elasticsearch8集群安装部署使用

1、ES集群环境准备

节点	ip
node-a	192.168.91.136
node-b	192.168.91.134

• host配置如下

192.168.91.136 node-a
192.168.91.134 node-b

创建账号、环境变量设置、系统文件数限制等与单机版一致，单机版演示过xpack.security.http.ssl.enabled: true，使用了自签证书，在此集群环境中设置为false。只演示集群中的通信使用自签证书，首先xpack.security.enabled: true仍需设置为true

2、生成集群内部(transport)安全通信证书

• 生成ca证书

./bin/elasticsearch-certutil ca

默认ca文件名为elastic-stack-ca.p12，同时需要输入ca密码[123456]；

• 生成节点通信证书

./bin/elasticsearch-certutil cert --ca elastic-stack-ca.p12

Enter password for CA (elastic-stack-ca.p12) : [123456]
Please enter the desired output file [elastic-certificates.p12]: 
Enter password for elastic-certificates.p12 :[12345678]

默认证书文件名为elastic-certificates.p12，同时输入证书密码[12345678]；将此证书文件放到各个节点的目录config/certs下

mkdir config/certs
mv elastic-certificates.p12 config/certs/
chown elastic config/certs -R

• 所有节点设置节点通信密码（因每个节点使用相同的证书文件）

./bin/elasticsearch-keystore add xpack.security.transport.ssl.keystore.secure_password
./bin/elasticsearch-keystore add xpack.security.transport.ssl.truststore.secure_password

设置通信证书密码为12345678

3、配置elasticsearch.yml

• node-a节点配置

cluster.name: es8.1.0-cluster
node.name: node-a
network.host: 192.168.91.136
discovery.seed_hosts: ["192.168.91.134"]
cluster.initial_master_nodes: ["192.168.91.136", "192.168.91.134"]

ingest.geoip.downloader.enabled: false
xpack.security.enabled: true
xpack.security.http.ssl:
  enabled: false

xpack.security.transport.ssl:
  enabled: true
  verification_mode: certificate
  keystore.path: certs/elastic-certificates.p12
  truststore.path: certs/elastic-certificates.p12

• node-b节点配置（与node-a节点配置的差异部分，其他配置相同）

node.name: node-b
network.host: 192.168.91.134
discovery.seed_hosts: ["192.168.91.136"]

需要注意discovery.seed_hosts的配置是其他ES节点

• 修改节点密码（每个节点均重置为elastic8888）

./bin/elasticsearch-reset-password --username elastic -i

4、启动集群并进行简单测试

启动集群后，可使用ElasticView查看节点信息

elasticsearch8-cluster

• 建立一个索引，并测试此索引

curl -X PUT -H 'content-type:application/json' -u elastic:elastic8888  http://192.168.91.136:9200/user-index \
-d '{"settings": {
  "number_of_shards": 2,
  "number_of_replicas": 1
}}'

创建一个索引user-index，指定2个分片和1个副本，再从ElasticView控制台上可直观观察；

elasticsearch8-index

可以看到索引有两个主分片，分别在a和b两台机器，且节点互为副本节点

• 创建索引的mapping

curl -X PUT -H 'content-type:application/json' -u elastic:elastic8888 http://192.168.91.136:9200/user-index/_mapping \
-d '{"properties": {
        "name": {
            "type": "keyword"
        },
        "type": {
            "type": "integer"
        },
        "content": {
            "type": "text"
        }
    }
}'

elasticsearch8-index

写入一些测试数据

curl -X POST -H "content-type:application/json;charset=utf-8" -u elastic:elastic8888 http://192.168.91.136:9200/user-index/_create/1 \
-d '{"name":"测试","type":100,"content":"测试永远滴神啊。。。"}'

5、编写客户端连接测试

• 编写pom.xml依赖

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.6.4
         
    
    com.minxyz
    elasticsearch8
    0.0.1-SNAPSHOT
    elasticsearch8
    elasticsearch8
    
        17
    
    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            co.elastic.clients
            elasticsearch-java
            8.1.0
        
        
            com.fasterxml.jackson.core
            jackson-databind
            2.12.3
        

        
            org.glassfish
            jakarta.json
            2.0.1
        

        
            com.alibaba
            fastjson
            1.2.79
        

        
            org.projectlombok
            lombok
            true
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
                
                    
                        
                            org.projectlombok
                            lombok
                        
                    
                
            
        
    

• 编写测试类

package com.minxyz.elasticsearch8;

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.elasticsearch.core.SearchResponse;
import co.elastic.clients.elasticsearch.core.search.Hit;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import com.alibaba.fastjson.JSON;
import com.minxyz.elasticsearch8.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.Header;
import org.apache.http.HttpHost;
import org.apache.http.message.BasicHeader;
import org.elasticsearch.client.RestClient;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.util.Base64Utils;


@Slf4j
@SpringBootTest
class Elasticsearch8ApplicationTests {

    @Test
    void contextLoads() throws Exception {
        String auth = Base64Utils.encodeToString("elastic:elastic8888".getBytes());
        Header authHeader = new BasicHeader("Authorization", String.format("Basic %s", auth));
        Header[] header = {authHeader};
        RestClient restClient = RestClient.builder(new HttpHost("192.168.91.134", 9200), new HttpHost("192.168.91.136", 9200)).setDefaultHeaders(header).build();
        ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
        ElasticsearchClient client = new ElasticsearchClient(transport);
        SearchResponse search = client.search(s -> s.index("user-index").query(q -> q.term(t -> t.field("type").value(v -> v.stringValue("100")))),User.class);
        for (Hit hit : search.hits().hits()) {
            log.info("result: {}", JSON.toJSONString(hit.source()));
        }
        log.info("success");
    }

}

在此处使用了RestClient.builder创建restClient，传入了多个HttpHost，测试的时候可以尝试将134节点关掉，在超时1秒后将连接136查询到数据；