Java 无法为事务打开JPA EntityManager-通信链路故障（Spring boot/JPA/hibernate/connection pool）

我们有一个

REST

请求进入到我们的应用程序中，该应用程序来回处理数据库中的各种任务。请求完成后，无法回发到数据库进行最终更新

我们可以看到，从开始到结束处理请求大约需要9.5个小时

问题

• 我们想知道为什么会发生这个问题，解决这个问题的最佳方法是什么
• 我们考虑过修改

  连接池

  ，但我们认为可能需要移动到不同的

  连接池

  ，或者可能需要更改

  MySQL

  的配置方式

如果您有任何可能有帮助的细节，我们将不胜感激

多谢各位

配置

# DataSource settings: set here your own configurations for the database
  # connection.
  datasource:
    url: jdbc:mysql://localhost/test
    username: test
    password: test
    driverClassName: com.mysql.jdbc.Driver

    # Keep the connection alive if idle for a long time (needed in production)
    tomcat:
      testWhileIdle: true
      timeBetweenEvictionRunsMillis: 60000
      validationQuery: SELECT 1

  jpa:
    properties:
      hibernate:
        # The SQL dialect makes Hibernate generate better SQL for the chosen database
        dialect: org.hibernate.dialect.MySQL5Dialect
        # Use hibernates new generator mappings, this is used for the appium port using a TABLE generator
        id.new_generator_mappings: true

错误

ERROR c.m.m.a.config.RestErrorHandler -  Error occurred: POST:/api/testRuns/61376/execute
org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

堆栈跟踪

     The last packet successfully received from the server was 33,089,829 milliseconds ago.  The last packet sent successfully to the server was 8 milliseconds ago.
      at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:431)
      at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373)
      at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:447)
      at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:277)
      at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
      at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655)
      at com.miw.mcb.adbservice.service.TestRunService$$EnhancerBySpringCGLIB$$e48faff9.completeTestRun(<generated>)
      at com.miw.mcb.adbservice.controller.HomeController.runTestRun(HomeController.java:145)
      at com.miw.mcb.adbservice.controller.HomeController.runTestRun(HomeController.java:60)
      at com.miw.mcb.adbservice.controller.HomeController$$FastClassBySpringCGLIB$$dc33ec77.invoke(<generated>)
      at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
      at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651)
      at com.miw.mcb.adbservice.controller.HomeController$$EnhancerBySpringCGLIB$$591244dd.runTestRun(<generated>)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:220)
      at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)
      at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)
      at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
      at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
      at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
      at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
      at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
      at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
      at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
      at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:105)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:317)
      at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
      at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:215)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:121)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
      at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214)
      at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177)
      at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
      at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:89)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:107)
      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
      at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
      at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
      at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
      at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410)
      at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
      at java.lang.Thread.run(Thread.java:745)
    Caused by: javax.persistence.PersistenceException: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

    The last packet successfully received from the server was 33,089,829 milliseconds ago.  The last packet sent successfully to the server was 8 milliseconds ago.
      at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692)
      at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602)
      at org.hibernate.jpa.spi.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:1700)
      at org.hibernate.jpa.internal.TransactionImpl.begin(TransactionImpl.java:48)
      at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:189)
      at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:380)
      ... 112 common frames omitted
    Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

    The last packet successfully received from the server was 33,089,829 milliseconds ago.  The last packet sent successfully to the server was 8 milliseconds ago.
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
      at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
      at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
      at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
      at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:988)
      at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3552)
      at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3452)
      at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3893)
      at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2526)
      at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2673)
      at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545)
      at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4842)
      at sun.reflect.GeneratedMethodAccessor115.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:126)
      at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
      at org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:81)
      at com.sun.proxy.$Proxy7.setAutoCommit(Unknown Source)
      at org.hibernate.resource.jdbc.internal.AbstractLogicalConnectionImplementor.begin(AbstractLogicalConnectionImplementor.java:67)
      at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:238)
      at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.begin(JdbcResourceLocalTransactionCoordinatorImpl.java:214)
      at org.hibernate.engine.transaction.internal.TransactionImpl.begin(TransactionImpl.java:52)
      at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1512)
      at org.hibernate.jpa.internal.TransactionImpl.begin(TransactionImpl.java:45)
      ... 114 common frames omitted
    Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
      at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3004)
      at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3462)
      ... 133 common frames omitted

从服务器成功接收的最后一个数据包是33089829毫秒前。成功发送到服务器的最后一个数据包是8毫秒前。
位于org.springframework.orm.jpa.JpaTransactionManager.doBegin（JpaTransactionManager.java:431）
位于org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction（AbstractPlatformTransactionManager.java:373）
在org.springframework.transaction.interceptor.TransactionSpectSupport.CreateTransactionIfEssential（TransactionSpectSupport.java:447）上
位于org.springframework.transaction.interceptor.TransactionSpectSupport.invokeWithinTransaction（TransactionSpectSupport.java:277）
位于org.springframework.transaction.interceptor.TransactionInterceptor.invoke（TransactionInterceptor.java:96）
在org.springframework.aop.framework.ReflectiveMethodInvocation.procedue（ReflectiveMethodInvocation.java:179）上
位于org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept（CglibAopProxy.java:655）
在com.miw.mcb.adbservice.service.TestRunService$$EnhancerBySpringCGLIB$$e48faff9.completeTestRun（）上
在com.miw.mcb.adbservice.controller.HomeController.runTestRun（HomeController.java:145）上
在com.miw.mcb.adbservice.controller.HomeController.runTestRun（HomeController.java:60）上
在com.miw.mcb.adbservice.controller.HomeController$$FastClassBySpringCGLIB$$dc33ec77.invoke（）上
位于org.springframework.cglib.proxy.MethodProxy.invoke（MethodProxy.java:204）
位于org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept（CglibAopProxy.java:651）
在com.miw.mcb.adbservice.controller.HomeController$$EnhancerBySpringCGLIB$$591244dd.runTestRun（）上
在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处
位于sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）
在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）中
位于java.lang.reflect.Method.invoke（Method.java:498）
位于org.springframework.web.method.support.InvocableHandlerMethod.doInvoke（InvocableHandlerMethod.java:220）
位于org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest（InvocableHandlerMethod.java:134）
位于org.springframework.web.servlet.mvc.method.annotation.ServletinVaccableHandlerMethod.invokeAndHandle（ServletinVaccableHandlerMethod.java:116）
位于org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod（RequestMappingHandlerAdapter.java:827）
位于org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal（RequestMappingHandlerAdapter.java:738）
位于org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle（AbstractHandlerMethodAdapter.java:85）
位于org.springframework.web.servlet.DispatcherServlet.doDispatch（DispatcherServlet.java:963）
位于org.springframework.web.servlet.DispatcherServlet.doService（DispatcherServlet.java:897）
位于org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:970）
位于org.springframework.web.servlet.FrameworkServlet.doPost（FrameworkServlet.java:872）
位于javax.servlet.http.HttpServlet.service（HttpServlet.java:707）
位于org.springframework.web.servlet.FrameworkServlet.service（FrameworkServlet.java:846）
位于javax.servlet.http.HttpServlet.service（HttpServlet.java:790）
位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:230）
位于org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:165）
位于org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）
位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:192）
位于org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:165）
位于org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal（ApplicationContextHeaderFilter.java:55）
位于org.springframework.web.filter.OncePerRequestFilter.doFilter（OncePerRequestFilter.java:107）
位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:192）
位于org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:165）
位于org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal（WebRequestTraceFilter.java:105）
位于org.springframework.web.filter.OncePerRequestFilter.doFilter（OncePerRequestFilter.java:107）
位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:192）
位于org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:165）
位于org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter（FilterChainProxy.java:317）
位于org.springframework.security.web.access.intercept.filtersecuritynt
<bean id="c3p0DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close">
    <property name="driverClass" value="com.mysql.jdbc.Driver" />
    <property name="jdbcUrl" value="#{systemProperties.dbhost}" />
    <property name="user" value="#{systemProperties.dbuser}" />
    <property name="password" value="#{systemProperties.dbpass}" />
    <property name="maxPoolSize" value="25" />
    <property name="minPoolSize" value="10" />
    <property name="maxStatements" value="100" />
    <property name="testConnectionOnCheckout" value="true" />
</bean>