Tomxin7
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业务介绍
最近用Spring Boot开发了一个翻译的小项目，但是服务器上还跑着其他项目，包括一个同样用Spring Boot开发的微信后端服务，本次业务需要在阿里云的Linux使用同一个Tomcat容器部署多个项目。
部署环境：JDK8、Tomcat8、Centos7
遇到的问题
我多个项目一直都是部署在同一个Tomcat下，共用80端口，之前使用的MVC或者Servlet项目都没有问题，但是今天把新的Spring Boot项目部署上去之后，Tomcat直接抛出异常，并且该项目无法访问，其他项目正常。
org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [HikariDataSource (null)] with key 'dataSource'; nested exception is javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:625) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.jmx.export.MBeanExporter.lambda$registerBeans$2(MBeanExporter.java:551) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at java.util.HashMap.forEach(HashMap.java:1288) ~[na:1.8.0_131]
at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:551) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:434) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:762) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:398) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:330) ~[spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:157) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:137) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:172) [spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5292) [catalina.jar:8.0.36]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147) [catalina.jar:8.0.36]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725) [catalina.jar:8.0.36]
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701) [catalina.jar:8.0.36]
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717) [catalina.jar:8.0.36]
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092) [catalina.jar:8.0.36]
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1834) [catalina.jar:8.0.36]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_131]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_131]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_131]
Caused by: javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437) ~[na:1.8.0_131]
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898) ~[na:1.8.0_131]
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966) ~[na:1.8.0_131]
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900) ~[na:1.8.0_131]
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324) ~[na:1.8.0_131]
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522) ~[na:1.8.0_131]
at org.springframework.jmx.support.MBeanRegistrationSupport.doRegister(MBeanRegistrationSupport.java:137) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:671) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:615) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
... 27 common frames omitted
2018-08-06 23:07:37.857 INFO 13141 --- [.cn-startStop-1] ConfigServletWebServerApplicationContext : Closing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@67ae851c: startup date [Mon Aug 06 23:07:32 CST 2018]; root of context hierarchy
2018-08-06 23:07:37.858 INFO 13141 --- [.cn-startStop-1] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown
06-Aug-2018 23:07:37.860 SEVERE [api.fanyi.tomxin.cn-startStop-1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[api.fanyi.tomxin.cn].StandardContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:153)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1834)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [HikariDataSource (null)] with key 'dataSource'; nested exception is javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:625)
at org.springframework.jmx.export.MBeanExporter.lambda$registerBeans$2(MBeanExporter.java:551)
at java.util.HashMap.forEach(HashMap.java:1288)
at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:551)
at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:434)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:762)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:398)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:330)
at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:157)
at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:137)
at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91)
at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:172)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5292)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
... 10 more
Caused by: javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
at org.springframework.jmx.support.MBeanRegistrationSupport.doRegister(MBeanRegistrationSupport.java:137)
at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:671)
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:615)
... 27 more
06-Aug-2018 23:07:37.861 SEVERE [api.fanyi.tomxin.cn-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Error deploying web application directory /soft/tomcat/apache-tomcat-8.0.36/webapps/fanyi/api/ROOT
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[api.fanyi.tomxin.cn].StandardContext[]]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:729)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1834)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
解决过程
这里截取部分截图和报错信息，在网上查了很久，很多解决方法是需要修改项目的web.xml，可是在Spring Boot项目中，并没有web.xml文件，期间一直以为是自己项目代码问题，但是线下部署都完全正常，后来怀疑是不是Tomcat同时部署的项目有上限，但是没有查询到相关例子，直到后来先暂停了项目中的另一个Spring Boot项目之后，发现新项目居然申请的跑起来了，尝试的查找了一下多Spring Boot项目部署的问题，才发现了这个坑。
解决方案
Spring Boot的spring.jmx资源管理是默认打开的，而两个项目同时使用会冲突，网上有两种解决办法，我用的是第一种，第二种大家自测：
修改配置文件：application.properties(yml)
办法1：在项目配置中加入：spring.jmx.enabled=false
办法2：
在application中各自配置
spring.jmx.default-domain=project1
spring.jmx.default-domain=project2
以保证domain是两个不一样的