重庆航运建设发展有限公司 网站山东seo多少钱
1. sentinel服务负载均衡测试
sentinel默认开启了负载均衡的轮询模式,为了测试sentinel服务负载均衡的效果,需要先创建两个服务提供者和一个服务消费者。
1.1. 分别创建两个服务提供者-支付服务9003、9004
1. 添加pom依赖: 提供者只需要将自己注册到服务注册中心即可,因此只需要添加spring-cloud-starter-alibaba-nacos-discovery。
<dependencies><!--自定义api--><dependency><groupId>com.atguigu.springboot</groupId><artifactId>cloud-api-commons</artifactId><version>1.0-SNAPSHOT</version></dependency><!--nacos服务发现--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--springboot web--><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--><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>
2. 编写yaml配置文件: 注意给两个服务分配不同的端口9003、9004
server:port: 9003spring:application:name: nacos-payment-providercloud:nacos:discovery:server-addr: localhost:8848management:endpoints:web:exposure:include: "*"
3. 创建主启动类
@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain9003 {public static void main(String[] args) {SpringApplication.run(PaymentMain9003.class,args);}
}
4. 创建业务类
package com.atguigu.alibaba.controller;import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import lombok.extern.slf4j.Slf4j;
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;/*** @author 强浩* @version 1.0.0* Copyright(c) YTANG All Rights Reserved* @className* @project 管理系统* @date 2022年09月14日*/
@RestController
@Slf4j
public class PaymentController {@Value("${server.port}")private String serverPort;//模拟数据库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"));}//传入id获取数据@GetMapping(value = "/paymentSQL/{id}")public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id){Payment payment = hashMap.get(id);CommonResult<Payment> commonResult = new CommonResult(200, "from mysql,serverPort: " + serverPort, payment);return commonResult;}
}
2. 创建服务消费者-订单服务84
1. 添加pom依赖: 因为之后需要使用sentinel进行限流,所以需要添加sentinel的依赖
<dependencies><dependency><groupId>com.atguigu.springboot</groupId><artifactId>cloud-api-commons</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><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><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>
2. 配置application.yaml文件:
server:port: 84spring:application:name: nacos-order-consumercloud:nacos:discovery:server-addr: localhost:8848sentinel:transport:dashboard: localhost:8080port: 8719server_url:payment_provider: http://nacos-payment-provider
3. 创建主启动类:
@SpringBootApplication
@EnableDiscoveryClient
public class OrderMain84 {public static void main(String[] args) {SpringApplication.run(OrderMain84.class,args);}
}
4. 创建RestTemplate服务调用配置类:
package com.atgugui.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;/*** @author 强浩* @version 1.0.0* Copyright(c) YTANG All Rights Reserved* @className* @project 管理系统* @date 2022年09月14日*/
@Configuration
public class ApplicationContextConfig {@Bean@LoadBalancedpublic RestTemplate getRestTemplate(){return new RestTemplate();}
}
5. 创建业务类: 注入RestTemplate进行远程服务调用
package com.atgugui.alibaba.controller;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.RestController;
import org.springframework.web.client.RestTemplate;import javax.annotation.Resource;/*** @author 强浩* @version 1.0.0* Copyright(c) YTANG All Rights Reserved* @className* @project 管理系统* @date 2022年09月14日*/
@RestController
@Slf4j
public class CircleBreakerController {public static final String SERVER_URL = "http://nacos-payment-provider";@Resourceprivate RestTemplate restTemplate;@GetMapping("/consumer/fallback/{id}")public CommonResult<Payment> fallback(@PathVariable("id") Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVER_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;}
}
5. 测试访问: 查看负载均衡的轮询效果
访问 http://localhost:84/consumer/fallback/1,多次访问,通过观察端口号可以发现,对支付服务进行了轮询访问。
2. fallback-业务错误处理
fallback只负责业务异常
1. 添加@SentinelResource注解,并配置fallback参数,指定服务降级处理方法
@GetMapping("/consumer/fallback/{id}")@SentinelResource(value = "fallback", fallback = "handlerFallback")//指定fallback服务降级处理方法public CommonResult<Payment> fallback(@PathVariable("id") Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVER_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;}public CommonResult<Payment> 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);}
2. 测试: http://localhost:84/consumer/fallback/5,在没有降级处理的时候会直接报错,添加了fallback后进入降级处理方法。
3. blockHandler-限流规则处理
blockHandler处理违反了限流规则的请求
1. 给fallback方法资源添加限流规则
2. 配置@SentinelResource的blockHandler参数指定流控服务降级方法
@GetMapping("/consumer/fallback/{id}")@SentinelResource(value = "fallback", blockHandler = "blockHandler")public CommonResult<Payment> fallback(@PathVariable("id") Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVER_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;}public CommonResult<Payment> 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);}
3. 测试:http://localhost:84/consumer/fallback/5
4. 服务熔断fallback和blockHandler同时配置
blockHandler和fallback 都进行了配置,则被限流降级而抛出BlockException时只会进入blockHandler处理逻辑。也就是说会优先处理服务限流,保证高可用,不要卡死服务器。
@RestController
@Slf4j
public class CircleBreakerController {public static final String SERVER_URL = "http://nacos-payment-provider";@Resourceprivate RestTemplate restTemplate;@GetMapping("/consumer/fallback/{id}")@SentinelResource(value = "fallback", blockHandler = "blockHandler", fallback = "handlerFallback")public CommonResult<Payment> fallback(@PathVariable("id") Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVER_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;}public 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);}public CommonResult<Payment> 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);}
}
5. exceptionsToIgnore忽略指定异常
@RestController
@Slf4j
public class CircleBreakerController {public static final String SERVER_URL = "http://nacos-payment-provider";@Resourceprivate RestTemplate restTemplate;@GetMapping("/consumer/fallback/{id}")@SentinelResource(value = "fallback", blockHandler = "blockHandler", fallback = "handlerFallback",exceptionsToIgnore = IllegalArgumentException.class)public CommonResult<Payment> fallback(@PathVariable("id") Long id){CommonResult<Payment> result = restTemplate.getForObject(SERVER_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;}public 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);}public CommonResult<Payment> 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);}}
设置了忽略IllegalArgumentException异常,当出现该异常时不会进入降级逻辑。
6. sentinel整合openFeign实现服务熔断降级
一般在消费端添加feign组件实现服务降级:在84消费端添加openFeign的依赖,实现服务的熔断降级。
1. 引入openFeign的pom依赖: 这里因为版本冲突问题,需要将devtools组件取消掉,目前具体冲突原因还不知道。
<dependencies><dependency><groupId>com.atguigu.springboot</groupId><artifactId>cloud-api-commons</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--添加openFeign依赖--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId><version>0.2.2.RELEASE</version></dependency><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><!--<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>
2. 修改yaml文件,添加fegin对sentinel的支持:
server:port: 84spring:application:name: nacos-order-consumercloud:nacos:discovery:server-addr: localhost:8848sentinel:transport:dashboard: localhost:8080port: 8719server_url:payment_provider: http://nacos-payment-providerfeign:sentinel:enabled: true
3. 在主启动类开启openFeign:
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class OrderMain84 {public static void main(String[] args) {SpringApplication.run(OrderMain84.class,args);}
}
4. 编写业务类: 使用@FeignClient注解,指定要进行访问的微服务名称,和发生熔断时所要调用的fallback方法
@FeignClient(value = "nacos-payment-provider",fallback = PaymentFallbackServiceImpl.class)
public interface PaymentService {@GetMapping(value = "/paymentSQL/{id}")public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id);
}
5. 服务降级方法实现类: 相当于给PaymentService增加了一个实现类,在发生熔断的情况下自动调用方法的fallback实现,来快速返回结果,防止系统卡死。
@Service
public class PaymentFallbackServiceImpl implements PaymentService {@Overridepublic CommonResult<Payment> paymentSQL(Long id) {return new CommonResult<>(44444,"服务降级返回,---PaymentFallbackService",new Payment(id,"errorSerial"));}
}
6. 现在就可以使用openFeign进行远程服务调用,我们只需要像之前一样将服务接口注入到controller层中,即可实现无感的远程服务调用了:
@RestController
@Slf4j
public class CircleBreakerController {//注入openFeign远程调用接口@Resourceprivate PaymentService paymentService;@GetMapping(value = "/consumer/paymentSQL/{id}")public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id){CommonResult<Payment> result = paymentService.paymentSQL(id);return result;}
}
7. 测试: 访问 http://localhost:84/consumer/paymentSQL/2,此时将9003服务提供者断开,84消费侧自动降级,不会被耗死。
7. 各熔断框架比较
Sentinel | Hystrix | resilience4j | |
---|---|---|---|
隔离策略 | 信号量隔离(并发线程数限流) | 线程池隔商/信号量隔离 | 信号量隔离 |
熔断降级策略 | 基于响应时间、异常比率、异常数 | 基于异常比率 | 基于异常比率、响应时间 |
实时统计实现 | 滑动窗口(LeapArray) | 滑动窗口(基于RxJava) | Ring Bit Buffer |
动态规则配置 | 支持多种数据源 | 支持多种数据源 | 有限支持 |
拓展性 | 多个扩展点 | 插件的形式 | 接口的形式 |
基于注解的支持 | 支持 | 支持 | 支持 |
限流 | 基于QPS,支持基于调用关系的限流 | 有限的支持 | Rate Limiter |
流量整形 | 支持预热模式匀速器模式、预热排队模式 | 不支持 | 简单的Rate Limiter模式 |
系统自适应保护 | 支持 | 不支持 | 不支持 |
控制台 | 提供开箱即用的控制台,可配置规则、查看秒级监控,机器发观等 | 简单的监控查看 | 不提供控制台,可对接其它监控系统 |