Spring cloud实战 从零开始一个简单搜索网站_Hystrix断路由的实现(三)

上文已经完成了一个简单的   浏览器 到 Client 到CSDN端的通路

我们的架构是每个博客网址为一个单独的组件， 这里为了方便直接先用CSDN 那个组件复制下

我这里改成 SDN 修改下 application.properties   端口记得改

eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
spring.application.name=sdn
server.port=8983

 

下面是TOMCAT   和 eureka server运行的截图

 

好了 有两个搜索端了，我这里把CSDN  SDN 叫做搜索端了 ， 下面修改下 Client端  让他能分别调用2个组件

我修改了下github上的配置  把我们新建的serviceID加入进去

 

我们会回到Client项目的  ClientService 多了个SDN，需要修改下代码，能让程序自动加载多个HOST（这里只是简单介绍，如果搜索端好几个肯定得改进）

@Service
public class ClientService {@Autowired RestTemplate restTemplate;@Autowiredprivate EurekaClient discoveryClient;@Value("${serviceIds}")public String serviceIds;public String  search(String key,String page) {StringBuffer sb =new StringBuffer();if(serviceIds.contains(",")) {String[] ids = serviceIds.split(",");for(int i=0;i<ids.length;i++) {sb.append(searchDetail(key, page, ids[i]));}}else {sb.append(searchDetail(key, page,serviceIds));}return sb.toString();}public String  searchDetail(String key,String page,String serviceId) {HashMap<String, String> map = new HashMap<>();map.put("key", key);map.put("page", page);String str= restTemplate.getForObject(serviceUrl(serviceId)+"/search?key={key}&page={page}",String.class,map);return str;}@BeanRestTemplate restTemplate() {return new RestTemplate();}public String serviceUrl(String serviceId) {InstanceInfo instance = discoveryClient.getNextServerFromEureka(serviceId, false);return instance.getHomePageUrl();}
}

 

因为数据比较多  我把两个搜索端直接改成返回一个字符串了

@RestController
public class CsdnController {Gson gson = new Gson();@RequestMapping(value = "/search")public String search(@RequestParam("key") String key, @RequestParam("page") String page) {System.out.println("search");ArrayList<HashMap<String, String>> result;try {
//            result = SearchUtil.search(key, "blog", page);
//            return gson.toJson(result);return "i am csdn 1";} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}return null;}
}

public class CsdnController {Gson gson = new Gson();@RequestMapping(value = "/search")public String search(@RequestParam("key") String key, @RequestParam("page") String page) {System.out.println("search");ArrayList<HashMap<String, String>> result;try {
//            result = SearchUtil.search(key, "blog", page);
//            return gson.toJson(result);return "i am sdn 1";} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}return null;}
}

 

这下有两个端了，搜索时间也延长了2倍， 但万一个端有异常  另外一个端良好 怎么办 这时候就需要断路由 hystrix 

 

 在client pom里面导入下 

            <dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-hystrix</artifactId></dependency>

POM 代码

<?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"><modelVersion>4.0.0</modelVersion><groupId>tsearch_web</groupId><artifactId>springtest-client</artifactId><version>0.0.1</version><packaging>jar</packaging><name>springtest-client</name><description>Note Server catch</description><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.1.1.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version><spring-cloud.version>Greenwich.M3</spring-cloud.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-freemarker</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-server</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-config</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-hystrix</artifactId></dependency></dependencies><dependencyManagement><dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>Finchley.RELEASE</version><type>pom</type><scope>import</scope></dependency></dependencies></dependencyManagement><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build><repositories><repository><id>spring-milestones</id><name>Spring Milestones</name><url>https://repo.spring.io/milestone</url><snapshots><enabled>false</enabled></snapshots></repository></repositories></project>

修改下application

@EnableEurekaClient
@SpringBootApplication
@EnableCircuitBreaker
public class SpringtestClientApplication {public static void main(String[] args) {SpringApplication.run(SpringtestClientApplication.class, args);}
}

 

新增个SearchUtil 类

@Component
public class SearchUtil  { @AutowiredRestTemplate restTemplate;@Autowiredprivate EurekaClient discoveryClient;@HystrixCommand(groupKey = "searchDetail1", commandKey = "searchDetail1",fallbackMethod = "stubMyService")public String searchDetail1(String key, String page, String serviceId) {System.out.println("come="+serviceId);HashMap<String, String> map = new HashMap<>();map.put("key", key);map.put("page", page);String str = restTemplate.getForObject(serviceUrl(serviceId) + "/search?key={key}&page={page}", String.class,map);return str;}@HystrixCommand(groupKey = "searchDetail2", commandKey = "searchDetail2",fallbackMethod = "stubMyService")public String searchDetail2(String key, String page, String serviceId) {System.out.println("come="+serviceId);HashMap<String, String> map = new HashMap<>();map.put("key", key);map.put("page", page);String str = restTemplate.getForObject(serviceUrl(serviceId) + "/search?key={key}&page={page}", String.class,map);return str;}public String stubMyService(String key, String page, String serviceId) {return "error";}@BeanRestTemplate restTemplate() {return new RestTemplate();}public String serviceUrl(String serviceId) {InstanceInfo instance = discoveryClient.getNextServerFromEureka(serviceId, false);return instance.getHomePageUrl();}
}

修改下 ClientService 

@Service
public class ClientService {@AutowiredSearchUtil sc;@Value("${serviceIds}")public String serviceIds;public String search(String key, String page) {StringBuffer sb = new StringBuffer();if (serviceIds.contains(",")) {String[] ids = serviceIds.split(",");sb.append(sc.searchDetail1(key, page, ids[0]));sb.append(sc.searchDetail2(key, page, ids[1]));}else {sb.append(sc.searchDetail1(key, page, serviceIds));}return sb.toString();}}

不断刷新 浏览器 好像没啥区别

给CSDN的Client加个超载

@RestController
public class CsdnController {Gson gson = new Gson();@RequestMapping(value = "/search")public String search(@RequestParam("key") String key, @RequestParam("page") String page) {System.out.println("search");ArrayList<HashMap<String, String>> result;try {
//            result = SearchUtil.search(key, "blog", page);
//            return gson.toJson(result);Thread.sleep(5000);return "i am csdn 1";} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}return null;}
}

继续刷新

然后看下控制台   不是说好的垄断吗  为啥 还是进来了 虽然时间减少了

用Hystrix的时候要注意一点  Hystrix的 超时时间一点要大于resttemplete  或者你用 ribbon   

Hystrix 的默认值全在  com.netflix.hystrix.HystrixCommandProperties

这个就是出错次数 private static final Integer default_circuitBreakerRequestVolumeThreshold = 20;// default => statisticalWindowVolumeThreshold: 20 requests in 10 seconds must occur before statistics matter

我们改下 SearchUtil

@Component
public class SearchUtil  { @AutowiredRestTemplate restTemplate;@Autowiredprivate EurekaClient discoveryClient;@HystrixCommand(groupKey = "searchDetail1", commandKey = "searchDetail1",fallbackMethod = "stubMyService",commandProperties = {@HystrixProperty(name = "circuitBreaker.requestVolumeThreshold",value = "5")})public String searchDetail1(String key, String page, String serviceId) {System.out.println("come="+serviceId);HashMap<String, String> map = new HashMap<>();map.put("key", key);map.put("page", page);String str = restTemplate.getForObject(serviceUrl(serviceId) + "/search?key={key}&page={page}", String.class,map);return str;}@HystrixCommand(groupKey = "searchDetail2", commandKey = "searchDetail2",fallbackMethod = "stubMyService")public String searchDetail2(String key, String page, String serviceId) {System.out.println("come="+serviceId);HashMap<String, String> map = new HashMap<>();map.put("key", key);map.put("page", page);String str = restTemplate.getForObject(serviceUrl(serviceId) + "/search?key={key}&page={page}", String.class,map);return str;}public String stubMyService(String key, String page, String serviceId) {return "error";}@BeanRestTemplate restTemplate() {return new RestTemplate();}public String serviceUrl(String serviceId) {InstanceInfo instance = discoveryClient.getNextServerFromEureka(serviceId, false);return instance.getHomePageUrl();}
}

重启下 不断刷新浏览器    发现 searchDetail1方法不执行了  好了  垄断完成 

 

 

我们需要知道组件的当前状态  这时候就需要hystrix的dashbox

POM 中引入

    <dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId></dependency>

修改下ClientApplication 加入dashboard注释

@EnableEurekaClient
@SpringBootApplication
@EnableCircuitBreaker
@EnableHystrixDashboard
public class SpringtestClientApplication {public static void main(String[] args) {SpringApplication.run(SpringtestClientApplication.class, args);}@Beanpublic ServletRegistrationBean getServlet() {HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);registrationBean.setLoadOnStartup(1);registrationBean.addUrlMappings("/hystrix.stream");registrationBean.setName("HystrixMetricsStreamServlet");return registrationBean;}
}

在浏览器输入http://localhost:8881/hystrix 就能看到界面

 

按上面的填写好  点击Monitor Stream就能进入统计页面

写个函数拼命跑 会发现数字多有变化 鼠标放上去可以看到具体说明

public class TestHystic {public static void main(String[]  args) {long time1=System.currentTimeMillis();String b ="";System.out.println(b.length());for(int i=0;i<100;i++) {try {getData();System.out.println("usertime="+(System.currentTimeMillis()-time1));time1=System.currentTimeMillis();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}public static  void  getData() throws Exception {URL serverUrl = new URL("http://localhost:8881/search?key=spring&page=1");HttpURLConnection conn = (HttpURLConnection) serverUrl.openConnection();InputStream in = conn.getInputStream();BufferedReader br =new BufferedReader(new InputStreamReader(in, "UTF-8"));StringBuffer sb= new StringBuffer();String line;while((line=br.readLine())!=null) {sb.append(line);}System.out.println(sb.toString());in.close();}
}