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

java 复制代码

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 {

    @Autowired
    BaseService 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

java 复制代码

package com.learning.springcloud.order.service;

public interface BaseService {

    public String queryC();
}

java 复制代码

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

java 复制代码

server:
  port: 8061

spring:
  application:
    name: order-sentinel
  cloud:
    sentinel:
      transport:
        dashboard: 127.0.0.1:8080
      web-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：

使用注解 @SentinelResource 则无法使用全局异常处理

增加注解 blockHandler 属性以及方法

java 复制代码

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！！！";
    }
}

再次访问可以正常返回流控处理消息