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SpringCloud微服务框架一套就够（下集）

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作者是一个来自河源的大三在校生，以下笔记都是作者自学之路的一些浅薄经验，如有错误请指正，将来会不断的完善笔记，帮助更多的Java爱好者入门。

文章目录

Spring Cloud Netflix

断路器springcloud Hystrix

服务降级

在springcloud-02-comsumer-openFeign-dept80的Pom.xml

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

修改它的deptController

@RestControllerpublicclassdeptController{@Autowiredprivate deptService deptService;@HystrixCommand(fallbackMethod ="queryAllDept_Hystrix",commandProperties ={@HystrixProperty(name ="execution.isolation.thread.timeoutInMilliseconds",value ="1500")//添加超时服务降级})@RequestMapping("/feign/queryAllDept")public List<dept>queryAllDept(String id){int i = Integer.parseInt(id);if(i<0){thrownewRuntimeException();//此处为了触发服务降级fallback}return deptService.queryAllDept();}//服务降级方法，这个方法直接从上面的正常方法复制过来，把名字修改一下即可，参数类型也和正常的方法要一致public List<dept>queryAllDept_Hystrix(String id){

        List<dept> depts = deptService.queryAllDept();
        depts.add(newdept("1000","Hystrix_fallback"));return depts;}}

主启动类

@SpringBootApplication@EnableFeignClients@EnableHystrix//开启Hystrix功能publicclassspringApplicationFeign80{publicstaticvoidmain(String[] args){

        SpringApplication.run(springApplicationFeign80.class,args);}}

commandProperties支持什么参数属性

我们全局搜索HystrixCommandProperties，往下翻可以看到如下

protectedHystrixCommandProperties(HystrixCommandKey key, HystrixCommandProperties.Setter builder, String propertyPrefix){this.key = key;this.circuitBreakerEnabled =getProperty(propertyPrefix, key,"circuitBreaker.enabled", builder.getCircuitBreakerEnabled(), default_circuitBreakerEnabled);this.circuitBreakerRequestVolumeThreshold =getProperty(propertyPrefix, key,"circuitBreaker.requestVolumeThreshold", builder.getCircuitBreakerRequestVolumeThreshold(), default_circuitBreakerRequestVolumeThreshold);this.circuitBreakerSleepWindowInMilliseconds =getProperty(propertyPrefix, key,"circuitBreaker.sleepWindowInMilliseconds", builder.getCircuitBreakerSleepWindowInMilliseconds(), default_circuitBreakerSleepWindowInMilliseconds);this.circuitBreakerErrorThresholdPercentage =getProperty(propertyPrefix, key,"circuitBreaker.errorThresholdPercentage", builder.getCircuitBreakerErrorThresholdPercentage(), default_circuitBreakerErrorThresholdPercentage);this.circuitBreakerForceOpen =getProperty(propertyPrefix, key,"circuitBreaker.forceOpen", builder.getCircuitBreakerForceOpen(), default_circuitBreakerForceOpen);this.circuitBreakerForceClosed =getProperty(propertyPrefix, key,"circuitBreaker.forceClosed", builder.getCircuitBreakerForceClosed(), default_circuitBreakerForceClosed);this.executionIsolationStrategy =getProperty(propertyPrefix, key,"execution.isolation.strategy", builder.getExecutionIsolationStrategy(), default_executionIsolationStrategy);this.executionTimeoutInMilliseconds =getProperty(propertyPrefix, key,"execution.isolation.thread.timeoutInMilliseconds", builder.getExecutionIsolationThreadTimeoutInMilliseconds(), default_executionTimeoutInMilliseconds);this.executionTimeoutEnabled =getProperty(propertyPrefix, key,"execution.timeout.enabled", builder.getExecutionTimeoutEnabled(), default_executionTimeoutEnabled);this.executionIsolationThreadInterruptOnTimeout =getProperty(propertyPrefix, key,"execution.isolation.thread.interruptOnTimeout", builder.getExecutionIsolationThreadInterruptOnTimeout(), default_executionIsolationThreadInterruptOnTimeout);this.executionIsolationThreadInterruptOnFutureCancel =getProperty(propertyPrefix, key,"execution.isolation.thread.interruptOnFutureCancel", builder.getExecutionIsolationThreadInterruptOnFutureCancel(), default_executionIsolationThreadInterruptOnFutureCancel);this.executionIsolationSemaphoreMaxConcurrentRequests =getProperty(propertyPrefix, key,"execution.isolation.semaphore.maxConcurrentRequests", builder.getExecutionIsolationSemaphoreMaxConcurrentRequests(), default_executionIsolationSemaphoreMaxConcurrentRequests);this.fallbackIsolationSemaphoreMaxConcurrentRequests =getProperty(propertyPrefix, key,"fallback.isolation.semaphore.maxConcurrentRequests", builder.getFallbackIsolationSemaphoreMaxConcurrentRequests(), default_fallbackIsolationSemaphoreMaxConcurrentRequests);this.fallbackEnabled =getProperty(propertyPrefix, key,"fallback.enabled", builder.getFallbackEnabled(), default_fallbackEnabled);this.metricsRollingStatisticalWindowInMilliseconds =getProperty(propertyPrefix, key,"metrics.rollingStats.timeInMilliseconds", builder.getMetricsRollingStatisticalWindowInMilliseconds(), default_metricsRollingStatisticalWindow);this.metricsRollingStatisticalWindowBuckets =getProperty(propertyPrefix, key,"metrics.rollingStats.numBuckets", builder.getMetricsRollingStatisticalWindowBuckets(), default_metricsRollingStatisticalWindowBuckets);this.metricsRollingPercentileEnabled =getProperty(propertyPrefix, key,"metrics.rollingPercentile.enabled", builder.getMetricsRollingPercentileEnabled(), default_metricsRollingPercentileEnabled);this.metricsRollingPercentileWindowInMilliseconds =getProperty(propertyPrefix, key,"metrics.rollingPercentile.timeInMilliseconds", builder.getMetricsRollingPercentileWindowInMilliseconds(), default_metricsRollingPercentileWindow);this.metricsRollingPercentileWindowBuckets =getProperty(propertyPrefix, key,"metrics.rollingPercentile.numBuckets", builder.getMetricsRollingPercentileWindowBuckets(), default_metricsRollingPercentileWindowBuckets);this.metricsRollingPercentileBucketSize =getProperty(propertyPrefix, key,"metrics.rollingPercentile.bucketSize", builder.getMetricsRollingPercentileBucketSize(), default_metricsRollingPercentileBucketSize);this.metricsHealthSnapshotIntervalInMilliseconds =getProperty(propertyPrefix, key,"metrics.healthSnapshot.intervalInMilliseconds", builder.getMetricsHealthSnapshotIntervalInMilliseconds(), default_metricsHealthSnapshotIntervalInMilliseconds);this.requestCacheEnabled =getProperty(propertyPrefix, key,"requestCache.enabled", builder.getRequestCacheEnabled(), default_requestCacheEnabled);this.requestLogEnabled =getProperty(propertyPrefix, key,"requestLog.enabled", builder.getRequestLogEnabled(), default_requestLogEnabled);this.executionIsolationThreadPoolKeyOverride = HystrixPropertiesChainedProperty.forString().add(propertyPrefix +".command."+ key.name()+".threadPoolKeyOverride",(Object)null).build();}

例如：超时降级execution.isolation.thread.timeoutInMilliseconds和服务熔断的circuitBreaker.enabled和circuitBreaker.requestVolumeThreshold等等都在上面可以找到

全局服务降级

实现全局服务降级主要就是靠@DefaultProperties和@HystrixCommand

进入@DefaultProperties

@Target({ElementType.TYPE})@Retention(RetentionPolicy.RUNTIME)@Inherited@Documentedpublic @interfaceDefaultProperties{
    String groupKey()default"";

    String threadPoolKey()default"";

    HystrixProperty[]commandProperties()default{};

    HystrixProperty[]threadPoolProperties()default{};

    Class<?extendsThrowable>[]ignoreExceptions()default{};

    HystrixException[]raiseHystrixExceptions()default{};

    String defaultFallback()default"";}

使用方法：这个注解加到消费者的controller层上，必要配置（defaultFallback）也就是默认服务降级方法名称，然后在需要使用默认服务降级的方法上加上@HystrixCommand（不加任何参数）即可

小坑：注意=======>默认服务降级的方法也就是defaultFallback方法“”不能有任何参数“”，不然就会报错

比如如下配置

@RestController@DefaultProperties(defaultFallback ="queryAllDept_Hystrix")//默认全局服务降级，也就是配置上去后，需要服务降级的方法加上@HystrixCommand不加参数即可publicclassdeptController{@Autowiredprivate deptService deptService;//    @HystrixCommand(fallbackMethod = "queryAllDept_Hystrix",commandProperties = {//            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds",value = "1500")//    })@HystrixCommand//触发全局服务降级@RequestMapping("/feign/queryAllDept")public List<dept>queryAllDept(String id){int i = Integer.parseInt(id);if(i<0){thrownewRuntimeException();}return deptService.queryAllDept(id);}//    //服务降级方法,全局服务降级方法不能有参数public List<dept>queryAllDept_Hystrix(){

        List<dept> depts =newArrayList<>();
        depts.add(newdept("1000","Hystrix_fallback"));return depts;}}

服务熔断

Pom.xml

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

在springcloud-02-provider-dept8001和8002的controller

@RestControllerpublicclassdeptController{private deptService deptService;@Value("${server.port}")private String port;@Autowired@Qualifier("deptServiceImpl")publicvoidsetDeptService(com.boot.service.deptService deptService){this.deptService = deptService;}@GetMapping(path ="/queryAllDept")@HystrixCommand(fallbackMethod ="queryAllDept_Hystrix",commandProperties ={@HystrixProperty(name ="circuitBreaker.enabled",value ="true"),@HystrixProperty(name ="circuitBreaker.requestVolumeThreshold",value ="10"),@HystrixProperty(name ="circuitBreaker.sleepWindowInMilliseconds",value ="20000"),//注意这是毫秒。1秒=1000毫秒@HystrixProperty(name ="circuitBreaker.errorThresholdPercentage",value ="50")})public List<dept>queryAllDept(String id){
        List<dept> depts = deptService.queryAllDept();
        depts.add(newdept("999",port));//        try {//            Thread.sleep(1500);//        } catch (InterruptedException e) {//            e.printStackTrace();//        }if(Integer.parseInt(id)<0){thrownewRuntimeException();}return depts;}/**
     * 服务熔断
     */public List<dept>queryAllDept_Hystrix(String id){

        List<dept> depts = deptService.queryAllDept();
        depts.add(newdept("1066","Break"));return depts;}}

提供者主启动类：

@SpringBootApplication@EnableEurekaClient//eureka客户端@EnableCircuitBreaker//开启服务熔断功能publicclassSpringBootApplication8001{publicstaticvoidmain(String[] args){
        SpringApplication.run(SpringBootApplication8001.class,args);}}

Hystrix-Dashboard

创建子模块springcloud-02-hystrix-Dashboard8110

仪表盘的访问页面：

假如端口号是8110：http://localhost:8110/hystrix

Pom.xml

<dependencies><!--      web和actuator是必备的，******除了gateway网关不能加入web包  --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--        actuator用来监控--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><!--     Hystrix-dashboard--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId></dependency></dependencies>

配置文件没有要求，就修改端口号即可

server:port:8110spring:application:name: hystrixDashboard8110

主启动类：

@SpringBootApplication@EnableHystrixDashboard//开启了Hystrix仪表盘功能publicclassspringBootApplication8110{publicstaticvoidmain(String[] args){
        SpringApplication.run(springBootApplication8110.class,args);}}
Bug：Hystrix仪表盘连接不上

image-20210227124135194

解决方法：在每一个需要监控的模块（比如微服务提供者8001和8002）加上如下配置

1.微服务提供者的Pom.xml

<!--     Hystrix-dashboard（微服务提供者）--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId></dependency>

2.在微服务提供者8001和8002加上一个bean

@SpringBootApplication@EnableEurekaClient//eureka客户端@EnableCircuitBreaker//开启服务熔断功能publicclassSpringBootApplication8001{publicstaticvoidmain(String[] args){
        SpringApplication.run(SpringBootApplication8001.class,args);}//解决Hystrix-dashboard连接不上@Beanpublic ServletRegistrationBean getServlet(){
        HystrixMetricsStreamServlet streamServlet =newHystrixMetricsStreamServlet();
        ServletRegistrationBean registrationBean =newServletRegistrationBean(streamServlet);
        registrationBean.setLoadOnStartup(1);
        registrationBean.addUrlMappings("/hystrix.stream");
        registrationBean.setName("HystrixMetricsStreamServlet");return registrationBean;}}
Bug：Hystrix仪表盘一直是loading

解决方法：用openFeign去调用一下即可

成功页面👇

image-20210227170129598

服务网关springcloud gateway

小坑：1.注意===》gateWay不能有springBoot-Web的启动器，不然会报错。。。。。。。。

小坑（负载均衡）：2.注意==》需要把gateway当作提供者注册到注册中心eureka中，不然不能进行服务网关的负载均衡

服务网关gateway作用：把所有请求都先进入网关gateway，再由gateway进行分发请求，这样的好处就是隐藏分发到的微服务的端口号，安全性更高

配置gateway服务网关

1.创建子模块springcloud-02-gateWay9527

2.打开pom.xml，添加依赖

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

3.application.yml

server:port:9527spring:cloud:gateway:routes:#配置路由-id: providerGateway8001
          uri: http://localhost:8001predicates:#配置断言- Path=/queryAllDept

4.然后再访问http://localhost:9527/queryAllDept?id=1

gateway服务网关负载均衡（lb）

注意：需要把gateway当作提供者“”注册“”到注册中心eureka中，不然不能进行服务网关的负载均衡**

1.先导入这个

<!--        eureka Client--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-client</artifactId></dependency>

2.springBootApplication

@SpringBootApplication@EnableEurekaClientpublicclassspringBootApplication9527{publicstaticvoidmain(String[] args){

        SpringApplication.run(springBootApplication9527.class,args);}}

3.application.yml

server:port:9527spring:application:name: gateway9527
  cloud:gateway:routes:-id: providerGateway8001
          uri: lb://PROVIDER-DEPT
          predicates:- Path=/queryAllDept

eureka:client:fetch-registry:trueregister-with-eureka:trueservice-url:defaultZone: http://eureka-server7001.com:7001/eureka/, http://eureka-server7002.com:7002/eureka/, http://eureka-server7003.com:7003/eureka/

分布式配置中心springcloud config

1.创建gitee或者GitHub，并把配置文件上传到git

image-20210302204336025

我们目的是拉取上面红框的配置文件

分布式配置中心服务器端（server）

2.创建子模块springcloud-02-config-server9001

3.导入依赖

<!--        config-server--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-config-server</artifactId></dependency>

4.application.yml

server:port:9001spring:cloud:config:server:git:default-label: master #文件所在git的分支，默认是masteruri: https://gitee.com/youzhengjie/could-config #这个uri就是文件所在的网页地址。。。。

5.启动类

@SpringBootApplication@EnableConfigServer//开启分布式配置中心服务器端publicclassspringBootApplication9001{publicstaticvoidmain(String[] args){

        SpringApplication.run(springBootApplication9001.class,args);}}

分布式配置中心客户端（client）

1.创建子模块springcloud-02-config-client8002

2.导入依赖（注意：web和config-client必须要导入，特别是web依赖，不导入不行）

<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.cloud</groupId><artifactId>spring-cloud-config-client</artifactId></dependency>

3.主启动类====不用加什么，就一个普通的springBoot启动类即可

4.bootstrap.yml

server:port:8200spring:cloud:config:label: master
      name: application
      uri: http://localhost:9001

5.controller(去测试有没有sys.version，有的话就说明成功了）

@RestControllerpublicclasstestController{@Value("${sys.version}")private String version;@RequestMapping("/getVersion")public String getVersion(){return version;}}

image-20210303204534651

引入springcloud bus消息总线之前。。。。

我们用git去把sys.version更新成1.8

去访问一下config-server

image-20210303204818402

发现config-server是可以立刻更新到的，因为config-server和gitee是直连的。

我们去访问一下config-client

image-20210303204946992

发现还是1.7，只有重新启动config-client项目才能更新成1.8，这是我们要用到actuator的refresh端点，手动刷新。

actuator手动刷新config-client

修改如下：1.在controller加上@RefreshScope

@RestController@RefreshScope//config client刷新注解publicclasstestController{@Value("${sys.version}")private String version;@RequestMapping("/getVersion")public String getVersion(){return version;}}

2.暴露端点

server:port:8200spring:cloud:config:label: master
      name: application
      uri: http://localhost:9001#开启所有端点management:endpoints:web:exposure:include:"*"

3.用postman去发送post刷新请求

前提：1.发送POST请求到uri/actuator/refresh

2.前面几步工作做好，比如@RefreshScope。

image-20210303210634591

就ok了！！！

为什么要引入springcloud bus的原因

感想：假如有20个config-client，我们要去刷新他们，难道一个个去发送post请求/actuator/refresh???那肯定不行，这样可以是可以，但是效率太低了，所以我们就会引入消息总线springcloud bus，一次post刷新请求即可，不管有多少模块需要刷新。很方便

消息总线springcloud Bus

引入消息总线springcloud bus不需要创建新的模块。。。。只需要用config server和config client即可

为什么不需要创建新的模块呢？因为在下面的架构中可以说明一切

1202638-20180521203126866-1299643942

安装rabbitMQ环境

总教程：https://www.cnblogs.com/saryli/p/9729591.html

1.安装erlang

（1.）下载erlang

官网地址：https://www.erlang.org/

下载教程：https://www.cnblogs.com/minily/p/7398445.html

（2.）配置erlang环境

配置教程：https://blog.csdn.net/g6256613/article/details/80191402

需要配置环境变量

image-20210304210138086

image-20210304210211142

（3.）检查是否安装成功

打开cmd，输入erl，有输出说明成功

（4.）下载rabbitMQ

下载地址：https://www.cnblogs.com/saryli/p/9729591.html

。。。。。。。。。。。。省略，在总教程都有。

（5.）最后访问http://localhost:15672，如果访问成功，说明rabbitMQ安装成功

配置springcloud Bus

有了springcloud bus，我们只需要通知config server，config server就会去“”遍历“”config client，一个个发送刷新的通知，就比如一个个发送/actuator/refresh

1.在上面的基础上，config server9001的pom.xml添加依赖

<!--        bus--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bus-amqp</artifactId></dependency>

注意===========》2.config server 9001的application.yml

spring:cloud:config:server:git:default-label: master
          uri: https://gitee.com/youzhengjie/could-config
  rabbitmq:port:5672username: guest
    password: guest
    host: localhost

#########注意：：：：一定要开放bus-refresh端点management:endpoints:web:exposure:include:"bus-refresh"

3.在上面的基础上，config client 8200 的pom.xml

<!--        bus--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bus-amqp</artifactId></dependency>

4.config client 8200的application.yml

spring:cloud:config:label: master
      name: application
      uri: http://localhost:9001rabbitmq:host: localhost
    username: guest
    password: guest
    port:5672

5.在postman发送刷新命令即可。http://localhost:9001/actuator/bus-refresh

image-20210304204839588

标签： 分布式 java spring cloud
本文转载自: https://blog.csdn.net/weixin_50071998/article/details/123352170
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