外部接口大量超时，把整个系统拖垮，引发雪崩！如何解决？

java -Dserver.port=8180 -Dcsp.sentinel.dashboard.server=localhost:8180 -Dproject.name=sentinel-dashboard -jar sentinel-dashboard-1.8.1.jar

// 资源名称为 handle1 @RequestMapping("/handle1")@SentinelResource(value = "handle1", blockHandler = "blockHandlerTestHandler")public String handle1(String params) {     // 业务逻辑处理    return "success";}
// 接口方法 handle1 的兜底方法public String blockHandlerTestHandler(String params, BlockException blockException) {    return "兜底返回";}

<!-- 限流、熔断框架 --><dependency>    <groupId>com.alibaba.csp</groupId>    <artifactId>sentinel-core</artifactId>    <version>1.8.3</version></dependency>

CREATE TABLE `degrade_rule` (  `id` bigint unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',  `resource_name` varchar(256) NOT NULL COMMENT '资源名称',  `count` double NOT NULL COMMENT '慢调用时长，单位 毫秒',  `slow_ratio_threshold` double NOT NULL COMMENT '慢调用比例阈值',  `min_request_amount` int NOT NULL COMMENT '熔断触发的最小请求数',  `stat_interval` int NOT NULL COMMENT '统计时长，单位 毫秒',  `time_window` int NOT NULL COMMENT '熔断时长，单位为 s',  `created_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',  `updated_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '修改时间',  PRIMARY KEY (`id`) USING BTREE,  UNIQUE KEY `uk_resource_name` (`resource_name`)) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb3 COMMENT='熔断规则表';

@Scheduled(cron = "0/10 * * * * ? ")public void loadDegradeRule() {
    List<DegradeRuleDO> degradeRuleDOList = degradeRuleDao.queryAllRule();    if (CollectionUtils.isEmpty(degradeRuleDOList)) {        return;    }
    String newMd5Hex = DigestUtils.md5Hex(JSON.toJSONString(degradeRuleDOList));    if (StringUtils.isBlank(newMd5Hex) || StringUtils.equals(lastMd5Hex, newMd5Hex)) {        return;    }    List<DegradeRule> rules = null;    List<String> resourceNameList = new ArrayList<>();    rules = degradeRuleDOList.stream().map(degradeRuleDO -> {         //资源名，即规则的作用对象        DegradeRule rule = new DegradeRule(degradeRuleDO.getResourceName())                 // 熔断策略，支持慢调用比例/异常比例/异常数策略                .setGrade(CircuitBreakerStrategy.SLOW_REQUEST_RATIO.getType())                //慢调用比例模式下为慢调用临界 RT（超出该值计为慢调用）；异常比例/异常数模式下为对应的阈值                .setCount(degradeRuleDO.getCount())                // 熔断时长，单位为 s                .setTimeWindow(degradeRuleDO.getTimeWindow())                // 慢调用比例阈值                .setSlowRatioThreshold(degradeRuleDO.getSlowRatioThreshold())                //熔断触发的最小请求数，请求数小于该值时即使异常比率超出阈值也不会熔断                .setMinRequestAmount(degradeRuleDO.getMinRequestAmount())                //统计时长（单位为 ms）                .setStatIntervalMs(degradeRuleDO.getStatInterval());        resourceNameList.add(degradeRuleDO.getResourceName());        return rule;    }).collect(Collectors.toList());
    if (CollectionUtils.isNotEmpty(rules)) {        DegradeRuleManager.loadRules(rules);        ConsumerProxyFactory.resourceNameList = resourceNameList;        lastMd5Hex = newMd5Hex;    }
    log.error("[DegradeRuleConfig] 熔断规则加载: " + rules);}

DigestUtils.md5Hex(JSON.toJSONString(degradeRuleDOList));

@Overridepublic Object invoke(Object proxy, Method method, Object[] args) throws Throwable { Class<?> clazz = proxy.getClass().getInterfaces()[0]; String urlCode = clazz.getName() + "#" + method.getName(); if (resourceNameList.contains(urlCode)) {        // 增加熔断处理        Entry entry = null;        try {            entry = SphU.entry(urlCode);            // 远程网络调用，获取结果            responseString = HttpClientUtil.postJsonRequest(url, header, body);        } catch (BlockException blockException) {            // 触发熔断            log.error("degrade trigger !  remote url :{} ", urlCode);            throw new DegradeBlockExcetion(urlCode);        } finally {            if (entry != null) {                entry.exit();            }        }      } else {          // 常规处理，不走熔断判断逻辑          // 省略    }    }