Hystrix实现服务隔离、熔断、降级防止服务雪崩案例

我会带着你远行 2023-07-13 08:22 17阅读 0赞

## 一、新建SpringBoot测试项目，pom依赖如下 ##

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.2.5.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.zhq</groupId>
        <artifactId>hystrix</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>hystrix</name>
        <description>Hystrix实现服务隔离、熔断、降级案例</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>httpclient</artifactId>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.47</version>
            </dependency>
            <dependency>
                <groupId>com.netflix.hystrix</groupId>
                <artifactId>hystrix-metrics-event-stream</artifactId>
                <version>1.5.12</version>
            </dependency>
            <dependency>
                <groupId>com.netflix.hystrix</groupId>
                <artifactId>hystrix-javanica</artifactId>
                <version>1.5.12</version>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
                <exclusions>
                    <exclusion>
                        <groupId>org.junit.vintage</groupId>
                        <artifactId>junit-vintage-engine</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

## 二、案例核心代码 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1_size_16_color_FFFFFF_t_70][]

1）、新建TestController类编写两个没有配置Hystrix的接口，一个配置了Hystrix的接口

@RestController
    public class TestController {
    
        @Autowired
        private TestService testService;
    
    
        /**
         * 没有配置Hystrix的API01
         * @return
         */
        @RequestMapping("/noHystrixApi01")
        public Object noHystrixApi01(){
            JSONObject baidu =testService.getBaidu();
            System.out.println("当前线程名称:" + Thread.currentThread().getName() + ",订单服务调用会员服务:member:" + baidu);
            return baidu;
        }
    
        /**
         * 没有配置Hystrix的API02
         * @return
         */
        @RequestMapping("/noHystrixApi02")
        public Object noHystrixApi02(){
            JSONObject baidu =testService.getBaidu();
            System.out.println("当前线程名称:" + Thread.currentThread().getName() + ",订单服务调用会员服务:member:" + baidu);
            return baidu;
        }
    
        /**
         * 有配置Hystrix的API
         * @return
         */
        @RequestMapping("/hystrixApi")
        public Object hystrixApi(){
            return new HaveHystrixTestApiService(testService).execute();
        }
    
    
    }

2）、其中TestService代码

@Service
    public class TestService {
    
        public JSONObject getBaidu() {
            return HttpClientUtils.httpGet("http://www.baidu.com");
        }
    }

3）、配置 Hystrix的核心代码HaveHystrixTestApiService

原理：

1、 使用线程池隔离可以完全隔离第三方应用，请求线程可以快速放回。 2、 请求线程可以继续接受新的请求，如果出现问题线程池隔离是独立的不会影响其他应用。   
3、 当失败的应用再次变得可用时，线程池将清理并可立即恢复，而不需要一个长时间的恢复。   
4、 独立的线程池提高了并发性

缺点：   
线程池隔离的主要缺点是它们增加计算开销（CPU）。每个命令的执行涉及到排队、调度和上 下文切换都是在一个单独的线程上运行的。

public class HaveHystrixTestApiService extends HystrixCommand<JSONObject> {
        @Autowired
        private TestService testService;
    
        public HaveHystrixTestApiService(TestService testService) {
            super(setter());
            this.testService = testService;
        }
    
        private static Setter setter() {
    
            // 服务分组
            HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey("testGroup");
            // 服务标识
            HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey("test");
            // 线程池名称
            HystrixThreadPoolKey threadPoolKey = HystrixThreadPoolKey.Factory.asKey("test-pool");
            // #####################################################
            // 线程池配置 线程池大小为10,线程存活时间15秒 队列等待的阈值为100,超过100执行拒绝策略
            HystrixThreadPoolProperties.Setter threadPoolProperties = HystrixThreadPoolProperties.Setter().withCoreSize(10)
                    .withKeepAliveTimeMinutes(15).withQueueSizeRejectionThreshold(100);
            // ########################################################
            // 命令属性配置Hystrix 开启超时
            HystrixCommandProperties.Setter commandProperties = HystrixCommandProperties.Setter()
                    // 采用线程池方式实现服务隔离
                    .withExecutionIsolationStrategy(HystrixCommandProperties.ExecutionIsolationStrategy.THREAD)
                    // 禁止
                    .withExecutionTimeoutEnabled(false);
            return HystrixCommand.Setter.withGroupKey(groupKey).andCommandKey(commandKey).andThreadPoolKey(threadPoolKey)
                    .andThreadPoolPropertiesDefaults(threadPoolProperties).andCommandPropertiesDefaults(commandProperties);
    
        }
    
        @Override
        protected JSONObject run() throws Exception {
            JSONObject baidu = testService.getBaidu();
            System.out.println("当前线程名称:" + Thread.currentThread().getName() + ",订单服务调用会员服务:member:" + baidu);
            return baidu;
        }
    
        @Override
        protected JSONObject getFallback() {
            // 如果Hystrix发生熔断，当前服务不可用,直接执行Fallback方法
            System.out.println("系统错误！");
            JSONObject jsonObject = new JSONObject();
            jsonObject.put("code", 500);
            jsonObject.put("msg", "系统错误！");
            return jsonObject;
        }
    }

## 三、通过JMeter测试案例 ##

1）、没做接口保护的时候场景：

当并发请求noHystrixApi01接口线程池资源满，导致noHystrixApi02无法访问

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1_size_16_color_FFFFFF_t_70 2][]

启动以后：

![20200311122433107.png][]

没做接口保护时：虽然我们是并发请求api01但是导致api02也无法访问

其中api01:

![20200311122815949.png][]

api02:

![20200311123612843.png][]

即他们共用一个线程池

2）压测1）时如果访问有配置接口保护的hystrixApi接口

![20200311123924549.png][]

因为走的独立线程池不受影响

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/2020031112110362.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200311122252789.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200311122319436.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3htMzkzMzkyNjI1,size_16,color_FFFFFF,t_70
[20200311122433107.png]: https://img-blog.csdnimg.cn/20200311122433107.png
[20200311122815949.png]: https://img-blog.csdnimg.cn/20200311122815949.png
[20200311123612843.png]: https://img-blog.csdnimg.cn/20200311123612843.png
[20200311123924549.png]: https://img-blog.csdnimg.cn/20200311123924549.png