Dubbo入门

- 日理万妓 2021-11-22 13:48 334阅读 0赞

## 一、 什么是Dubbo ##

Dubbo是一个分布式服务框架，致力于提供高性能和透明化的RPC远程服务调用方案，以及SOA服务治理方案。简单的说，dubbo就是个服务框架，如果没有分布式的需求，其实是不需要用的，只有在分布式的时候，才有dubbo这样的分布式服务框架的需求，并且本质上是个服务调用的东东，说白了就是个`远程服务调用的分布式框架`（告别Web Service模式中的WSdl，以服务者与消费者的方式在dubbo上注册）  
其核心部分包含:

*  远程通讯: 提供对多种基于长连接的NIO框架抽象封装，包括多种线程模型，序列化，以及“请求-响应”模式的信息交换方式。
 *  集群容错: 提供基于接口方法的透明远程过程调用，包括多协议支持，以及软负载均衡，失败容错，地址路由，动态配置等集群支持。
 *  自动发现: 基于注册中心目录服务，使服务消费方能动态的查找服务提供方，使地址透明，使服务提供方可以平滑增加或减少机器。

## 二、Dubbo能做什么 ##

1.  透明化的远程方法调用，就像调用本地方法一样调用远程方法，只需简单配置，没有任何API侵入。
2.  软负载均衡及容错机制，可在内网替代F5等硬件负载均衡器，降低成本，减少单点。
3.  服务自动注册与发现，不再需要写死服务提供方地址，注册中心基于接口名查询服务提供者的IP地址，并且能够平滑添加或删除服务提供者。
4.  Dubbo采用全spring配置方式，透明化接入应用，对应用没有任何API侵入，只需用Spring加载Dubbo的配置即可，Dubbo基于Spring的Schema扩展进行加载。

## 三、Dubbo架构 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3R3dDkzNjQ1Nzk5MQ_size_16_color_FFFFFF_t_70]

#### 3.1节点角色 ####

*  Provider: 暴露服务的服务提供方。
 *  Consumer: 调用远程服务的服务消费方。
 *  Registry: 服务注册与发现的注册中心。
 *  Monitor: 统计服务的调用次调和调用时间的监控中心。
 *  Container: 服务运行容器。

#### 3.2调用关系 ####

1.  服务容器负责启动，加载，运行服务提供者。
2.  服务提供者在启动时，向注册中心注册自己提供的服务。
3.  服务消费者在启动时，向注册中心订阅自己所需的服务。
4.  注册中心返回服务提供者地址列表给消费者，如果有变更，注册中心将基于长连接推送变更数据给消费者。
5.  服务消费者，从提供者地址列表中，基于软负载均衡算法，选一台提供者进行调用，如果调用失败，再选另一台调用。
6.  服务消费者和提供者，在内存中累计调用次数和调用时间，定时每分钟发送一次统计数据到监控中心。

## 四、使用Dubbo可能遇到的问题 ##

1.  **使用Dubbo可能遇到的问题**

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mgmtFactoryInoutDetailsController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'goodsInoutServiceImpl' available
    	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1268) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.web.method.HandlerMethod.createWithResolvedBean(HandlerMethod.java:299) ~[spring-web-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:323) ~[spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:61) ~[spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.handler.AbstractHandlerMapping.getHandler(AbstractHandlerMapping.java:352) ~[spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1160) [spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:940) [spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) [spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) [spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) [spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) [servlet-api.jar:na]
    	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) [servlet-api.jar:na]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) [catalina.jar:8.0.36]
    	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-websocket.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) [catalina.jar:8.0.36]
    	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) [shiro-core-1.2.4.jar:1.2.4]
    	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) [shiro-core-1.2.4.jar:1.2.4]
    	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) [shiro-core-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) [shiro-web-1.2.4.jar:1.2.4]
    	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) [shiro-web-1.2.4.jar:1.2.4]
    	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:347) [spring-web-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:263) [spring-web-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) [catalina.jar:8.0.36]
    	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) [spring-web-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) [catalina.jar:8.0.36]
    	at ue.common.filter.MultiPrefixHideUrlFilter.doFilter(MultiPrefixHideUrlFilter.java:76) [YKXCommon-3.3.01.jar:na]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) [catalina.jar:8.0.36]
    	at ue.common.filter.PageableFilter.doFilterInternal(PageableFilter.java:48) [YKXCommon-3.3.01.jar:na]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.20.RELEASE.jar:4.3.20.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) [catalina.jar:8.0.36]
    	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) [catalina.jar:8.0.36]
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [catalina.jar:8.0.36]
    	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) [catalina.jar:8.0.36]
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [catalina.jar:8.0.36]
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528) [catalina.jar:8.0.36]
    	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099) [tomcat-coyote.jar:8.0.36]
    	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670) [tomcat-coyote.jar:8.0.36]
    	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) [tomcat-coyote.jar:8.0.36]
    	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476) [tomcat-coyote.jar:8.0.36]
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
    	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-util.jar:8.0.36]
    	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_131]
    Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'goodsInoutServiceImpl' available
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:687) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1213) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:275) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:522) ~[spring-context-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:496) ~[spring-context-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:627) ~[spring-context-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:169) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:318) ~[spring-context-4.3.16.RELEASE.jar:4.3.16.RELEASE]
    	... 67 common frames omitted

原因分析：

Error creating bean with name 'mgmtFactoryInoutDetailsController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'goodsInoutServiceImpl' available
    	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:321)

解决方案

在dubbo-provider.xml添加对应的声明暴露服务

<dubbo:service interface="ue.biz.service.biz.GoodsInoutService" ref="goodsInoutServiceImpl"/>

在dubbo-consumer.xml添加对应的服务订阅

<dubbo:reference id="goodsInoutServiceImpl" interface="ue.biz.service.biz.GoodsInoutService"/>

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