网站正在建设中AV_手机版最新的域名网站
本笔记内容为尚硅谷SpringCloud AlibabaSentinel部分
目录
一、Sentinel
1、官网
2、Sentinel是什么
3、下载
4、特性
5、使用
二、安装Sentinel控制台
1、sentinel组件由2部分构成
2、安装步骤
1.下载
2.运行命令
3.访问sentinel管理界面
三、初始化演示工程
四、流控规则
1、基本介绍
解释说明
2、流控模式
1.直接(默认)
2.关联
3.链路
3、流控效果
1.直接->快速失败(默认的流控处理)
2.预热
3.排队等待
五、降级规则
1、基本介绍
2、降级策略实战
1.RT
2.异常比例
3.异常数
六、热点key限流
1、基本介绍
2、测试代码
3、配置
4、参数例外项
配置
七、系统规则
各项配置参数说明
八、@SentinelResource
1、按资源名称限流+后续处理
2、按照Url地址限流+后续处理
3、客户自定义限流处理逻辑
4、更多注解属性说明
九、服务熔断功能
1、Ribbon系列
2、Feign系列
3、熔断框架比较
十、规则持久化
步骤
一、Sentinel
1、官网
https://github.com/alibaba/Sentinel
中文:https://github.com/alibaba/Sentinel/wiki/%E4%BB%8B%E7%BB%8D
2、Sentinel是什么
类似之前学过的Hystrix
3、下载
Releases · alibaba/Sentinel · GitHub
4、特性
5、使用
查看官网:Spring Cloud Alibaba Reference Documentation
服务使用中的各种问题
- 服务雪崩
- 服务降级
- 服务熔断
- 服务限流
二、安装Sentinel控制台
1、sentinel组件由2部分构成
后台+前台8080
2、安装步骤
1.下载
Releases · alibaba/Sentinel · GitHub
下载到本地sentinel-dashboard-1.7.0.jar
2.运行命令
前提:java8环境正常,8080端口不能被占用
命令:java -jar sentinel-dashboard-1.7.0.jar
3.访问sentinel管理界面
http://localhost:8080,登录账号密码均为sentinel
三、初始化演示工程
1、启动Nacos8848成功
http://localhost:8848/nacos/#/login
2、Module
cloudalibaba-sentinel-service8401
3、POM
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>cloud190805</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>cloudalibaba-sentinel-service8401</artifactId><dependencies><!--SpringCloud ailibaba nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--SpringCloud ailibaba sentinel-datasource-nacos 后续做持久化用到--><dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-datasource-nacos</artifactId></dependency><!--SpringCloud ailibaba sentinel --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--openfeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!-- SpringBoot整合Web组件+actuator --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!--日常通用jar包配置--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>4.6.3</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies></project>
4、YML
server:port: 8401spring:application:name: cloudalibaba-sentinel-servicecloud:nacos:discovery:#Nacos服务注册中心地址server-addr: localhost:8848sentinel:transport:#配置Sentinel dashboard地址dashboard: localhost:8080#默认8719端口,假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口port: 8719management:endpoints:web:exposure:include: '*'
5、主启动
package com.atguigu.springcloud.alibaba;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;@EnableDiscoveryClient
@SpringBootApplication
public class MainApp8401
{public static void main(String[] args) {SpringApplication.run(MainApp8401.class, args);}
}
6、业务类FlowLimitController
package com.atguigu.springcloud.alibaba.controller;import com.atguigu.springcloud.alibaba.service.OrderService;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;@RestController
public class FlowLimitController
{@GetMapping("/testA")public String testA(){return "------testA";}@GetMapping("/testB")public String testB(){return "------testB";}
}
启动Sentinel8080 cmd :java -jar sentinel-dashboard-1.7.0.jar
启动微服务8401
启动8401微服务后查看sentienl控制台,发现什么都没有
Sentinel采用的懒加载说明
执行一次访问即可(http://localhost:8401/testA 和 http://localhost:8401/testB)
效果
结论:sentinel8080正在监控微服务8401
四、流控规则
1、基本介绍
解释说明
2、流控模式
1.直接(默认)
直接->快速失败(系统默认)
配置及说明
2.关联
当关联的资源达到阈值时,就限流自己
当与A关联的资源B达到阀值后,就限流A自己、B惹事,A挂了
配置A
postman模拟并发密集访问testB
访问testB成功
postman里新建多线程集合组
将访问地址添加进新新线程组
Run(大批量线程高并发访问B,导致A失效了)
运行后发现testA挂了,点击访问http://localhost:8401/testA,结果Blocked by Sentinel (flow limiting)
3.链路
多个请求调用了同一个微服务(可以想象当作VIP通道)
3、流控效果
1.直接->快速失败(默认的流控处理)
2.预热
公式:阈值除以coldFactor(默认值为3),经过预热时长后才会达到阈值
官网:流量控制 · alibaba/Sentinel Wiki · GitHub
默认coldFactor为3,即请求 QPS 从 threshold / 3 开始,经预热时长逐渐升至设定的 QPS 阈值。
限流 冷启动:限流 冷启动 · alibaba/Sentinel Wiki · GitHub
WarmUp配置
多次点击http://localhost:8401/testB、刚开始不行,后续慢慢OK
应用场景
如:秒杀系统在开启的瞬间,会有很多流量上来,很有可能把系统打死,预热方式就是把为了保护系统,可慢慢的把流量放进来,慢慢的把阀值增长到设置的阀值。
3.排队等待
官网:https://github.com/alibaba/Sentinel/wiki/%E6%B5%81%E9%87%8F%E6%8E%A7%E5%88%B6
测试
五、降级规则
官网:熔断降级 · alibaba/Sentinel Wiki · GitHub
1、基本介绍
RT(平均响应时间,秒级)
平均响应时间 超出阈值 且 在时间窗口内通过的请求>=5,两个条件同时满足后触发降级
窗口期过后关闭断路器
RT最大4900(更大的需要通过-Dcsp.sentinel.statistic.max.rt=XXXX才能生效)
异常比列(秒级)
QPS >= 5 且异常比例(秒级统计)超过阈值时,触发降级;时间窗口结束后,关闭降级
异常数(分钟级)
异常数(分钟统计)超过阈值时,触发降级;时间窗口结束后,关闭降级
Sentinel 熔断降级会在调用链路中某个资源出现不稳定状态时(例如调用超时或异常比例升高),对这个资源的调用进行限制,让请求快速失败,避免影响到其它的资源而导致级联错误。
当资源被降级后,在接下来的降级时间窗口之内,对该资源的调用都自动熔断(默认行为是抛出 DegradeException)。
Sentinel的断路器是没有半开状态的
半开的状态系统自动去检测是否请求有异常,没有异常就关闭断路器恢复使用,有异常则继续打开断路器不可用。具体可以参考Hystrix
2、降级策略实战
1.RT
测试
@GetMapping("/testD")
public String testD()
{//暂停几秒钟线程try { TimeUnit.SECONDS.sleep(1); } catch (InterruptedException e) { e.printStackTrace(); }log.info("testD 测试RT");return "------testD";
}
配置
jmeter压测
结论:
永远一秒钟打进来10个线程(大于5个了)调用testD,我们希望200毫秒处理完本次任务,
如果超过200毫秒还没处理完,在未来1秒钟的时间窗口内,断路器打开(保险丝跳闸)微服务不可用,保险丝跳闸断电了
后续我停止jmeter,没有这么大的访问量了,断路器关闭(保险丝恢复),微服务恢复OK
2.异常比例
测试
@GetMapping("/testD")
public String testD()
{log.info("testD 测试RT");int age = 10/0;return "------testD";
}
配置
jmeter
结论
3.异常数
异常数是按照分钟统计的
测试
@GetMapping("/testE")
public String testE()
{log.info("testE 测试异常比例");int age = 10/0;return "------testE 测试异常比例";
}
配置
jmeter
六、热点key限流
1、基本介绍
官网:https://github.com/alibaba/Sentinel/wiki/热点参数限流
2、测试代码
@SentinelResource
@GetMapping("/testHotKey")
@SentinelResource(value = "testHotKey",blockHandler = "dealHandler_testHotKey")
public String testHotKey(@RequestParam(value = "p1",required = false) String p1, @RequestParam(value = "p2",required = false) String p2){return "------testHotKey";
}
public String dealHandler_testHotKey(String p1,String p2,BlockException exception)
{return "-----dealHandler_testHotKey";
}
3、配置
限流模式只支持QPS模式,固定写死了。(这才叫热点)
@SentinelResource注解的方法参数索引,0代表第一个参数,1代表第二个参数,以此类推
单机阀值以及统计窗口时长表示在此窗口时间超过阀值就限流。
上面的抓图就是第一个参数有值的话,1秒的QPS为1,超过就限流,限流后调用dealHandler_testHotKey支持方法。
测试
4、参数例外项
上述案例演示了第一个参数p1,当QPS超过1秒1次点击后马上被限流
配置
@SentinelResource
处理的是Sentinel控制台配置的违规情况,有blockHandler方法配置的兜底处理;
RuntimeException
int age = 10/0,这个是java运行时报出的运行时异常RunTimeException,@SentinelResource不管
总结
@SentinelResource主管配置出错,运行出错该走异常走异常
七、系统规则
官网:系统自适应限流 · alibaba/Sentinel Wiki · GitHub
各项配置参数说明
八、@SentinelResource
1、按资源名称限流+后续处理
启动Nacos成功:http://localhost:8848/nacos/#/login
启动Sentinel成功:java -jar sentinel-dashboard-1.7.0.jar
Module
1.新建cloudalibaba-sentinel-service8401
2.POM
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>mscloud03</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>cloudalibaba-sentinel-service8401</artifactId><dependencies><!--SpringCloud ailibaba nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><!-- 引入自己定义的api通用包,可以使用Payment支付Entity --><groupId>com.atguigu.springcloud</groupId><artifactId>cloud-api-commons</artifactId><version>${project.version}</version></dependency><!--SpringCloud ailibaba sentinel-datasource-nacos 后续做持久化用到--><dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-datasource-nacos</artifactId></dependency><!--SpringCloud ailibaba sentinel --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--openfeign--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!-- SpringBoot整合Web组件+actuator --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!--日常通用jar包配置--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>4.6.3</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies></project>
3.YML
server:port: 8401spring:application:name: cloudalibaba-sentinel-servicecloud:nacos:discovery:server-addr: localhost:8848 #Nacos服务注册中心地址sentinel:transport:dashboard: localhost:8080 #配置Sentinel dashboard地址port: 8719management:endpoints:web:exposure:include: '*'
4.业务类RateLimitController
package com.atguigu.springcloud.alibaba.controller;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class RateLimitController
{@GetMapping("/byResource")@SentinelResource(value = "byResource",blockHandler = "handleException")public CommonResult byResource(){return new CommonResult(200,"按资源名称限流测试OK",new Payment(2020L,"serial001"));}public CommonResult handleException(BlockException exception){return new CommonResult(444,exception.getClass().getCanonicalName()+"\t 服务不可用");}
}
5.主启动
package com.atguigu.springcloud.alibaba;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;@EnableDiscoveryClient
@SpringBootApplication
public class MainApp8401
{public static void main(String[] args) {SpringApplication.run(MainApp8401.class, args);}
}
配置流控规则
图形配置和代码关系(表示1秒钟内查询次数大于1,就跑到我们自定义的处流,限流)
额外问题:此时关闭问服务8401看看,Sentinel控制台,流控规则消失了-临时(见第十的规则持久化)
2、按照Url地址限流+后续处理
通过访问的URL来限流,会返回Sentinel自带默认的限流处理信息
业务类RateLimitController
package com.atguigu.springcloud.alibaba.controller;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class RateLimitController
{@GetMapping("/byResource")@SentinelResource(value = "byResource",blockHandler = "handleException")public CommonResult byResource(){return new CommonResult(200,"按资源名称限流测试OK",new Payment(2020L,"serial001"));}public CommonResult handleException(BlockException exception){return new CommonResult(444,exception.getClass().getCanonicalName()+"\t 服务不可用");}@GetMapping("/rateLimit/byUrl")@SentinelResource(value = "byUrl")public CommonResult byUrl(){return new CommonResult(200,"按url限流测试OK",new Payment(2020L,"serial002"));}
}
访问:http://localhost:8401/rateLimit/byUrl
Sentinel控制台配置
上面兜底方案面临的问题
- 系统默认的,没有体现我们自己的业务要求。
- 依照现有条件,我们自定义的处理方法又和业务代码耦合在一块,不直观。
- 每个业务方法都添加一个兜底的,那代码膨胀加剧。
- 全局统一的处理方法没有体现。
3、客户自定义限流处理逻辑
创建CustomerBlockHandler类用于自定义限流处理逻辑
1.自定义限流处理类CustomerBlockHandler
package com.atguigu.springcloud.alibaba.myhandler;import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.atguigu.springcloud.alibaba.entities.CommonResult;
import org.springframework.stereotype.Component;public class CustomerBlockHandler
{public static CommonResult handleException(BlockException exception){return new CommonResult(2020,"自定义的限流处理信息......CustomerBlockHandler");}
}
2.RateLimitController
启动微服务后先调用一次http://localhost:8401/rateLimit/customerBlockHandler
3.Sentinel控制台配置
测试后我们自定义的出来了
4、更多注解属性说明
九、服务熔断功能
sentinel整合ribbon+openFeign+fallback
1、Ribbon系列
1.启动nacos和sentinel
2.提供者9003/9004
新建cloudalibaba-provider-payment9003/9004两个一样的做法
POM
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>mscloud03</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>cloudalibaba-provider-payment9003</artifactId><dependencies><!--SpringCloud ailibaba nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><!-- 引入自己定义的api通用包,可以使用Payment支付Entity --><groupId>com.atguigu.springcloud</groupId><artifactId>cloud-api-commons</artifactId><version>${project.version}</version></dependency><!-- SpringBoot整合Web组件 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!--日常通用jar包配置--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies>
</project>
YML(记得修改不同的端口号)
server:port: 9003spring:application:name: nacos-payment-providercloud:nacos:discovery:server-addr: localhost:8848 #配置Nacos地址management:endpoints:web:exposure:include: '*'
主启动
package com.atguigu.springcloud.alibaba;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain9003
{public static void main(String[] args) {SpringApplication.run(PaymentMain9003.class, args);}
}
业务类
package com.atguigu.springcloud.alibaba.controller;import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;import java.util.HashMap;
@RestController
public class PaymentController
{@Value("${server.port}")private String serverPort;public static HashMap<Long,Payment> hashMap = new HashMap<>();static{hashMap.put(1L,new Payment(1L,"28a8c1e3bc2742d8848569891fb42181"));hashMap.put(2L,new Payment(2L,"bba8c1e3bc2742d8848569891ac32182"));hashMap.put(3L,new Payment(3L,"6ua8c1e3bc2742d8848569891xt92183"));}@GetMapping(value = "/paymentSQL/{id}")public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id){Payment payment = hashMap.get(id);CommonResult<Payment> result = new CommonResult(200,"from mysql,serverPort: "+serverPort,payment);return result;}}
测试地址:http://localhost:9003/paymentSQL/1
3.消费者84
新建cloudalibaba-consumer-nacos-order84
POM
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>mscloud03</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>cloudalibaba-consumer-nacos-order84</artifactId><dependencies><!--SpringCloud ailibaba nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--SpringCloud ailibaba sentinel --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!-- 引入自己定义的api通用包,可以使用Payment支付Entity --><dependency><groupId>com.atguigu.springcloud</groupId><artifactId>cloud-api-commons</artifactId><version>${project.version}</version></dependency><!-- SpringBoot整合Web组件 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!--日常通用jar包配置--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies>
</project>
YML
server:port: 84spring:application:name: nacos-order-consumercloud:nacos:discovery:server-addr: localhost:8848sentinel:transport:#配置Sentinel dashboard地址dashboard: localhost:8080#默认8719端口,假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口port: 8719#消费者将要去访问的微服务名称(注册成功进nacos的微服务提供者)
service-url:nacos-user-service: http://nacos-payment-provider
主启动
package com.atguigu.springcloud.alibaba;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@EnableDiscoveryClient
@SpringBootApplication
public class OrderNacosMain84
{public static void main(String[] args) {SpringApplication.run(OrderNacosMain84.class, args);}
}
业务类
ApplicationContextConfig
package com.atguigu.springcloud.alibaba.config;import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;@Configuration
public class ApplicationContextConfig
{@Bean@LoadBalancedpublic RestTemplate getRestTemplate(){return new RestTemplate();}
}
CircleBreakerController
fallback和blockHandler都配置
编码
package com.atguigu.springcloud.alibaba.controller;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import javax.annotation.Resource;
import java.sql.SQLException;
import java.util.concurrent.Executors;@RestController
@Slf4j
public class CircleBreakerController
{public static final String SERVICE_URL = "http://nacos-payment-provider";@Resourceprivate RestTemplate restTemplate;@RequestMapping("/consumer/fallback/{id}")@SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler")public CommonResult<Payment> fallback(@PathVariable Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id,CommonResult.class,id);if (id == 4) {throw new IllegalArgumentException ("非法参数异常....");}else if (result.getData() == null) {throw new NullPointerException ("NullPointerException,该ID没有对应记录");}return result;}public CommonResult handlerFallback(@PathVariable Long id,Throwable e) {Payment payment = new Payment(id,"null");return new CommonResult<>(444,"fallback,无此流水,exception "+e.getMessage(),payment);}public CommonResult blockHandler(@PathVariable Long id,BlockException blockException) {Payment payment = new Payment(id,"null");return new CommonResult<>(445,"blockHandler-sentinel限流,无此流水: blockException "+blockException.getMessage(),payment);}}
sentinel需配置
结果
忽略属性
程序异常打到前台了,对用户不友好
2、Feign系列
2.POM
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>mscloud03</artifactId><groupId>com.atguigu.springcloud</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>cloudalibaba-consumer-nacos-order84</artifactId><dependencies><!--SpringCloud ailibaba nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--SpringCloud ailibaba sentinel --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--SpringCloud openfeign --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!-- 引入自己定义的api通用包,可以使用Payment支付Entity --><dependency><groupId>com.atguigu.springcloud</groupId><artifactId>cloud-api-commons</artifactId><version>${project.version}</version></dependency><!-- SpringBoot整合Web组件 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!--日常通用jar包配置--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies>
</project>
3.YML(激活Sentinel对Feign的支持)
server:port: 84spring:application:name: nacos-order-consumercloud:nacos:discovery:#Nacos服务注册中心地址server-addr: localhost:8848sentinel:transport:#配置Sentinel dashboard地址dashboard: localhost:8080#默认8719端口,假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口port: 8719management:endpoints:web:exposure:include: '*'
# 激活Sentinel对Feign的支持
feign:sentinel:enabled: true
4.业务类
带@FeignClient注解的业务接口(定义接口)
package com.atguigu.springcloud.alibaba.service;import com.atguigu.springcloud.alibaba.entities.CommonResult;
import com.atguigu.springcloud.alibaba.entities.Payment;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;/*** 使用 fallback 方式是无法获取异常信息的,* 如果想要获取异常信息,可以使用 fallbackFactory参数*/
@FeignClient(value = "nacos-payment-provider",fallback = PaymentFallbackService.class)//调用中关闭9003服务提供者
public interface PaymentService
{@GetMapping(value = "/paymentSQL/{id}")public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id);
}
fallback = PaymentFallbackService.class(实现类)
package com.atguigu.springcloud.alibaba.service;import com.atguigu.springcloud.alibaba.entities.CommonResult;
import com.atguigu.springcloud.alibaba.entities.Payment;
import org.springframework.stereotype.Component;@Component
public class PaymentFallbackService implements PaymentService
{@Overridepublic CommonResult<Payment> paymentSQL(Long id){return new CommonResult<>(444,"服务降级返回,没有该流水信息",new Payment(id, "errorSerial......"));}
}
5.Controller
package com.atguigu.springcloud.alibaba.controller;import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import javax.annotation.Resource;@RestController
@Slf4j
public class CircleBreakerController
{public static final String SERVICE_URL = "http://nacos-payment-provider";@Resourceprivate RestTemplate restTemplate;@RequestMapping("/consumer/fallback/{id}")//@SentinelResource(value = "fallback") //没有配置//@SentinelResource(value = "fallback",fallback = "handlerFallback") //fallback只负责业务异常//@SentinelResource(value = "fallback",blockHandler = "blockHandler") //blockHandler只负责sentinel控制台配置违规@SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler",exceptionsToIgnore = {IllegalArgumentException.class})public CommonResult<Payment> fallback(@PathVariable Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id,CommonResult.class,id);if (id == 4) {throw new IllegalArgumentException ("IllegalArgumentException,非法参数异常....");}else if (result.getData() == null) {throw new NullPointerException ("NullPointerException,该ID没有对应记录,空指针异常");}return result;}//本例是fallbackpublic CommonResult handlerFallback(@PathVariable Long id,Throwable e) {Payment payment = new Payment(id,"null");return new CommonResult<>(444,"兜底异常handlerFallback,exception内容 "+e.getMessage(),payment);}//本例是blockHandlerpublic CommonResult blockHandler(@PathVariable Long id,BlockException blockException) {Payment payment = new Payment(id,"null");return new CommonResult<>(445,"blockHandler-sentinel限流,无此流水: blockException "+blockException.getMessage(),payment);}//==================OpenFeign@Resourceprivate PaymentService paymentService;@GetMapping(value = "/consumer/openfeign/{id}")public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id){if(id == 4){throw new RuntimeException("没有该id");}return paymentService.paymentSQL(id);}}
6.主启动
添加@EnableFeignClients启动Feign的功能
package com.atguigu.springcloud.alibaba;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;@EnableDiscoveryClient
@SpringBootApplication
@EnableFeignClients
public class OrderNacosMain84
{public static void main(String[] args) {SpringApplication.run(OrderNacosMain84.class, args);}
}
3、熔断框架比较
十、规则持久化
一旦我们重启应用,sentinel规则将消失,生产环境需要将配置规则进行持久化
将限流配置规则持久化进Nacos保存,只要刷新8401某个rest地址,sentinel控制台的流控规则就能看到,只要Nacos里面的配置不删除,针对8401上sentinel上的流控规则持续有效
步骤
1.修改cloudalibaba-sentinel-service8401
2.POM引入持久化依赖
<!--SpringCloud ailibaba sentinel-datasource-nacos -->
<dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-datasource-nacos</artifactId>
</dependency>
3.YML
添加Nacos数据源配置
server:port: 8401spring:application:name: cloudalibaba-sentinel-servicecloud:nacos:discovery:server-addr: localhost:8848 #Nacos服务注册中心地址sentinel:transport:dashboard: localhost:8080 #配置Sentinel dashboard地址port: 8719datasource:ds1:nacos:server-addr: localhost:8848dataId: cloudalibaba-sentinel-servicegroupId: DEFAULT_GROUPdata-type: jsonrule-type: flowmanagement:endpoints:web:exposure:include: '*'feign:sentinel:enabled: true # 激活Sentinel对Feign的支持
4.添加Nacos业务规则配置
5.启动8401后刷新sentinel发现业务规则有了
6.快速访问测试接口
7.停止8401再看sentinel
结束!