名最大的好处，是后期变更map时很方便，开发时连接product即可

   POST /_aliases
   {
       "actions" : [
           { "add" : { "index" : "product_v1",  "alias" : "product" } }
       ]
   }
   
   

4. 添加一些索引随便添加，日期就不写了

   PUT product/doc/1?pretty
   {
    "name":"网络红外半球摄像机"
   }
   
   PUT product/doc/2?pretty
   {
    "name":"网络高清硬盘录像机"
   }
   
   PUT product/doc/3?pretty
   {
    "name":"网络红外高清中速球机"
   }
   
   

5. 搜索测试数据

   GET  product/_search
   {
       "query": {
       "match": {
         "name": "网络"
       }
     }
   }
   
   

6. 升级变更map, 比如name变更为productName。 添加新字段typeName

   #1.建立新索引
   put product_v2?pretty
   
   #2.设置新map
   POST product_v2/_mapping/doc
   {
     "properties": {
       "productName":{
           "type": "text",
           "analyzer": "ik_max_word",
           "search_analyzer": "ik_max_word"
       },
       "typeName":{
           "type": "text",
           "analyzer": "ik_max_word",
           "search_analyzer": "ik_max_word"
       }
       ...
       ...
     }
   }
       
   #3.得新添加索引到`product_v2`,
   PUT product_v2/doc/1?pretty
   {
    "productName":"网络红外半球摄像机",
     ...
     ...
   }
   
   #4.设置别名指向新索引，原索引自己决定是否删除
   POST /_aliases
   {
       "actions" : [
           { "add" : { "index" : "product_v2",  "alias" : "product" } }
       ]
   }
   
   #或者同时删除掉原索引
   POST /_aliases
   {
       "actions" : [
           { "remove" : { "index" : "product_v1",  "alias" : "product" } },
           { "add" : { "index" : "product_v2",  "alias" : "product" } }
       ]
   }
   #或者单独删除都可以
   
   DELETE   product_v1
       
   

7. 升级变更map, 比如字段类型需要变更，如给typeName添加一个keyword的类型

   #1.新建索引
   put product_v3?pretty
   #2.设置新`map`
   POST product_v3/_mapping/doc
   {
     "properties": {
       "typeName":{
           "type": "text",
           "analyzer": "ik_max_word",
           "search_analyzer": "ik_max_word",
           "fields": {
               "keyword": {
                   "type": "keyword"
               }
           }
       }
       ...
       ...
     }
   }
   
   #3.使用`reindex`得做索引
   post _reindex
   {
     "source": {
       "index": "product"
     },
     "dest": {
       "index": "product_v2"
     }
   }
   
   #4.将别名切到新索引,同上
   POST /_aliases
   {
       "actions" : [
           { "add" : { "index" : "product_v2",  "alias" : "product" } }
       ]
   }
   ...