前言

最近，测试环境遇到了一个问题。经过一番百度加谷歌，终于解决了这个问题。写下这篇博客是为了记录下解决过程，以便以后查看。也希望可以帮助更多的人。

环境

  • java版本：8
  • 框架：spring cloude Finchley.RELEASE
  • 数据库连接池：c3p0

问题描述

将程序部署到测试环境后，程序运行正常，但第二天（期间没有任何人访问）首次访问会报错 Could not open JPA EntityManager for transaction ，后面访问就都正常了。下面是详细的报错：

  1. 2018-09-29 11:53:30.683 ERROR 5897 --- [io-18086-exec-7] o.h.engine.jdbc.spi.SqlExceptionHelper   : Already closed.
  2. 2018-09-29 11:53:30.699 ERROR 5897 --- [io-18086-exec-7] 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.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is org.hibernate.TransactionException: JDBC begin transaction failed: ] with root cause
  3.  
  4. java.net.SocketException: 断开的管道 (Write failed)
  5.     at java.net.SocketOutputStream.socketWrite0(Native Method) ~[na:1.8.0_171]
  6.     at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111) ~[na:1.8.0_171]
  7.     at java.net.SocketOutputStream.write(SocketOutputStream.java:155) ~[na:1.8.0_171]
  8.     at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) ~[na:1.8.0_171]
  9.     at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) ~[na:1.8.0_171]
  10.     at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3731) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
  11.     at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2512) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
  12.     at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
  13.     at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2482) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
  14.     at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4796) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
  15.     at org.apache.commons.dbcp.DelegatingConnection.setAutoCommit(DelegatingConnection.java:371) ~[commons-dbcp-1.4.jar!/:1.4]
  16.     at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.setAutoCommit(PoolingDataSource.java:328) ~[commons-dbcp-1.4.jar!/:1.4]
  17.     at org.hibernate.resource.jdbc.internal.AbstractLogicalConnectionImplementor.begin(AbstractLogicalConnectionImplementor.java:67) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
  18.     at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:263) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
  19.     at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.begin(JdbcResourceLocalTransactionCoordinatorImpl.java:214) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
  20.     at org.hibernate.engine.transaction.internal.TransactionImpl.begin(TransactionImpl.java:56) ~[hibernate-core-5.2.17.Final.jar!/:5.2.17.Final]
  21.     at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:164) ~[spring-orm-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  22.     at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:400) ~[spring-orm-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  23.     at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:378) ~[spring-tx-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  24.     at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:474) ~[spring-tx-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  25.     at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:289) ~[spring-tx-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  26.     at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) ~[spring-tx-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  27.     at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  28.     at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  29.     at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  30.     at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135) ~[spring-data-jpa-2.0.7.RELEASE.jar!/:2.0.7.RELEASE]
  31.     at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  32.     at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  33.     at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  34.     at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61) ~[spring-data-commons-2.0.7.RELEASE.jar!/:2.0.7.RELEASE]
  35.     at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  36.     at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  37.     at com.sun.proxy.$Proxy99.save(Unknown Source) ~[na:na]
  38.     at org.springframework.data.repository.support.CrudRepositoryInvoker.invokeSave(CrudRepositoryInvoker.java:101) ~[spring-data-commons-2.0.7.RELEASE.jar!/:2.0.7.RELEASE]
  39.     at org.springframework.data.rest.core.support.UnwrappingRepositoryInvokerFactory$UnwrappingRepositoryInvoker.invokeSave(UnwrappingRepositoryInvokerFactory.java:179) ~[spring-data-rest-core-3.0.7.RELEASE.jar!/:3.0.7.RELEASE]
  40.     at org.springframework.data.rest.webmvc.RepositoryEntityController.createAndReturn(RepositoryEntityController.java:476) ~[spring-data-rest-webmvc-3.0.7.RELEASE.jar!/:3.0.7.RELEASE]
  41.     at org.springframework.data.rest.webmvc.RepositoryEntityController.postCollectionResource(RepositoryEntityController.java:272) ~[spring-data-rest-webmvc-3.0.7.RELEASE.jar!/:3.0.7.RELEASE]
  42.     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
  43.     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
  44.     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
  45.     at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
  46.     at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  47.     at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  48.     at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  49.     at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  50.     at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  51.     at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  52.     at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  53.     at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  54.     at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  55.     at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  56.     at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  57.     at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  58.     at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  59.     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  60.     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  61.     at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.31.jar!/:8.5.31]
  62.     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  63.     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  64.     at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  65.     at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  66.     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  67.     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  68.     at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  69.     at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  70.     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  71.     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  72.     at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  73.     at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  74.     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  75.     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  76.     at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  77.     at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.6.RELEASE.jar!/:5.0.6.RELEASE]
  78.     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  79.     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  80.     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.31.jar!/:8.5.31]
  81.     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  82.     at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  83.     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  84.     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  85.     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  86.     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  87.     at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  88.     at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  89.     at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  90.     at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  91.     at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  92.     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_171]
  93.     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_171]
  94.     at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.31.jar!/:8.5.31]
  95.     at java.lang.Thread.run(Thread.java:748) [na:1.8.0_171]

错误分析

通过上面的错误信息百度找到了原因，原来数据库的链接默认的超时时间是8个小时，如果在8个小时里没有访问，那么这个连接就会被回收。数据库通过 wait_timeout 和 interactive_timeout 去设置这个超时时间，他们有如下的区别（下面的文字摘自这里）：

  • interactive_timeout 针对交互式连接， wait_timeout 针对非交互式连接。所谓的交互式连接，即在 mysql_real_connect() 函数中使用了 CLIENT_INTERACTIVE 选项。说得直白一点，通过mysql客户端连接数据库是交互式连接，通过jdbc连接数据库是非交互式连接。

  • 在连接启动的时候，根据连接的类型，来确认会话变量 wait_timeout 的值是继承于全局变量 wait_timeout ，还是 interactive_timeout 。

解决方案

通过上面的错误分析，我们可以想出以下的解决方案：

  1. 将 wait_timeout 和 interactive_timeout 设置的很大，使得期间不会出现无人访问的情况（不推荐，秉承能在程序里解决的，绝不动环境）
  2. 设置一个定时任务，要过期的时候访问下数据库（不推荐）
  3. 对于非连接池玩家，需要在 jdbcUrl 上设置 &autoReconnect=true
  4. 对于连接池玩家，设置连接池属性，使得可以自动重连

由于我们使用的是连接池，所以我们使用方案4来解决问题（注意不同的连接池属性设置是不一样的，本文是针对c3p0连接池的解决方案），下面是我们解决问题的过程（解决方案参考这里，里面有其他连接池的配置，但我试着设置过，不起作用，无奈只能改成c3p0连接池，如果哪位大虾知道其他连接池怎么配置，还请赐教）：

  • pom文件 添加 c3p0 的依赖
  1. <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
  2. <dependency>
  3.     <groupId>com.mchange</groupId>
  4.     <artifactId>c3p0</artifactId>
  5.     <version>0.9.5.2</version>
  6. </dependency>
  • 配置文件里添加以下配置

application.yml:

  1. spring:
  2.   datasource:
  3.     jdbcUrl: jdbc:mysql://localhost:3306/database_name?useSSL=false&characterEncoding=utf8&autoReconnect=true&failOverReadOnly=false
  4.     user: xxx
  5.     password: xxx
  6.     type: com.mchange.v2.c3p0.ComboPooledDataSource
  7.     driverClass: com.mysql.jdbc.Driver
  8.     maxPoolSize: 200
  9.     minPoolSize: 10
  10.     initialPoolSize: 10
  11.     acquireIncrement: 5
  12.     idleConnectionTestPeriod: 28800
  13.     maxIdleTime: 28800
  • 配置 DataSource 使用 c3p0 连接池

DataSourceConfiguration.java:

  1. import org.springframework.beans.factory.annotation.Qualifier;
  2. import org.springframework.boot.context.properties.ConfigurationProperties;
  3. import org.springframework.boot.jdbc.DataSourceBuilder;
  4. import org.springframework.context.annotation.Bean;
  5. import org.springframework.context.annotation.Configuration;
  6. import org.springframework.context.annotation.Primary;
  7.  
  8. import javax.sql.DataSource;
  9.  
  10. @Configuration
  11. public class DataSourceConfiguration {
  12.     @Bean(name = "dataSource")
  13.     @Qualifier(value = "dataSource")
  14.     @Primary
  15.     @ConfigurationProperties(prefix = "spring.datasource")
  16.     public DataSource dataSource(){
  17.         DataSource dataSource= DataSourceBuilder.create()
  18.                 .type(com.mchange.v2.c3p0.ComboPooledDataSource.class).build();
  19.         return dataSource;
  20.     }
  21. }

至此，该问题就解决了，如果中间有什么说错的，还请各位大虾指正。

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