Elasticsearch

1. 人民网项目搭建

由于elasticsearch版本多，又有多个Java客户端，首次搭建时，没有明确使用哪个客户端，由此带来许多问题。
客户端发展史：Node client(2.3弃用) —> Transport client(7.0弃用) —>Jest client —> Rest client(low/hign)。前两种使用es原生传输 协议和集群交互，JestClient兼容性优于前两者,不用考虑Es集群使用es版本问题，low REST客户端，通过http与集群交互，用户需自己编组请求JSON串，及解析响应JSON串。兼容所有ES版本。hign REST基于low REST增加了编组请求JSON串、解析响应JSON串等相关api。使用的版本需要保持和ES服务端的版本一致，否则会有版本问题。设置了默认调优参数，若版本匹配，其性能会更加优秀。

最初配置

项目初始化为2.3.12.RELEASE，后来可能误操作修改了spring boot版本

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
            <version>2.6.1</version>
        </dependency>

{
  "name" : "elacticsearch-ess-esn-3-1",
  "cluster_name" : "elacticsearch",
  "cluster_uuid" : "aaVcd-QVToKa7h5HP7NCNw",
  "version" : {
    "number" : "7.9.3",
    "build_flavor" : "oss",
    "build_type" : "tar",
    "build_hash" : "c4138e51121ef06a6404866cddc601906fe5c868",
    "build_date" : "2020-10-16T10:36:16.141335Z",
    "build_snapshot" : false,
    "lucene_version" : "8.6.2",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

出现问题：无论如何配置都无法构建es连接

修改配置

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>

点进data-es可以看到

<dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter</artifactId>
      <version>2.3.2.RELEASE</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework.data</groupId>
      <artifactId>spring-data-elasticsearch</artifactId>
      <version>4.0.2.RELEASE</version>
      <scope>compile</scope>
      <exclusions>
        <exclusion>
          <artifactId>transport</artifactId>
          <groupId>org.elasticsearch.client</groupId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

配置文件，此处ip和端口可修改为通过yml获取

@Component
public class EsClientConfig {//extends AbstractElasticsearchConfiguration
    /*@Override
    @Bean
    public RestHighLevelClient elasticsearchClient() {
        final ClientConfiguration clientConfiguration = ClientConfiguration.builder().connectedTo("139.198.17.162:9200").build();
        return RestClients.create(clientConfiguration).rest();
    }*/
    public static final RequestOptions COMMON_OPTIONS;
    static {
        RequestOptions.Builder builder = RequestOptions.DEFAULT.toBuilder();
        COMMON_OPTIONS = builder.build();
    }
    @Bean
    public RestHighLevelClient esRestClient() {
        RestClientBuilder builder = null;
        // 可以指定多个es
        builder = RestClient.builder(new HttpHost("192.168.0.60", 9200, "http"));
        RestHighLevelClient client = new RestHighLevelClient(builder);
        return client;
    }
}

实体类引入,到此完成

@Qualifier("esRestClient")
@Autowired
private RestHighLevelClient highLevelClient;

2. should must联用导致的should失效问题

1. 工作中使用es查询，本意是想匹配平台id，并且多项商品id匹配一项，原dsl语句

   GET app_openapi_youqian_goodsinfo_*/_search
   {
   "query": {
    "bool": {
      "must": [
        {
          "term": {
            "platform_id": {
              "value": "1001",
              "boost": 1
            }
          }
        }
      ],
      "should": [
        {
          "term": {
            "goods_id.keyword": {
              "value": "646484693204",
              "boost": 1
            }
          }
        }
      ],
      "adjust_pure_negative": true,
      "boost": 1
    }
   }
   }

2. 使用嵌套语法

   {
   "query": {
      "bool": {
         "should": [
            {
               "bool": {
                  "must": [
                     {"term": {"sex": "男"}},
                     {"term": {"score": "70"}}
                  ]
               }
            },
            {
               "bool": {
                  "must": [
                     {"term": {"sex": "男"}},
                     {"term": {"score": "80"}}
                  ]
               }
            }
         ]
      }
   }
   }

   或者

   {
   "query": {
      "bool": {
         "should": [
            {
               "bool": {
                  "must": [
                     {"term": {"sex": "男"}},
                     {"term": {"score": "70"}}
                  ]
               }
            },
            {
               "bool": {
                  "must": [
                     {"term": {"sex": "男"}},
                     {"term": {"score": "80"}}
                  ]
               }
            }
         ]
      }
   }
   }

3. 使用”minimum_should_match”: 1

   GET app_openapi_youqian_goodsinfo_*/_search
   {
   "query": {
    "bool": {
      "must": [
        {
          "term": {
            "platform_id": {
              "value": "1001",
              "boost": 1
            }
          }
        }
      ],
      "should": [
        {
          "term": {
            "goods_id.keyword": {
              "value": "646484693204",
              "boost": 1
            }
          }
        }
      ],
      "minimum_should_match": 1,
      "adjust_pure_negative": true,
      "boost": 1
    }
   }
   }