springcloud 限流之微服务之间的调用

分手后的思念是犯贱 2022-12-26 10:26 248阅读 0赞

1.引入Sentinel jar包：

<dependency>
         <groupId>com.alibaba.csp</groupId>
         <artifactId>sentinel-annotation-aspectj</artifactId>
         <version>1.4.1</version>
    </dependency>

流量控制(Flow Control)，原理是监控应用流量的QPS或并发线程数等指标，当达到指定阈值时对流量进行控制，避免系统被瞬时的流量高峰冲垮，保障应用高可用性。

2.定义所有限流规则的集合List<FlowRule>，启动时需要加载该令牌，并将规则增加到令牌桶

public void initFlowQpsRule() {
            List<FlowRule> rules = new ArrayList<FlowRule>();
            FlowRule rule1 = new FlowRule();
            rule1.setResource("getOrderInfo");//定义要保护的资源
            // QPS控制在2以内
            rule1.setCount(2);
            // QPS限流
            rule1.setGrade(RuleConstant.FLOW_GRADE_QPS);
            rule1.setLimitApp("default");
            rules.add(rule1);
            FlowRuleManager.loadRules(rules);
        }

3.Sentinel切面类配置：

@Configuration
    public class SentinelAspectConfiguration {
    
        @Bean
        public SentinelResourceAspect sentinelResourceAspect() {
            return new SentinelResourceAspect();
        }
    }

/**
         * 订单查询接口, 使用Sentinel注解实现限流
         *
         * @param orderId
         * @return
         */
        @SentinelResource(value = "getOrderInfo", blockHandler = "handleFlowQpsException",
                fallback = "queryOrderInfo2Fallback")
        public String queryOrderInfo2(String orderId) {
    
            // 模拟接口运行时抛出代码异常
            if ("000".equals(orderId)) {
                throw new RuntimeException();
            }
    
            System.out.println("获取订单信息:" + orderId);
            return "return OrderInfo :" + orderId;
        }
    
        /**
         * 订单查询接口抛出限流或降级时的处理逻辑（阻塞时调用的方法）
         *
         * 注意: 方法参数、返回值要与原函数保持一致 ,参数一定要有BlockException，其它的参数和原参数一致
         * @return
         */
        public String handleFlowQpsException(String orderId, BlockException e) {
            e.printStackTrace();
            return "handleFlowQpsException for queryOrderInfo2: " + orderId;
        }
    
        /**
         * 订单查询接口运行时抛出的异常提供fallback处理
         *
         * 注意: 方法参数、返回值要与原函数保持一致
         * @return
         */
        public String queryOrderInfo2Fallback(String orderId, Throwable e) {
            return "fallback queryOrderInfo2: " + orderId;
        }

一般value 的命名规则为类名.方法名

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参考文章：[https://blog.csdn.net/noaman\_wgs/article/details/103328793][https_blog.csdn.net_noaman_wgs_article_details_103328793]

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[https_blog.csdn.net_noaman_wgs_article_details_103328793]: https://blog.csdn.net/noaman_wgs/article/details/103328793