Sentinel结合nacos实现规则持久化

一、为什么需要规则持久化？

传统内存模式规则丢失问题
解决方案对比：文件 vs 配置中心
如何选择：Nacos可动态修改配置，且可视化方便

二、环境准备（显式依赖清单）

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-core</artifactId>
    <version>1.8.6</version>
</dependency>

<!-- Sentinel Spring Cloud Starter -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
    <version>2021.0.5.0</version> <!-- 与Spring Boot 2.7.x兼容的版本 -->
</dependency>

<!-- Sentinel Datasource Nacos -->
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-datasource-nacos</artifactId>
    <version>1.8.6</version>
    <!-- 排除旧版本 -->
    <exclusions>
        <exclusion>
            <groupId>com.alibaba.nacos</groupId>
            <artifactId>nacos-client</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<!-- Nacos 配置中心 -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
    <version>2021.0.5.0</version>
</dependency>
<!-- Nacos Client -->
<dependency>
    <groupId>com.alibaba.nacos</groupId>
    <artifactId>nacos-client</artifactId>
    <version>2.1.1</version>
</dependency>

三、Nacos持久化实战

3.1 配置数据源

spring:
  application:
    name: example
  config:
    import:
      - bootstrap.yml #springcloud高版本要求使用import
      - optional:nacos:${spring.application.name}-${spring.profiles.active}.yaml
  cloud:
    sentinel:
      enabled: true
      eager: true
      datasource:
        # 流量控制规则数据源
        flow: #如果没有复杂需求，这样写就能自动跟nacos建立连接并实现持久化
          nacos:
            server-addr: 127.0.0.1:8848
            namespace: f9dc72d2-76ea-43d0-88f9-486111c827c5
            dataId: example-sentinel-flow-rules
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: flow
        # 熔断降级规则数据源
        degrade:
          nacos:
            server-addr: 127.0.0.1:8848
            namespace: f9dc72d2-76ea-43d0-88f9-486111c827c5
            dataId: example-sentinel-degrade-rules
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: degrade
        # 热点参数规则数据源
        param:
          nacos:
            server-addr: 127.0.0.1:8848
            namespace: f9dc72d2-76ea-43d0-88f9-486111c827c5
            dataId: example-sentinel-param-flow-rules
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: param-flow

spring:
  application:
    name: example  # 与服务名保持一致
  cloud:
    nacos:
      config:
        server-addr: localhost:8848
        namespace: f9dc72d2-76ea-43d0-88f9-486111c827c5 #命名空间id
        file-extension: yaml  # 配置文件格式
        group: DEFAULT_GROUP

3.2 Nacos控制台配置示例

[
  {
    "resource": "/articles/{id}",
    "controlBehavior": 0,
    "count": 100,
    "grade": 1,
    "limitApp": "default",
    "strategy": 0
  }
]

四、热点参数限流实战

4.1 接口注解配置

@GetMapping("/hot")
@SentinelResource(
    value = "articleHotSpot",
    blockHandler = "handleHotSpotBlock"
)
public String getHotArticle(
    @RequestParam("articleId") @SentinelHotSpot("articleId") String id) {
    return "热点文章内容";
}

// 降级处理方法
public String handleHotSpotBlock(String id, BlockException ex) {
    return "热点文章访问过于频繁，请稍后再试";
}

4.2 动态规则更新

ParamFlowRuleManager.loadRules(Collections.singletonList(
    new ParamFlowRule("articleHotSpot")
        .setParamIdx(0)
        .setCount(50)
        .setGrade(1)
));

五、最佳实践总结

多环境配置隔离策略
动态规则刷新频率控制

适合读者：

已经掌握Sentinel基础功能的开发者