实战：Springboot集成Sentinel实现流量控制、熔断降级、负载保护

# this is sentinel-dashboard dockerfile
# version 1.0
# 基础镜像
FROM openjdk:8-jre
# 维护人
MAINTAINER senfel<187@sina.cn>
#jar
COPY ./sentinel-dashboard.jar /home/app.jar
# 端口
EXPOSE 8109
# 执行命令启动jar
ENTRYPOINT ["java","-jar","/home/app.jar"]

version: '3.3'
services:
  sentinel:
    build: ./
    image: senfel/sentinel-dashboard
    container_name: sentinel-dashboard
    ports:
      - 8109:8109
    environment:
      JVM_OPTS: -server -Xmx512M -Xms512M -XX:MaxMetaspaceSize=256M -XX:CompressedClassSpaceSize=50M -XX:ReservedCodeCacheSize=240M -XX:MaxDirectMemorySize=400M
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "1"
    volumes:
      - "/home/test/demo/sentinel/logs:/root/logs"
      - "/home/test/demo/sentinel/logs:/app-logs"
    command: [
      "--server.port=8109",
      "--logging.file.path=/app-logs"
    ]

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
    <version>2.2.9.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<!--sentinel持久化到nacos 不持久每次重启都会清除规则-->
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-datasource-nacos</artifactId>
    <version>1.8.0</version>
</dependency>

server:
  port: 9999
spring:
  application:
    name: test-demo
  profiles:
    active: uat
  cloud:
    nacos:
      config:
        server-addr: 10.10.18.16:8848,10.10.18.16:2848,10.10.18.16:5848
        username: nacos
        password: nacos
        file-extension: yaml
      discovery:
        server-addr: 10.10.18.16:8848,10.10.18.16:2848,10.10.18.16:5848
        username: nacos
        password: nacos
    sentinel:
      transport:
        dashboard: 10.10.22.174:8109
        port: 8719
      datasource:
        ds1:
          nacos:
            server-addr: 10.10.18.16:8848,10.10.18.16:2848,10.10.18.16:5848
            dataId: test-demo-sentinel.json
            data-type: json
            rule-type: flow
            username: nacos
            password: nacos
#开启sentinel
feign:
  sentinel:
    enabled: true
  circuitbreaker:
    enabled: true

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

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
@Slf4j
public class TestDemoApplication implements ApplicationRunner {
    public static void main(String[] args) {
        SpringApplication.run(TestDemoApplication.class, args);
    }
}

/**
 * testFeign
 * fallback只负责业务异常
 * blockHandler只负责sentinel配置超标
 * 两个都配置，如果都出错，会进入blockHandler
 * @param str
 * @author senfel
 * @date 2023/7/11 14:26
 * @return java.lang.String
 */
@SentinelResource(value = "testFeign",blockHandler = "blockHandler",fallback = "handlerFallback")
@GetMapping("/testFeign")
public String testFeign(String str){
    if(str.contains("y")){
        throw new RuntimeException();
    }
    return testMQService.testFeign(str);
}
/**
 * 异常阻塞处理
 * @param str
 * @author senfel
 * @date 2023/7/11 14:44
 * @return java.lang.String
 */
private String blockHandler(String str, BlockException blockException){
    return "blockHandler"+"-"+str;
}
/**
 * 降级处理
 * @param str
 * @author senfel
 * @date 2023/7/11 14:44
 * @return java.lang.String
 */
private String handlerFallback(String str,Throwable throwable){
    return "handlerFallback"+"-"+str;
}

/**
 * @author senfel
 * @version 1.0
 * @date 2023/7/03 15:04
 */
@Service
@FeignClient(value = "test-demo",fallback = FallbackService.class)
public interface TestService {
    /**
     * 测试sentinel
     */
    @GetMapping("/feign")
    String feign(@RequestParam String str);
}
/**
 * FallbackService
 * @author senfel
 * @version 1.0
 * @date 2023/7/3 15:26
 */
@Service
public class FallbackService implements TestService {
    @Override
    public String feign(String str) {
        return ">>>>>客户端服务降级>>>>>";
    }
}