Sentinel部署和使用教程

1、部署：通过Docker镜像 或者 安装包解压到Linux系统的方式

下载docker镜像可参考：https://www.cnblogs.com/xd99/p/18386275

docker run -d --name sentinel-dashboard \
--restart unless-stopped \
-p 8080:8080 \
registry.cn-hangzhou.aliyuncs.com/zxd-docker-images/sentinel-dashboard:1.8.6

 

2、接入项目并持久化

  2.1 引入主依赖和持久化依赖 

        <!--主依赖-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <!--Sentinel和Nacos持久化依赖-->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
            <version>1.8.6</version>
        </dependency>

   2.2 修改nacos中的yml文件

  注：需要手动修改其中的ip地址和账号密码

.yml

 spring:
  cloud: 
    #sentinel控制台
    sentinel:
      # sentinel开关
      enabled: true
      # 是否饥开启饿加载(默认为false) 默认情况下Sentinel会在客户端首次调用的时候进行初始化，开始向控制台发送心跳包
      eager: true
      transport:
        dashboard: 《你的Sentinel部署ip地址》:8082
        client-username: 《Sentinel账号》
        client-password: 《Sentinel密码》
      datasource:
        #限流持久配置
        flow:
          nacos: 
            server-addr: 《你的Nacos部署ip地址》:8848
            username: 《Nacos账号》
            password: 《Nacos密码》
            dataId: sentinel-flow
            groupId: DEFAULT_GROUP
            rule-type: flow
            data-type: json
        # 降级熔断规则配置
        degrade:
          nacos:
            server-addr: 《你的Nacos部署ip地址》:8848
            username: 《Nacos账号》
            password: 《Nacos密码》
            dataId: sentinel-degrade
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: degrade
        # 热点参数限流规则配置
        param-flow:
          nacos:
            server-addr: 《你的Nacos部署ip地址》:8848
            username: 《Nacos账号》
            password: 《Nacos密码》
            dataId: sentinel-param-flow
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: param-flow

        # 系统规则配置
        system:
          nacos:
            server-addr: 《你的Nacos部署ip地址》:8848
            username: 《Nacos账号》
            password: 《Nacos密码》
            dataId: sentinel-system
            groupId: DEFAULT_GROUP
            data-type: json
            rule-type: system

  2.3 配置几个基础的json文件

  

    2.3.1 限流规则

sentinel-flow

 [
    {
   

        "resource": "hello",
        "limitApp": "default",
        "grade": 1,
        "count": 1,
        "strategy": 0,
        "controlBehavior": 0,
        "clusterMode": false
    }
]

    2.3.2 熔断规则

sentinel-degrade

 [
    {
        "count": 1,
        "enable": false,
        "grade": 0,
        "limitApp": "default",
        "minRequestAmount": 1,
        "resource": "hello",
        "slowRatioThreshold": 0.5,
        "statIntervalMs": 1000,
        "strategy": 0,
        "timeWindow": 10
    }
]

    2.3.3 热点限流规则

sentinel-param-flow

 [
  {
    "resource": "service-hotspot",
    "paramIdx": 0,
    "count": 100,
    "grade": 1,
    "durationInSec": 60,
    "controlBehavior": 0,
    "paramFlowItemList": [
      {
        "object": "specific_value",
        "count": 50
      }
    ]
  }
]

    2.3.4 系统规则

sentinel-system

 [
  {
    "grade": 3,
    "count": 0.8
  }
]

持久化参考链接：https://blog.csdn.net/aa35434/article/details/140739516

重启项目进入Sentinel就可以看到上面json定义的规则了

 

3、自定义异常

SentinelExceptionHandler

 package org.auth.exception;

import com.alibaba.csp.sentinel.slots.block.authority.AuthorityException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.HashMap;
import java.util.Map;


@RestControllerAdvice
public class SentinelExceptionHandler {

    /**
     * 限流全局异常
     */
    @ExceptionHandler(FlowException.class)
    public Map handlerFlowException(){
        return new HashMap(){{
            put("code", HttpStatus.TOO_MANY_REQUESTS.value());
            put("msg", "被限流，请稍后重试");
        }};
    }

    /**
     * 熔断全局异常
     */
    @ExceptionHandler(DegradeException.class)
    public Map handlerDegradeException(){
        return new HashMap(){{
            put("code", HttpStatus.TOO_MANY_REQUESTS.value());
            put("msg", "被熔断，请稍后重试");
        }};
    }

    /**
     * 热点限流异常
     */
    @ExceptionHandler(ParamFlowException.class)
    public Map handlerparamFlowException(){
        return new HashMap(){{
            put("code", HttpStatus.TOO_MANY_REQUESTS.value());
            put("msg", "热点限流，请稍后重试");
        }};
    }

    /**
     *  Sentinel 权限拦截全局异常
     */
    @ExceptionHandler(AuthorityException.class)
    @ResponseBody
    public Map handlerAuthorityException(){
        return new HashMap(){{
            put("code", HttpStatus.UNAUTHORIZED.value());
            put("msg", "暂无权限");
        }};
    }
}

参考链接：https://www.cnblogs.com/vipstone/p/17848233.html