sentinel整合nacos在gateway中实现限流

sentinel整合nacos在gateway中实现限流

一、应用层面完成网关整合nacos和sentinel实现限流

前沿

启动nacos与sentinel的jar的启动，这里不细讲

sentinel官网 https://github.com/alibaba/Sentinel/wiki/%E4%B8%BB%E9%A1%B5
sentinel 下载地址 https://github.com/alibaba/Sentinel/releases
nacos官网 https://nacos.io/zh-cn/docs/deployment.html
nacos下载地址https://github.com/alibaba/nacos/releases

1.1 导报

在gateway中导入所需的jar

 
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-alibaba-sentinel-gatewayartifactId>
            <version>2.2.1.RELEASEversion>
        dependency>
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-sentinelartifactId>
            <version>2.2.1.RELEASEversion>
        dependency>
        <dependency>
            <groupId>com.alibaba.cspgroupId>
            <artifactId>sentinel-datasource-nacosartifactId>
            <version>1.8.0version>
        dependency>
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集成nacos的注册中心与配置中心

   
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
            <version>2.2.1.RELEASEversion>
        dependency>
        
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-configartifactId>
            <version>2.2.1.RELEASEversion>
        dependency>
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1.2 配置文件(仅展示整合sentinel部分)

# 应用名称
spring:
  cloud:
    sentinel:
      transport:
      	# sentinel的连接地址
        dashboard: localhost:7777
        # sentinel与服务的通信端口，只要不冲突就行
        port: 8720
        # 取消控制台懒加载
      eager: true
      # 获取sentinel配置在nacos的文件信息
      datasource:
        ds1:
          nacos:
          	# nacos的地址
            server-addr: ${spring.cloud.nacos.discovery.server-addr}
            # nacos的文件名称
            data-id: gateway-flow-rule-sentinel
            # 在nacos的命名空间  注意public空间下不能设置为public否则获取不到配置，如果在public就不写此行
            namespace: 49dc14c4-e3a6-48de-a773-6fdda300424f   
            # 分组名称
            group-id: DEFAULT_GROUP
            # 文件类型
            data-type: json
              # 规则类型: com.alibaba.cloud.sentinel.datasource.RuleType
              # FlowRule 就是限流规则
            rule-type: gw-flow
        ds2:
          nacos:
            server-addr: ${spring.cloud.nacos.discovery.server-addr}
            data-id: gateway-flow-rule-api-sentinel
            namespace: 49dc14c4-e3a6-48de-a773-6fdda300424f   # 注意public空间下不能显示的设置为public否则获取不到配置
            group-id: DEFAULT_GROUP
            data-type: json
            # 规则类型: com.alibaba.cloud.sentinel.datasource.RuleType
            # FlowRule 就是限流规则
            rule-type: gw-api-group
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1.3 编写配置类

@Slf4j
@Configuration
public class GatewayConfiguration {
    
    private final List<ViewResolver> viewResolvers;
    private final ServerCodecConfigurer serverCodecConfigurer;

    public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,
                                ServerCodecConfigurer serverCodecConfigurer) {
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }

    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
        // Register the block exception handler for Spring Cloud Gateway.
        return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    }

    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public GlobalFilter sentinelGatewayFilter() {
        return new SentinelGatewayFilter();
    }
}
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1.4 编写返回自定义限流拦截信息(如果不写此类返回就是429)

@Configuration
public class SentinelGatewayConfig {
    public SentinelGatewayConfig() {
        GatewayCallbackManager.setBlockHandler(new BlockRequestHandler() {
            @Override
            public Mono<ServerResponse> handleRequest(ServerWebExchange exchange, Throwable t) {
                R error = R.error(500, "限流啦 别在试啦");
                String errorStr = JSON.toJSONString(error);
                Mono<ServerResponse> just = ServerResponse.ok().body(Mono.just(errorStr), String.class);
                return just;
            }
        });
    }
}
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注：如果启动后sentinel的画面没有API菜单，那就在启动类main函数里加上

  // 添加此代码，在Sentinel控制台中做判断使用
        System.setProperty("csp.sentinel.app.type", "1");
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1.5 限流json文件

文件位置

gateway-flow-rule-sentinel的配置内容

[
    {
    "resource": "macro-member",
    "resourceMode": 0,
    "count": 1,
    "intervalSec": 60
  },
  {
    "resource": "macro-member-api",
    "resourceMode": 1,
    "count": 2,
    "intervalSec": 60
   }
  ]
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gateway-flow-rule-api-sentinel

[{
 "apiName": "macro-member-api",
    "predicateItems": [
      {
        "pattern": "/api/member/sysUser/getUsers"
      },
      {
        "pattern": "/imooc/ecommerce-nacos-client/**",
        "matchStrategy": 1
      },
        {
        "pattern": "/api/member/sysUser/getUserByName"
      }
    ]
}]
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1.6 测试

访问效果是达到了限流的目的

nacos的限流规则更改，sentinel控制台能马上感应到

二、sentinel限流原理

Sentinel中的令牌桶算法采用固定窗口算法，将时间窗口分成若干个固定长度的小窗口，并在每个小窗口开始时向令牌桶中添加一定数量的令牌。每次请求需要获取一个令牌才能执行，如果令牌桶中的令牌数量不足，则请求将被拒绝。通过调整每个小窗口的长度和每次添加的令牌数量，可以控制限流的速率

配置参数的含义