Springboot实现连接多个ElasticSearch数据库

在实际项目中，一个微服务需要与多个不同的ES数据库进行交互。下面介绍这种方式，微服务可以在数据库或数据集群之间保持高效的交互，实现更复杂的业务逻辑。

1. 引入依赖

<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>7.7.1</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client</artifactId>
    <version>7.7.1</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.7.1</version>
</dependency>
<!-- 适用于中大型的集群 -->
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client-sinffer</artifactId>
    <version>7.7.1</version>
</dependency>

2. 配置信息

es:
  httpHosts: 127.0.0.1:9200
  username: elastic1
  password: elastic
test2:
  es:
    httpHosts: 127.0.0.2:9200
    username: elastic2
    password: elastic

3. RestHighLevelClientBuilder

public class RestHighLevelClientBuilder {
	
	public static RestHighLevelClient buildRestHighLevelClient(EsProperties esProperties) throws Exception {
		if (esProperties.getHttpHosts() == null) {
			throw new IllegalArgumentException("es httpHosts must be not empty");
		}
		String[] urls = esProperties.getHttpHosts().split(",");
		Node[] nodes = new Node[urls.length];
		for (int i = 0; i < urls.length; i++) {
			URI uri = new URI(urls[i]);
			nodes[i] = new Node(new HttpHost(uri.getHost(), uri.getPort(), uri.getScheme()));
		}
		
		RestClientBuilder builder = RestClient.builder(nodes);
		/**
		 * 在使用云ES时，提供的是一个域名负载均衡地址（就像一个单节点地址），似乎应该把云ES的地址认为是一直可用
		 */
//		builder.setFailureListener(new RestClient.FailureListener() {
//		    @Override
//		    public void onFailure(Node node) {
//		        log.error("node:{} was failed", node);
//		    }
//		});
		builder.setNodeSelector(NodeSelector.ANY); //default
		builder.setRequestConfigCallback(new RequestConfigCallback() {
			@Override
			public RequestConfig.Builder customizeRequestConfig(RequestConfig.Builder requestConfigBuilder) {
				return requestConfigBuilder.setConnectionRequestTimeout(esProperties.getConnectionRequestTimeout())
						.setConnectTimeout(esProperties.getConnectTimeout())
						.setSocketTimeout(esProperties.getSocketTimeout());
			}
		});
		builder.setHttpClientConfigCallback(new HttpClientConfigCallback() {
			@Override
			public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
				if(StringUtils.hasText(esProperties.getPassword())) {
					CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
					credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(esProperties.getUsername(), esProperties.getPassword()));
					httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
				}
				httpClientBuilder.setKeepAliveStrategy(new DefaultConnectionKeepAliveStrategy() {
					@Override
					public long getKeepAliveDuration(HttpResponse response, HttpContext context) {
						long keepAliveDuration = super.getKeepAliveDuration(response, context);
						if(keepAliveDuration < 0) {// < 0 无限，会跟服务端不一致报SocketTimeout
							return esProperties.getKeepAlive();
						}
						return keepAliveDuration;
					}
				});
//				httpClientBuilder.setConnectionManager(connManager);
//				httpClientBuilder.setConnectionReuseStrategy(reuseStrategy);
				httpClientBuilder.setMaxConnPerRoute(esProperties.getMaxConnPerRoute());
				httpClientBuilder.setMaxConnTotal(esProperties.getMaxConnTotal());
//				httpClientBuilder.setDefaultIOReactorConfig(IOReactorConfig.custom().setIoThreadCount(1).build());
				return httpClientBuilder.setDefaultIOReactorConfig(
						IOReactorConfig.custom().setIoThreadCount(Runtime.getRuntime().availableProcessors()).build());
			}
		});
		return new RestHighLevelClient(builder);
	}
}

4. Es连接配置

@Data
public class EsProperties {
    private boolean shutdownOnUpdateCheck = true;
    private String httpHosts;
    private String username;
    private String password;
    private int connectionRequestTimeout = 3000;//default -1 ;
    private int connectTimeout = 1000;//default 1000
    private int socketTimeout = 30000;//default 30000
    private int keepAlive = 118000;//ES服务端默认应该是120s
    private int maxConnPerRoute = 10;//default 2 , 对同一地址（例如3个节点使用不同ip时，应该会是每个节点最多几个；3个节点使用统一域名时，应该是按一个节点算）,对一个HttpClient对象而言
    private int maxConnTotal = 20;//default 20 , 总和,对一个HttpClient对象而言
    private boolean enabled;


    public RestHighLevelClient buildRestHighLevelClient() throws Exception {
        if(enabled) {
            return RestHighLevelClientBuilder.buildRestHighLevelClient(this);
        }
        return null;
    }
}

5.其他ES连接信息

@Data
@Configuration
@ConditionalOnClass(value = {RestHighLevelClient.class})
@ConfigurationProperties(prefix = "es")
public class Test1EsProperties extends EsProperties {

}

@Data
@Configuration
@ConditionalOnClass(value = {RestHighLevelClient.class})
@ConfigurationProperties(prefix = "test2.es")
public class Test2EsProperties extends EsProperties{

}

6. Es客户端注入Bean

@Configuration
public class EsConfigBean {

    @Autowired
    private Test1EsProperties test1EsProperties;

    @Autowired
    private Test2EsProperties test2EsProperties;

    @Bean
    @Primary
    public RestHighLevelClient client() throws Exception {
        return test1EsProperties.buildRestHighLevelClient();
    }

    @Bean("test2Client")
    public RestHighLevelClient test2Client() throws Exception {
        return test2EsProperties.buildRestHighLevelClient();
    }
}