Spring Cloud踩坑指南

1 Spring Cloud搭建

参考 Spring Cloud 微服务技术栈：搭建高可用 Eureka Server、服务注册与发现

2 常见问题

2.1 修改hosts配置文件

这修改的是主机的hosts文件，而不是在项目中新增配置文件。

2.2 版本问题

Spring Cloud - Spring Boot 的版本是严格对应，如果pom中二者版本不对应，那么会导致项目启动失败，问题出在bean的生成这边。

2.3 Mac机器上 restTemplate报错

题主第一次用mac搭建Spring cloud项目，但是在服务调用方调用服务提供方的时候报错，报错提示如下

2020-11-18 15:59:06.306  INFO 2193 --- [erListUpdater-0] c.netflix.config.ChainedDynamicProperty  : Flipping property: producer-service.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2020-11-18 15:59:08.173 ERROR 2193 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.client.ResourceAccessException: I/O error on GET request for "http://producer-service/hello/producer": Unexpected end of file from server; nested exception is java.net.SocketException: Unexpected end of file from server] with root causejava.net.SocketException: Unexpected end of file from serverat sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:851) ~[na:1.8.0_261]at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:678) ~[na:1.8.0_261]at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:848) ~[na:1.8.0_261]at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:678) ~[na:1.8.0_261]at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1593) ~[na:1.8.0_261]at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498) ~[na:1.8.0_261]at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480) ~[na:1.8.0_261]at org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:82) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.http.client.InterceptingClientHttpRequest$InterceptingRequestExecution.execute(InterceptingClientHttpRequest.java:108) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.cloud.client.loadbalancer.LoadBalancerRequestFactory.lambda$createRequest$0(LoadBalancerRequestFactory.java:59) ~[spring-cloud-commons-2.0.2.RELEASE.jar:2.0.2.RELEASE]at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:112) ~[spring-cloud-netflix-ribbon-2.0.2.RELEASE.jar:2.0.2.RELEASE]at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:94) ~[spring-cloud-netflix-ribbon-2.0.2.RELEASE.jar:2.0.2.RELEASE]at org.springframework.cloud.client.loadbalancer.LoadBalancerInterceptor.intercept(LoadBalancerInterceptor.java:55) ~[spring-cloud-commons-2.0.2.RELEASE.jar:2.0.2.RELEASE]at org.springframework.http.client.InterceptingClientHttpRequest$InterceptingRequestExecution.execute(InterceptingClientHttpRequest.java:92) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.http.client.InterceptingClientHttpRequest.executeInternal(InterceptingClientHttpRequest.java:76) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:687) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:644) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:323) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at com.example.springcloudeurekaconsumerclient1.ConsumerController.helloConsumer(ConsumerController.java:21) ~[classes/:na]at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_261]at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_261]at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_261]at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_261]at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:891) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498) [tomcat-embed-core-8.5.34.jar:8.5.34]at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.34.jar:8.5.34]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_261]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_261]at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.34.jar:8.5.34]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_261]

问题出在这个请求server时候出现的SocketException上，实在找不到报错原因，换了一台Win机器重新搭建系统，发现不报错，配置相同。但是有问题不能忽略，因此找了很多资料，文末会列出几个相关的博客。觉得应该是服务方提供的IP的原因，服务调用方能拉到服务提供方的服务列表，但是无法去访问这些服务。这些服务注册都成功了，也能本地访问。但是通过服务调用方经过负载均衡调用就找不到对应的ip和端口。最后将原本的服务提供方的配置文件从

# 配置服务名称
spring.application.name=producer-service
# 配置服务注册地址
eureka.client.service-url.defaultZone=http://localhost:1111/eureka/

更改为

# 配置服务名称
spring.application.name=producer-service
# 配置服务注册地址
eureka.client.service-url.defaultZone=http://localhost:1111/eureka/
eureka.instance.prefer-ip-address=true

新增的一个配置项的含义是优先用服务提供方的IP进行注册。这样服务调用方就能找到这个服务提供方提供的服务了。

2.4 父子项目打成可执行jar包问题

我的项目架构如下所示

如今我要实现的整个系统架构由以下几个部分组成：

服务注册中心（eureka-server）：注册中心用于发现全部的服务，系统内部的所有服务（同一个服务可能有多个镜像资源）都要在注册中心进行注册，这样是便于系统分布式扩张的。

服务提供方（producer-client）：全部服务的实际执行者。每种服务有多个资源为用户提供服务，该部分包含业务逻辑的处理。

服务调用方（consumer-client）：服务调用方是服务的唯一入口，全部的请求都需要在这边进行分发，采用ribbon的restTemplate进行负载均衡。

如今我只需要配好一个多节点的服务注册中心，然后让全部要上线的服务都在注册中心注册，就可以非常方便的进行分布式扩张。

在这边我将producer-client进行打包，形成jar包之后，只要服务资源不够了，我在另外的机器上java -jar运行这个jar，就可以非常方便的进行扩张。打包的时候，需要在父工程项目的pom文件中增加一个配置项：

<packaging>pom</packaging>

并且用maven进行打包，打包完父项目工程之后，才能进行子项目工程的打包。然后每次启动服务就运行如下命令即可：

java -jar spring-cloud-eureka-producer-client-1-0.0.1-SNAPSHOT.jar --server.port=8083

参考：

https://blog.csdn.net/hjkuanggong/article/details/106851094

https://blog.csdn.net/wangmx1993328/article/details/88232648

https://blog.csdn.net/yihanxiaoxiao1/article/details/78489466