Linux 安装 Elasticsearch：避坑指南 + 性能调优实战

为什么选择 Elasticsearch？

在开始安装前，我们先简单了解一下为什么 Elasticsearch 成为了当今最流行的搜索引擎之一。

Elasticsearch 是一个基于 Lucene 的分布式、RESTful 风格的搜索和数据分析引擎，具有以下核心优势：

• 实时搜索：毫秒级响应速度
• 分布式架构：易于扩展，可处理 PB 级数据
• 多租户支持：多个索引和类型
• 丰富的查询 DSL：支持复杂查询场景
• 强大的聚合分析：支持复杂数据分析

环境准备与系统要求

在安装 Elasticsearch 之前，我们需要确保系统满足以下要求：

操作系统要求

Elasticsearch 支持多种 Linux 发行版，本文将以 CentOS 8 为例进行讲解，其他发行版的操作类似。

硬件要求

• 最低配置：2 核 CPU，4GB 内存
• 推荐配置：4 核 CPU，8GB 内存（生产环境）

依赖检查

Elasticsearch 需要 Java 环境支持，我们需要安装 Java Development Kit (JDK)。从 Elasticsearch 7.0 开始，官方推荐使用 Java 11。

# 检查是否已安装Java
java -version# 如果未安装，执行以下命令安装OpenJDK 11
sudo dnf install java-11-openjdk-devel -y# 验证安装
java -version

成功安装后，应该看到类似以下输出：

openjdk version "11.0.16" 2022-07-19 LTS
OpenJDK Runtime Environment (Red_Hat-11.0.16.0.8-1.el8_6) (build 11.0.16+8-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-11.0.16.0.8-1.el8_6) (build 11.0.16+8-LTS, mixed mode, sharing)

网络要求

Elasticsearch 默认使用以下端口：

• 9200：HTTP REST API 端口
• 9300：节点间通信端口

确保这些端口在防火墙中开放：

# 开放9200和9300端口
sudo firewall-cmd --zone=public --add-port=9200/tcp --permanent
sudo firewall-cmd --zone=public --add-port=9300/tcp --permanent
sudo firewall-cmd --reload

Elasticsearch 安装步骤

创建专用用户

Elasticsearch 不建议使用 root 用户运行，我们需要创建一个专用用户：

# 创建elasticsearch用户组
sudo groupadd elasticsearch# 创建elasticsearch用户并加入用户组
sudo useradd -m -g elasticsearch elasticsearch# 设置密码（可选）
sudo passwd elasticsearch

下载并安装 Elasticsearch

我们将安装最新的稳定版本 Elasticsearch 8.6.0：

# 切换到临时目录
cd /tmp# 下载Elasticsearch
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-8.6.0-linux-x86_64.tar.gz# 验证文件完整性（可选但推荐）
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-8.6.0-linux-x86_64.tar.gz.sha512
shasum -a 512 -c elasticsearch-8.6.0-linux-x86_64.tar.gz.sha512 # 解压文件
tar -xzf elasticsearch-8.6.0-linux-x86_64.tar.gz# 移动到安装目录
sudo mv elasticsearch-8.6.0 /usr/local/elasticsearch# 修改目录权限
sudo chown -R elasticsearch:elasticsearch /usr/local/elasticsearch

系统配置优化

为了让 Elasticsearch 运行更稳定，我们需要调整一些系统参数：

1. 增加虚拟内存区域数量

Elasticsearch 需要大量的虚拟内存，我们需要调整 vm.max_map_count 参数：

# 临时设置
sudo sysctl -w vm.max_map_count=262144# 永久设置（重启生效）
echo "vm.max_map_count=262144" | sudo tee -a /etc/sysctl.conf# 验证设置
sysctl vm.max_map_count

1. 调整文件描述符限制

Elasticsearch 需要能够打开大量文件描述符：

# 编辑limits.conf文件
sudo vi /etc/security/limits.conf# 在文件末尾添加以下内容
elasticsearch soft nofile 65536
elasticsearch hard nofile 65536
elasticsearch soft nproc 4096
elasticsearch hard nproc 4096

1. 调整系统资源限制

# 编辑配置文件
sudo vi /etc/systemd/system.conf# 添加以下内容
DefaultLimitNOFILE=65536
DefaultLimitNPROC=4096
DefaultLimitMEMLOCK=infinity# 重新加载系统配置
sudo systemctl daemon-reexec

配置 Elasticsearch

Elasticsearch 的主要配置文件位于/usr/local/elasticsearch/config/elasticsearch.yml，我们需要根据实际需求进行配置：

# 切换到elasticsearch用户
sudo su - elasticsearch# 编辑配置文件
vi /usr/local/elasticsearch/config/elasticsearch.yml

基本配置示例：

# 集群名称，同一集群中的所有节点必须使用相同的名称
cluster.name: my-elasticsearch-cluster# 节点名称，每个节点应具有唯一的名称
node.name: node-1# 数据存储路径
path.data: /var/lib/elasticsearch# 日志存储路径
path.logs: /var/log/elasticsearch# 绑定的网络接口，0.0.0.0表示所有接口
network.host: 0.0.0.0# HTTP端口
http.port: 9200# 节点间通信端口
transport.port: 9300# 初始主节点
cluster.initial_master_nodes: ["node-1"]# 允许跨域访问（开发环境）
http.cors.enabled: true
http.cors.allow-origin: "*"# 禁用安全特性（开发环境，生产环境请启用并配置）
xpack.security.enabled: false

注意：在生产环境中，强烈建议启用 xpack.security 并进行相应配置，以确保集群安全。

创建数据和日志目录并设置权限：

# 退出elasticsearch用户，回到root
exit# 创建数据和日志目录
sudo mkdir -p /var/lib/elasticsearch /var/log/elasticsearch# 设置权限
sudo chown -R elasticsearch:elasticsearch /var/lib/elasticsearch
sudo chown -R elasticsearch:elasticsearch /var/log/elasticsearch

内存配置

Elasticsearch 对内存使用非常敏感，我们需要合理配置 JVM 参数：

# 切换到elasticsearch用户
sudo su - elasticsearch# 编辑jvm.options文件
vi /usr/local/elasticsearch/config/jvm.options

根据服务器内存大小调整堆内存：

# 设置堆内存大小，通常为物理内存的一半，但不超过31GB
-Xms4g
-Xmx4g

注意：Elasticsearch 的堆内存不宜设置过大，过大的堆内存会导致垃圾回收时间过长，影响性能。同时，32GB 是一个临界点，超过这个值可以考虑使用压缩普通对象指针 (Compressed Oops)。

启动 Elasticsearch

# 切换到elasticsearch用户
sudo su - elasticsearch# 启动Elasticsearch（后台运行）
/usr/local/elasticsearch/bin/elasticsearch -d# 查看日志，确认启动情况
tail -f /var/log/elasticsearch/my-elasticsearch-cluster.log

成功启动后，日志中会出现类似以下内容：

[2023-03-15T10:00:00,000][INFO ][o.e.n.Node               ] [node-1] started

验证安装

打开另一个终端，执行以下命令验证 Elasticsearch 是否正常运行：

# 检查集群健康状态
curl http://localhost:9200/_cluster/health?pretty

正常情况下，会返回类似以下结果：

{"cluster_name" : "my-elasticsearch-cluster","status" : "green","timed_out" : false,"number_of_nodes" : 1,"number_of_data_nodes" : 1,"active_primary_shards" : 0,"active_shards" : 0,"relocating_shards" : 0,"initializing_shards" : 0,"unassigned_shards" : 0,"delayed_unassigned_shards" : 0,"number_of_pending_tasks" : 0,"number_of_in_flight_fetch" : 0,"task_max_waiting_in_queue_millis" : 0,"active_shards_percent_as_number" : 100.0
}

其中 "status" 为 "green" 表示集群健康状态良好。

设置为系统服务

为了方便管理，我们可以将 Elasticsearch 设置为系统服务：

# 创建服务文件
sudo vi /etc/systemd/system/elasticsearch.service

添加以下内容：

[Unit]
Description=Elasticsearch
Documentation=https://www.elastic.co
Wants=network-online.target
After=network-online.target[Service]
User=elasticsearch
Group=elasticsearch
Environment="ES_HOME=/usr/local/elasticsearch"
Environment="ES_PATH_CONF=/usr/local/elasticsearch/config"
Environment="PID_DIR=/var/run/elasticsearch"
ExecStart=/usr/local/elasticsearch/bin/elasticsearch
Restart=always
WorkingDirectory=/usr/local/elasticsearch
LimitNOFILE=65536
LimitNPROC=4096
LimitMEMLOCK=infinity[Install]
WantedBy=multi-user.target

创建 PID 目录并设置权限：

sudo mkdir -p /var/run/elasticsearch
sudo chown -R elasticsearch:elasticsearch /var/run/elasticsearch

现在可以使用 systemctl 命令管理 Elasticsearch：

# 重新加载系统服务
sudo systemctl daemon-reload# 启动服务
sudo systemctl start elasticsearch# 停止服务
sudo systemctl stop elasticsearch# 重启服务
sudo systemctl restart elasticsearch# 设置开机自启
sudo systemctl enable elasticsearch# 查看服务状态
sudo systemctl status elasticsearch

配置 Elasticsearch 安全特性

在生产环境中，必须启用 Elasticsearch 的安全特性，包括身份验证、授权、加密通信等。

启用安全特性

编辑 elasticsearch.yml 文件，启用 xpack.security：

sudo su - elasticsearch
vi /usr/local/elasticsearch/config/elasticsearch.yml

修改以下配置：

# 启用安全特性
xpack.security.enabled: true# 启用节点间加密通信
xpack.security.transport.ssl.enabled: true

重启 Elasticsearch：

exit  # 退出elasticsearch用户
sudo systemctl restart elasticsearch

设置内置用户密码

Elasticsearch 提供了几个内置用户，我们需要为这些用户设置密码：

sudo su - elasticsearch
/usr/local/elasticsearch/bin/elasticsearch-setup-passwords interactive

按照提示为每个用户设置密码：

Initiating the setup of passwords for reserved users elastic,apm_system,kibana,kibana_system,logstash_system,beats_system,remote_monitoring_user.
You will be prompted to enter passwords as the process progresses.
Please confirm that you would like to continue [y/N]yEnter password for [elastic]: 
Reenter password for [elastic]: 
Enter password for [apm_system]: 
Reenter password for [apm_system]: 
Enter password for [kibana_system]: 
Reenter password for [kibana_system]: 
Enter password for [logstash_system]: 
Reenter password for [logstash_system]: 
Enter password for [beats_system]: 
Reenter password for [beats_system]: 
Enter password for [remote_monitoring_user]: 
Reenter password for [remote_monitoring_user]: 
Changed password for user [apm_system]
Changed password for user [kibana_system]
Changed password for user [kibana]
Changed password for user [logstash_system]
Changed password for user [beats_system]
Changed password for user [remote_monitoring_user]
Changed password for user [elastic]

现在验证需要密码才能访问：

# 使用用户名密码访问
curl -u elastic:your_password http://localhost:9200/_cluster/health?pretty

配置 Elasticsearch 集群

在生产环境中，通常需要部署 Elasticsearch 集群以提高可用性和性能。下面我们介绍如何配置一个包含 3 个节点的集群。

假设我们有 3 台服务器：

• node1: 192.168.1.101
• node2: 192.168.1.102
• node3: 192.168.1.103

在每个节点上按照前面的步骤安装 Elasticsearch，然后分别配置 elasticsearch.yml 文件。

node1 配置

cluster.name: my-elasticsearch-cluster
node.name: node-1
node.master: true
node.data: true
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
network.host: 192.168.1.101
http.port: 9200
transport.port: 9300
discovery.seed_hosts: ["192.168.1.101:9300", "192.168.1.102:9300", "192.168.1.103:9300"]
cluster.initial_master_nodes: ["node-1", "node-2", "node-3"]
xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.client_authentication: required
xpack.security.transport.ssl.keystore.path: certs/elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: certs/elastic-certificates.p12

node2 配置

cluster.name: my-elasticsearch-cluster
node.name: node-2
node.master: true
node.data: true
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
network.host: 192.168.1.102
http.port: 9200
transport.port: 9300
discovery.seed_hosts: ["192.168.1.101:9300", "192.168.1.102:9300", "192.168.1.103:9300"]
cluster.initial_master_nodes: ["node-1", "node-2", "node-3"]
xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.client_authentication: required
xpack.security.transport.ssl.keystore.path: certs/elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: certs/elastic-certificates.p12

node3 配置

cluster.name: my-elasticsearch-cluster
node.name: node-3
node.master: true
node.data: true
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
network.host: 192.168.1.103
http.port: 9200
transport.port: 9300
discovery.seed_hosts: ["192.168.1.101:9300", "192.168.1.102:9300", "192.168.1.103:9300"]
cluster.initial_master_nodes: ["node-1", "node-2", "node-3"]
xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.client_authentication: required
xpack.security.transport.ssl.keystore.path: certs/elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: certs/elastic-certificates.p12

配置集群 SSL 证书

为了确保节点间通信的安全性，我们需要生成 SSL 证书并在所有节点上使用：

# 在node1上生成证书
sudo su - elasticsearch
cd /usr/local/elasticsearch
bin/elasticsearch-certutil cert -out config/certs/elastic-certificates.p12 -pass ""# 设置证书权限
chmod 644 config/certs/elastic-certificates.p12

将生成的证书复制到其他节点：

# 在node1上执行，将证书复制到node2
scp /usr/local/elasticsearch/config/certs/elastic-certificates.p12 elasticsearch@192.168.1.102:/usr/local/elasticsearch/config/certs/# 将证书复制到node3
scp /usr/local/elasticsearch/config/certs/elastic-certificates.p12 elasticsearch@192.168.1.103:/usr/local/elasticsearch/config/certs/

在 node2 和 node3 上设置证书权限：

sudo su - elasticsearch
chmod 644 /usr/local/elasticsearch/config/certs/elastic-certificates.p12

启动集群

在所有节点上启动 Elasticsearch：

exit  # 退出elasticsearch用户
sudo systemctl start elasticsearch

验证集群状态：

curl -u elastic:your_password http://192.168.1.101:9200/_cluster/health?pretty

健康的集群会返回：

{"cluster_name" : "my-elasticsearch-cluster","status" : "green","timed_out" : false,"number_of_nodes" : 3,"number_of_data_nodes" : 3,"active_primary_shards" : 0,"active_shards" : 0,"relocating_shards" : 0,"initializing_shards" : 0,"unassigned_shards" : 0,"delayed_unassigned_shards" : 0,"number_of_pending_tasks" : 0,"number_of_in_flight_fetch" : 0,"task_max_waiting_in_queue_millis" : 0,"active_shards_percent_as_number" : 100.0
}

查看集群节点信息：

curl -u elastic:your_password http://192.168.1.101:9200/_cat/nodes?v

Elasticsearch 基本操作

创建索引

# 创建一个名为"products"的索引
curl -u elastic:your_password -X PUT "http://localhost:9200/products?pretty" -H 'Content-Type: application/json' -d'
{"settings": {"number_of_shards": 3,"number_of_replicas": 1},"mappings": {"properties": {"name": { "type": "text" },"price": { "type": "double" },"category": { "type": "keyword" },"created_at": { "type": "date" }}}
}
'

添加文档

# 添加文档
curl -u elastic:your_password -X POST "http://localhost:9200/products/_doc/1?pretty" -H 'Content-Type: application/json' -d'
{"name": "iPhone 14","price": 7999.00,"category": "手机","created_at": "2023-03-15T10:00:00Z"
}
'# 批量添加文档
curl -u elastic:your_password -X POST "http://localhost:9200/products/_bulk?pretty" -H 'Content-Type: application/json' -d'
{"index":{"_id":"2"}}
{"name":"Samsung Galaxy S23","price":6999.00,"category":"手机","created_at":"2023-03-15T10:30:00Z"}
{"index":{"_id":"3"}}
{"name":"MacBook Pro 16","price":18999.00,"category":"笔记本电脑","created_at":"2023-03-15T11:00:00Z"}
{"index":{"_id":"4"}}
{"name":"Dell XPS 15","price":12999.00,"category":"笔记本电脑","created_at":"2023-03-15T11:30:00Z"}
'

查询文档

# 查询所有文档
curl -u elastic:your_password -X GET "http://localhost:9200/products/_search?pretty" -H 'Content-Type: application/json' -d'
{"query": {"match_all": {}}
}
'# 按条件查询
curl -u elastic:your_password -X GET "http://localhost:9200/products/_search?pretty" -H 'Content-Type: application/json' -d'
{"query": {"match": {"category": "手机"}}
}
'# 范围查询
curl -u elastic:your_password -X GET "http://localhost:9200/products/_search?pretty" -H 'Content-Type: application/json' -d'
{"query": {"range": {"price": {"gte": 8000,"lte": 20000}}}
}
'

更新文档

# 更新文档
curl -u elastic:your_password -X POST "http://localhost:9200/products/_update/1?pretty" -H 'Content-Type: application/json' -d'
{"doc": {"price": 8499.00}
}
'

删除文档

# 删除文档
curl -u elastic:your_password -X DELETE "http://localhost:9200/products/_doc/1?pretty"# 删除索引
curl -u elastic:your_password -X DELETE "http://localhost:9200/products?pretty"

Elasticsearch 性能调优

JVM 调优

1. 堆内存设置

如前所述，堆内存通常设置为物理内存的一半，但不超过 31GB：

-Xms8g
-Xmx8g

1. 垃圾回收器选择

对于 Elasticsearch，推荐使用 G1 垃圾回收器：

-XX:+UseG1GC
-XX:MaxGCPauseMillis=50

1. 内存锁定

确保 Elasticsearch 能够锁定内存，防止被交换到磁盘：

-Xms8g
-Xmx8g
-XX:+AlwaysPreTouch
-XX:+UseG1GC
-XX:MaxGCPauseMillis=50
-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/var/log/elasticsearch/heapdump.hprof

并在 elasticsearch.yml 中添加：

bootstrap.memory_lock: true

索引优化

1. 合理设置分片和副本

• 分片数量：通常每个分片的大小建议在 20GB 到 50GB 之间
• 副本数量：根据可用性需求设置，生产环境建议至少 1 个副本

# 索引默认设置
index.number_of_shards: 3
index.number_of_replicas: 1

1. 索引刷新间隔

对于写入密集型应用，可以适当增加刷新间隔：

index.refresh_interval: 30s

1. 字段映射优化

• 对不需要分词的字段使用 keyword 类型
• 合理设置 text 字段的 analyzer
• 禁用不需要的字段的_all 字段

操作系统优化

1. 虚拟内存

vm.max_map_count=262144

1. 文件系统

推荐使用 ext4 或 xfs 文件系统，并启用 noatime 选项：

/dev/sdX /var/lib/elasticsearch ext4 defaults,noatime 0 2

1. 网络优化

# 增加TCP连接队列大小
net.core.somaxconn=65535# 增加文件描述符限制
fs.file-max=1000000

与 Java 应用集成

下面我们演示如何在 Java 应用中集成 Elasticsearch，使用最新的 Elasticsearch Java Client 8.6.0。

Maven 依赖

<dependencies><!-- Elasticsearch Java Client --><dependency><groupId>co.elastic.clients</groupId><artifactId>elasticsearch-java</artifactId><version>8.6.0</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.14.2</version></dependency><!-- 日志 --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.30</version><scope>provided</scope></dependency><!-- Spring Boot --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId><version>3.0.4</version></dependency><!-- Swagger3 --><dependency><groupId>org.springdoc</groupId><artifactId>springdoc-openapi-starter-webmvc-ui</artifactId><version>2.1.0</version></dependency>
</dependencies>

Elasticsearch 配置类

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.elasticsearch.client.RestClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import lombok.extern.slf4j.Slf4j;/*** Elasticsearch配置类* * @author ken*/
@Configuration
@Slf4j
public class ElasticsearchConfig {/*** 创建Elasticsearch客户端* * @return ElasticsearchClient实例*/@Beanpublic ElasticsearchClient elasticsearchClient() {// 创建凭证提供器final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();credentialsProvider.setCredentials(AuthScope.ANY,new UsernamePasswordCredentials("elastic", "your_password"));// 创建REST客户端RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200, "http")).setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider)).build();// 创建传输层ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());// 创建API客户端ElasticsearchClient client = new ElasticsearchClient(transport);log.info("Elasticsearch client initialized successfully");return client;}
}

实体类

import co.elastic.clients.elasticsearch._types.mapping.DateProperty;
import co.elastic.clients.elasticsearch._types.mapping.DoubleProperty;
import co.elastic.clients.elasticsearch._types.mapping.KeywordProperty;
import co.elastic.clients.elasticsearch._types.mapping.TextProperty;
import co.elastic.clients.elasticsearch._types.mapping.TypeMapping;
import co.elastic.clients.json.JsonData;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Data;
import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;/*** 产品实体类* * @author ken*/
@Data
public class Product {private String id;private String name;private Double price;private String category;@JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss'Z'")private LocalDateTime createdAt;/*** 获取产品索引的映射配置* * @return TypeMapping实例*/public static TypeMapping getMapping() {Map<String, JsonData> properties = new HashMap<>();// 名称字段：text类型，支持分词搜索TextProperty nameProperty = new TextProperty.Builder().build();properties.put("name", JsonData.of(nameProperty, new JacksonJsonpMapper()));// 价格字段：double类型DoubleProperty priceProperty = new DoubleProperty.Builder().build();properties.put("price", JsonData.of(priceProperty, new JacksonJsonpMapper()));// 分类字段：keyword类型，支持精确匹配和聚合KeywordProperty categoryProperty = new KeywordProperty.Builder().build();properties.put("category", JsonData.of(categoryProperty, new JacksonJsonpMapper()));// 创建时间字段：date类型DateProperty createdAtProperty = new DateProperty.Builder().format("yyyy-MM-dd'T'HH:mm:ss'Z'").build();properties.put("createdAt", JsonData.of(createdAtProperty, new JacksonJsonpMapper()));return new TypeMapping.Builder().properties(properties).build();}
}

服务类

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.elasticsearch._types.query_dsl.MatchQuery;
import co.elastic.clients.elasticsearch._types.query_dsl.Query;
import co.elastic.clients.elasticsearch.core.*;
import co.elastic.clients.elasticsearch.core.search.Hit;
import co.elastic.clients.elasticsearch.indices.CreateIndexRequest;
import co.elastic.clients.elasticsearch.indices.CreateIndexResponse;
import co.elastic.clients.elasticsearch.indices.ExistsRequest;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.util.ObjectUtils;
import java.io.IOException;
import java.util.List;
import java.util.stream.Collectors;/*** 产品服务类，提供与Elasticsearch交互的方法* * @author ken*/
@Service
@RequiredArgsConstructor
@Slf4j
public class ProductService {private final ElasticsearchClient elasticsearchClient;private static final String INDEX_NAME = "products";/*** 创建产品索引* * @return 是否创建成功* @throws IOException 当Elasticsearch操作失败时抛出*/public boolean createProductIndex() throws IOException {// 检查索引是否已存在boolean exists = elasticsearchClient.indices().exists(ExistsRequest.of(e -> e.index(INDEX_NAME)));if (exists) {log.info("Index {} already exists", INDEX_NAME);return false;}// 创建索引CreateIndexRequest request = CreateIndexRequest.of(c -> c.index(INDEX_NAME).mappings(Product.getMapping()).settings(s -> s.numberOfShards("3").numberOfReplicas("1")));CreateIndexResponse response = elasticsearchClient.indices().create(request);log.info("Index {} created: {}", INDEX_NAME, response.acknowledged());return response.acknowledged();}/*** 保存产品* * @param product 产品对象* @return 保存的产品ID* @throws IOException 当Elasticsearch操作失败时抛出*/public String saveProduct(Product product) throws IOException {IndexRequest<Product> request;if (ObjectUtils.isEmpty(product.getId())) {// 生成IDrequest = IndexRequest.of(i -> i.index(INDEX_NAME).document(product));} else {// 使用指定IDrequest = IndexRequest.of(i -> i.index(INDEX_NAME).id(product.getId()).document(product));}IndexResponse response = elasticsearchClient.index(request);log.info("Product saved with id: {}", response.id());return response.id();}/*** 根据ID获取产品* * @param id 产品ID* @return 产品对象，若不存在则返回null* @throws IOException 当Elasticsearch操作失败时抛出*/public Product getProductById(String id) throws IOException {GetResponse<Product> response = elasticsearchClient.get(g -> g.index(INDEX_NAME).id(id), Product.class);if (response.found()) {Product product = response.source();product.setId(response.id());return product;} else {log.info("Product with id {} not found", id);return null;}}/*** 搜索产品* * @param keyword 搜索关键词* @return 产品列表* @throws IOException 当Elasticsearch操作失败时抛出*/public List<Product> searchProducts(String keyword) throws IOException {// 创建匹配查询Query query = MatchQuery.of(m -> m.field("name").query(keyword))._toQuery();// 执行搜索SearchResponse<Product> response = elasticsearchClient.search(s -> s.index(INDEX_NAME).query(query), Product.class);// 处理搜索结果List<Hit<Product>> hits = response.hits().hits();return hits.stream().map(hit -> {Product product = hit.source();product.setId(hit.id());return product;}).collect(Collectors.toList());}/*** 删除产品* * @param id 产品ID* @return 是否删除成功* @throws IOException 当Elasticsearch操作失败时抛出*/public boolean deleteProduct(String id) throws IOException {DeleteResponse response = elasticsearchClient.delete(d -> d.index(INDEX_NAME).id(id));log.info("Product with id {} deleted: {}", id, response.result().name());return response.result() == co.elastic.clients.elasticsearch._types.Result.Deleted;}
}

控制器类

import io.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.Parameter;
import io.swagger.v3.oas.annotations.tags.Tag;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import java.io.IOException;
import java.util.List;/*** 产品控制器，提供REST API接口* * @author ken*/
@RestController
@RequestMapping("/api/products")
@RequiredArgsConstructor
@Slf4j
@Tag(name = "产品管理", description = "产品的CRUD和搜索接口")
public class ProductController {private final ProductService productService;@Operation(summary = "创建产品索引")@PostMapping("/index")public ResponseEntity<Boolean> createIndex() {try {boolean result = productService.createProductIndex();return ResponseEntity.ok(result);} catch (IOException e) {log.error("Failed to create index", e);return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(false);}}@Operation(summary = "保存产品")@PostMappingpublic ResponseEntity<String> saveProduct(@Parameter(description = "产品对象") @RequestBody Product product) {try {String id = productService.saveProduct(product);return ResponseEntity.ok(id);} catch (IOException e) {log.error("Failed to save product", e);return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);}}@Operation(summary = "根据ID获取产品")@GetMapping("/{id}")public ResponseEntity<Product> getProduct(@Parameter(description = "产品ID") @PathVariable String id) {try {Product product = productService.getProductById(id);if (product != null) {return ResponseEntity.ok(product);} else {return ResponseEntity.notFound().build();}} catch (IOException e) {log.error("Failed to get product", e);return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);}}@Operation(summary = "搜索产品")@GetMapping("/search")public ResponseEntity<List<Product>> searchProducts(@Parameter(description = "搜索关键词") @RequestParam String keyword) {try {StringUtils.hasText(keyword, "搜索关键词不能为空");List<Product> products = productService.searchProducts(keyword);return ResponseEntity.ok(products);} catch (IllegalArgumentException e) {return ResponseEntity.badRequest().body(null);} catch (IOException e) {log.error("Failed to search products", e);return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);}}@Operation(summary = "删除产品")@DeleteMapping("/{id}")public ResponseEntity<Boolean> deleteProduct(@Parameter(description = "产品ID") @PathVariable String id) {try {boolean result = productService.deleteProduct(id);return ResponseEntity.ok(result);} catch (IOException e) {log.error("Failed to delete product", e);return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(false);}}
}

常见问题与解决方案

1. 启动失败：max virtual memory areas vm.max_map_count [65530] is too low

解决方案：

# 临时设置
sudo sysctl -w vm.max_map_count=262144# 永久设置
echo "vm.max_map_count=262144" | sudo tee -a /etc/sysctl.conf

2. 启动失败：memory locking requested for elasticsearch process but memory is not locked

解决方案：

1. 确保 elasticsearch.yml 中配置了：

bootstrap.memory_lock: true

1. 确保系统配置中设置了：

LimitMEMLOCK=infinity

1. 重启 Elasticsearch 服务

3. 集群节点无法发现彼此

解决方案：

1. 检查 discovery.seed_hosts 和 cluster.initial_master_nodes 配置是否正确
2. 确保节点间 9300 端口能够通信
3. 检查防火墙设置
4. 对于启用了安全特性的集群，确保 SSL 证书配置正确

4. 堆内存溢出

解决方案：

1. 检查 JVM 堆内存设置是否合理
2. 分析堆转储文件，查找内存泄漏
3. 优化查询和索引操作，避免一次性加载过多数据
4. 考虑增加服务器内存或扩展集群

总结

本文详细介绍了在 Linux 环境下安装和配置 Elasticsearch 的全过程，从单节点部署到集群配置，从基本操作到性能调优，再到与 Java 应用的集成。通过遵循本文的步骤，你应该能够成功部署一个稳定、高效的 Elasticsearch 环境。