Question

如果elasticsearch在单一模式下运行，我可以使用以下代码轻松建立RestHighLevel连接：

RestHighLevelClient client = new RestHighLevelClient(
    RestClient.builder(
            new HttpHost("localhost", 9200, "http"),
            new HttpHost("localhost", 9201, "http")));

但是如果我的弹性集群有3台计算机，例如“ host1”，“ host2”，“ host3”，那么如何在集群模式下创建其余的高级客户端？

谢谢

Answer 1

RestHighLevelClient client = new RestHighLevelClient(
        RestClient.builder(
                new HttpHost("host1", 9200, "http"),
                new HttpHost("host2", 9200, "http"),
                new HttpHost("host2", 9200, "http")
        )
);

作为doc it looks like you were referencing states，RestClient.builder接受要连接的HttpHosts数组。客户端（实际上是ES低级REST客户端）将向这些主机轮询请求。另请参见Javadoc。

Answer 2

根据Elasticsearch docs，您可以在RestClient.builder()中传递多个Elasticsearch主机。

更好的解决方案是从配置中加载Elasticsearch主机（在基于Scala的应用程序中为application.conf），而不是在代码库中对其进行硬编码。

这是使用Java Varargs(:_*)的基于Scala的解决方案。

application.conf

es_hosts = ["x.x.x.x","x.x.x.x","x.x.x.x"] // You can even use service-name/service-discovery
es_port = 9200
es_scheme = "http"

代码段

import collection.JavaConverters._
import com.typesafe.config.ConfigFactory
import org.apache.http.HttpHost
import org.elasticsearch.client.{RestClient, RestHighLevelClient}


val config = ConfigFactory.load()
val port = config.getInt(ES_PORT)
val scheme = config.getString(ES_SCHEME)

val es_hosts = config.getStringList(ES_HOSTS).asScala
val httpHosts = es_hosts.map(host => new HttpHost(host, port, scheme))

val low_level_client = RestClient.builder(httpHosts:_*)
val high_level_client: RestHighLevelClient = new RestHighLevelClient(low_level_client)

Answer 3

要使用多个主机创建高级REST客户端，您可以执行以下操作：

String[] esHosts = new String[]{"node1-example.com:9200", "node2-example.com:9200", 
    "node3-example.com:9200"};

final ClientConfiguration clientConfiguration = ClientConfiguration.builder()
    .connectedTo(esHosts)
    .build();

RestHighLevelClient restClient = RestClients.create(clientConfiguration).rest();

// Hostnames used for building client can be verified as following
List<Node> nodes = restClient.getLowLevelClient().getNodes();
nodes.forEach(node -> System.out.println(node.toString()));

参考：

High Level REST Client的文档
ClientConfigurationBuilder的源代码

在弹性集群模式下创建Java RestHighLevelClient

3 个答案: