如何在Spring Boot项目中配置多个Elasticsearch连接并实现索引隔离？

直接复制配置类无法生效的原因 #

直接复制原配置类替换参数无法正常运行，Spring启动时会检测到两个同类型同名称的RestHighLevelClient Bean，抛出Bean定义冲突异常。

1. 定义两个独立的ES客户端Bean #

首先编写多ES配置类，给两个实例的Bean设置不同的名称，避免冲突：

@Configuration
public class EsMultiClientConfig {
    // 第一台ES实例客户端
    @Bean("esClientServer1")
    public RestHighLevelClient esClientServer1() {
        CredentialsProvider cp = new BasicCredentialsProvider();
        cp.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("server1用户名", "server1密码"));
        return new RestHighLevelClient(RestClient.builder(new HttpHost("server1地址", server1端口, "https"))
                .setHttpClientConfigCallback(httpAsyncClientBuilder -> httpAsyncClientBuilder.setDefaultCredentialsProvider(cp)
                        .setKeepAliveStrategy(new DefaultConnectionKeepAliveStrategy())));
    }

    // 第二台ES实例客户端
    @Bean("esClientServer2")
    public RestHighLevelClient esClientServer2() {
        CredentialsProvider cp = new BasicCredentialsProvider();
        cp.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("server2用户名", "server2密码"));
        return new RestHighLevelClient(RestClient.builder(new HttpHost("server2地址", server2端口, "https"))
                .setHttpClientConfigCallback(httpAsyncClientBuilder -> httpAsyncClientBuilder.setDefaultCredentialsProvider(cp)
                        .setKeepAliveStrategy(new DefaultConnectionKeepAliveStrategy())));
    }
}

2. 实现索引按实例隔离 #

你要求的entity1存server1、entity2存server2的需求完全可以实现，按Repository包路径拆分绑定对应客户端即可：

• 新建两个Repository包：com.yourproject.repository.es1（存放server1对应的实体操作类）、com.yourproject.repository.es2（存放server2对应的实体操作类）
• 分别编写两个Repository配置类，绑定不同包和对应ES客户端：

server1对应Repository配置 #

@Configuration
@EnableElasticsearchRepositories(
        basePackages = "com.yourproject.repository.es1",
        elasticsearchTemplateRef = "esTemplateServer1"
)
public class Es1RepositoryConfig {
    @Bean
    public ElasticsearchOperations esTemplateServer1(@Qualifier("esClientServer1") RestHighLevelClient esClientServer1) {
        return new ElasticsearchRestTemplate(esClientServer1);
    }
}

server2对应Repository配置 #

@Configuration
@EnableElasticsearchRepositories(
        basePackages = "com.yourproject.repository.es2",
        elasticsearchTemplateRef = "esTemplateServer2"
)
public class Es2RepositoryConfig {
    @Bean
    public ElasticsearchOperations esTemplateServer2(@Qualifier("esClientServer2") RestHighLevelClient esClientServer2) {
        return new ElasticsearchRestTemplate(esClientServer2);
    }
}

后续将entity1对应的Repository放在es1包下，entity2对应的Repository放在es2包下，操作时会自动路由到对应ES实例，自动实现索引隔离。如果不用Spring Data ES的Repository，直接注入客户端时加@Qualifier指定Bean名称即可：

// 注入server1客户端操作entity1
@Autowired
@Qualifier("esClientServer1")
private RestHighLevelClient esClientServer1;

// 注入server2客户端操作entity2
@Autowired
@Qualifier("esClientServer2")
private RestHighLevelClient esClientServer2;

内容的提问来源于stack exchange，提问作者Dave