ElasticSearch改造研报查询实践

背景：

　　1，系统简介：通过人工解读研报然后获取并录入研报分类及摘要等信息，系统通过摘要等信息来获得该研报的URI

　　2，现有实现：老系统使用MSSQL存储摘要等信息，并将不同的关键字分解为不同字段来提供搜索查询

　　3，存在问题：

　　　　-查询操作繁琐,死板：例如要查某个机构，标题含有周报的研报，现有系统需要勾选相应字段再输入条件

　　　　-查询速度缓慢，近千万级别数据响应时间4-5s

　　4，改进：使用es优化，添加多个关键字模糊查询(非长文本数据，因此未使用_socre进行评分查询)

　　　　-例如：输入“国泰君安 周报”就可查询到所有相关的国泰君安的周报

1，新建Index

curl -X PUT 'localhost:9200/src_test_1' -H 'Content-Type: application/json' -d '
{
    "settings": {
        "number_of_shards": 1,
        "number_of_replicas":
    },
  "mappings": {
    "doc_test": {
      "properties": {
        "title": {#研报综合标题
          "type": "text",
          "analyzer": "ik_max_word",
          "search_analyzer": "ik_max_word"
        },
        "author": {#作者
          "type": "text",
          "analyzer": "ik_max_word",
          "search_analyzer": "ik_max_word"
        },
        "institution": {#机构
            "type": "text",
            "analyzer": "ik_max_word",
            "search_analyzer": "ik_max_word"
        },
          "industry": {#行业
              "type": "text",
              "analyzer": "ik_max_word",
              "search_analyzer": "ik_max_word"
          },
          "grade": {#评级
              "type": "text",
              "analyzer": "ik_max_word",
              "search_analyzer": "ik_max_word"
          },
          "doc_type": {#研报分类
              "type": "text",
              "analyzer": "ik_max_word",
              "search_analyzer": "ik_max_word"
          },
         "time": {#发布时间
          "type": "date" ,
          "format": "yyyy-MM-dd HH:mm:ss||yyyy-MM-dd||epoch_millis"
         },
          "doc_uri": {#地址
           "type": "text",
            "index":false
         },
          "doc_size": {#文件大小
           "type": "integer",
            "index":false
         },
          "market": {#市场
          "type": "byte"
         }
      }
    }
  }
}'

※特别提示对于需要模糊查询的中文文本字段最好都设置text属性(keyword无法被分词：用于精确查找)，并使用ik_max_word分词器。

※使用ik_max_word原因：针对该场景，例如我想使用“国泰”关键词进行匹配，如果使用默认ik会将“国”，“泰”分开进行查询，而不是需求的“国泰”这个词

2，数据导入(CSV分批)

import pandas as pd
import numpy as np
from elasticsearch import Elasticsearch
from elasticsearch.helpers import bulk
es = Elasticsearch()

data_will_insert = []
x = 1

# #使用pandas读取csv数据；如果出现乱码加：encoding = "ISO-8859-1"
src_data = pd.read_csv('ResearchReportEx.csv')

for index,i in src_data.iterrows():
    x+=1
    #每次插入100000条
    if x%100000 == 99999:
        #es批量插入
        success, _ = bulk(es, data_will_insert, index='src_test_1', raise_on_error=True)
        print('Performed %d actions' % success)
        data_will_insert = []

    #判断市场
    if i['ExchangeType'] == 'CN':
        market = 0
    elif i['ExchangeType'] == 'HK':
        market = 1
    elif i['ExchangeType'] == 'World':
        market = 2
    else:
        market = 99

    data_will_insert.append({"_index":'src_test_1',"_type": 'doc_test','_source':
                {
                'title':i['Title'],
                'author':i['AuthorName'],
                'time':i['CreateTime']+':00',
                'institution':i['InstituteNameCN'],
                'doc_type':i['KindName'] if i['Kind2Name'] is np.NaN else i['KindName']+'|%s' % i['Kind2Name'],
                'industry':'' if i['IndustryName'] is np.NaN else i['IndustryName'],
                'grade':'' if i['GradeName'] is np.NaN else i['GradeName'],
                'doc_uri':i['FileURL'],
                'doc_size':i['Size'],
                'market':market
                }
                })

#将最后剩余在list中的数据插入
if len(data_will_insert)>0:
    success, _ = bulk(es, data_will_insert, index='src_test_1', raise_on_error=True)
    print('Performed %d actions' % success)

3，查询

import time
from elasticsearch import Elasticsearch
from elasticsearch.helpers import scan

# es连接
es = Elasticsearch()

# 计算运行时间装饰器
def cal_run_time(func):
    def wrapper(*args, **kwargs):
        start_time = time.time()
        res = func(*args, **kwargs)
        end_time = time.time()
        print(str(func) + '---run time--- %s' % str(end_time - start_time))
        return res

    return wrapper

@cal_run_time
def query_in_es():
    body = {
        "query": {
            "bool": {
                "must": [
                    {
                        "multi_match": {
                            "query": "国泰 报告",
                            "type": "cross_fields",#跨字段匹配
                            "fields": ["title", "institution","grade"
                                       "doc_type","author","industry"],#在这6个字段中进行查找
                            "operator": "and"
                        }#此查询条件等于：query中的关键词都在fields中所有字段拼接成的字符中
                    },
                    {
                        "range": {
                            "time": {
                                "gte": '2018-02-01'#默认查询限制时间
                            }
                        }
                    }
                ],
            }
        }
    }

    # 根据body条件查询
    scanResp = scan(es, body, scroll="10m", index="src_test_1", doc_type="doc_test", timeout="10m")
    row_num = 0

    for resp in scanResp:
        print(resp['_source'])
        row_num += 1

    print(row_num)

query_in_es()

※测试结果速度相当快：多关键字查询只需零点几秒