Sentinel 流控-链路模式-编程知识

Sentinel 流控-链路模式

链路模式

A B C 三个服务

A 调用 C

B 调用 C

C 设置流控 ->链路模式 -> 入口资源是 A

A、B 服务

package com.learning.springcloud.order.controller;import com.learning.springcloud.order.service.BaseService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** 链路模式：*    条件：*      - A —> C; B -> C*      - C 设置流控规则 入口资源是A*/
@RestController
@RequestMapping("/lianlu")
public class LianLuController {@AutowiredBaseService baseService;@RequestMapping("/A")public Object A() {String s = baseService.queryC();return "hi, A;" + s;}@RequestMapping("/B")public Object B() {String s = baseService.queryC();return "hi, B;" + s;}}

C 服务

package com.learning.springcloud.order.service;public interface BaseService {public String queryC();
}

package com.learning.springcloud.order.service.impl;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.learning.springcloud.order.service.BaseService;
import org.springframework.stereotype.Service;@Service
public class BaseServiceImpl implements BaseService {@Override@SentinelResource(value = "queryC")public String queryC() {return "查询C";}
}

控制台

设置链路收集

server:port: 8061spring:application:name: order-sentinelcloud:sentinel:transport:dashboard: 127.0.0.1:8080web-context-unify: false # 默认请求链路进行收敛

设置流控规则

链路入口 A

访问

问题：为啥没有流控处理的消息而是访问报错？？？

问题解决

分析：

1. 使用注解 @SentinelResource 则无法使用全局异常处理

2. 增加注解 blockHandler 属性以及方法

package com.learning.springcloud.order.service.impl;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.learning.springcloud.order.service.BaseService;
import org.springframework.stereotype.Service;@Service
public class BaseServiceImpl implements BaseService {@Override@SentinelResource(value = "queryC", blockHandler = "blockHandlerForQueryC")public String queryC() {return "查询C";}public String blockHandlerForQueryC(BlockException be) {return "queryC 被流控了！！！";}
}