Elasticsearch 如何实现索引的伪·命名空间

环境说明

jdk8
elasticsearch7.4.0
springboot 2.3.12.RELEASE
spring-data-elasticsearch 4.0.9.RELEASE

注：本文不做特殊说明的情况下，client1与client2使用相同配置

应用场景

在公司内部资源紧张的情况下，多个项目使用同一个elasticsearch并且数据互不干扰，实现资源的最大化利用，节约成本

集成Elasticsearch

pom（client1与client2相同）

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.12.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-elasticsearch</artifactId>
            <version>4.0.9.RELEASE</version>
        </dependency>
    </dependencies>

config（client1与client2相同）

@Configuration
public class RestClientConfig extends AbstractElasticsearchConfiguration {
    @Bean
    @Override
    public RestHighLevelClient elasticsearchClient() {
        final ClientConfiguration clientConfiguration = ClientConfiguration.builder()
                .connectedTo("localhost:9200")
                .build();

        return RestClients.create(clientConfiguration).rest();
    }
}

yml

client1

spring.data.elasticsearch.client.namespace=client1
server.port=8081

client2

spring.data.elasticsearch.client.namespace=client2
server.port=8082

索引名定义(client1与client2相同)

定义变量获取

@Configuration
public class EsConst {
    @Value("${spring.data.elasticsearch.client.namespace}")
    private String elasticsearchNamespace;
    @Bean
    public String getElasticsearchNamespace(){
        return elasticsearchNamespace;
    }
}

新建User 实体类，指定索引名称为namespace.user

@Document(indexName = "#{@getElasticsearchNamespace}.user")
public class User {
    @Field(type = FieldType.Text)
    private String id;
    @Field(type = FieldType.Text)
    private String name;
    @Field(type = FieldType.Text)
    private String phone;
    @Field(type = FieldType.Text)
    private String namespace;

// 省略get/set ......
}

增加测试方法findAll与save

client1

Dao

@Repository
public interface UserDao extends CrudRepository<User,String> {
}

Service

@Service
public class TestService {
    @Autowired
    private UserDao userDao;
    public void findAll(){
        Iterable<User> all = userDao.findAll();

        Iterator<User> iterator = userDao.findAll().iterator();
        User next1 = iterator.next();

        System.out.println(next1.toString());
    }
    public void save(){
        User user = new User();
        user.setId("1");
        user.setName("client1");
        user.setNamespace("elasticsearch:client1");
        user.setPhone("111");
        User save = userDao.save(user);
        System.out.println(save.toString());
    }
}

Test

@RunWith(SpringRunner.class)
@SpringBootTest
public class ClientApplicationTests {
    @Autowired
    private TestService testService;
    @Test
    public void findAll(){
        testService.findAll();
    }
    @Test
    public void save(){
        testService.save();
    }
}

client2

Dao

@Repository
public interface UserDao extends CrudRepository<User,String> {
}

Service

@Service
public class TestService {
    @Autowired
    private UserDao userDao;
    public void findAll(){
        Iterable<User> all = userDao.findAll();

        Iterator<User> iterator = userDao.findAll().iterator();
        User next1 = iterator.next();

        System.out.println(next1.toString());
    }
    public void save(){
        User user = new User();
        user.setId("2");
        user.setName("client2");
        user.setNamespace("elasticsearch:client2");
        user.setPhone("222");
        User save = userDao.save(user);
        System.out.println(save.toString());
    }
}

Test

@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoApplicationTests {
	@Autowired
	private TestService testService;
	@Test
	public void findAll(){
		testService.findAll();
	}
	@Test
	public void save(){
		testService.save();
	}
}

测试验证

预期结果
- 生成client1.user与client2.user索引
- 访问8081返回client1用户信息，访问8082返回client2用户信息
实际结果

image-20220408212339570

总结

我们通过增加一个配置类来获取自定义的namespace,然后在类指定索引名时通过获取变量的形式去读取，这样生成的索引就会带一个前缀，也就是我们想要的namespace·，也就实现了我们最初的目标，复用同一个elasticsearch,达到节省服务器资源的目的

源码地址

https://github.com/TianPuJun/es-demo
https://download.csdn.net/download/C1041067258/85096340

参考链接

SpringDataElasticsearch