修改ES索引Mapping

修改ES索引Mapping

背景：

之前的有一個字段設置是keyword，然而，由於業務場景的調整，現在改成text，模糊檢索，爲了需求變更，需要進行修改ES Mapping

操作步驟

1. 創建新的索引

   POST new_index/_mapping
   {
     "properties": {
       "id": {
         "type": "keyword"
       },
       "filed_name": {
         "type": "text",
         "analyzer": "standard",
         "search_analyzer": "standard",
         "fields": {
           "keyword": {
             "type": "keyword",
             "ignore_above": 256
           }
         }
       }
     }
   }
   

2. 將新索引的別名設置爲業務需要的別名

   POST/PUT都可以，ES新創建的索引默認是不可寫入的，需要加入is_write_index爲true的設定

   POST _aliases
   {
     "actions": [
       {
         "add": {
           "index": "new_index",
           "alias": "business_index"
            ,"is_write_index": true
         }
       }
     ]
   }
   

不進行設置寫入設置，會有異常如下

no write index is defined for alias [o2o-nearby-service_brand_merchant]. The write index may be explicitly disabled using is_write_index=false or the alias points to multiple indices without one being designated as a write index

3. 從指定index上面拷貝數據

   POST _reindex
   {
     "source": {
       "index": "old_index"
     },
     "dest": {
       "index": "new_index"
     }
   }
   

4. 驗證是否數據是否拷貝成功

   # 數據數量驗證
   GET old_index/_count
   GET new_index/_count
   # 數據詳細比對驗證
   GET old_index/_search
   GET new_index/_search
   

   如果驗證有問題，重複步驟3，如果線上場景複雜，建議不要使用該方式操作，更建議使用API文檔使用查詢後，_bluk批量的方式，用代碼實現數據遷移到新索引

5. 移除舊索引的業務映射

   POST _aliases
   {
     "actions": [
       {
         "remove": {
           "index": "old_index",
           "alias": "business_index"
         }
       }
     ]
   }