I am working on a Spring hibernate project which is on Heroku and uses ClearDB. When my page is idle for some time (hardly a minute) and then I send some request to the server I get the error as follows:
HTTP ERROR 500
Problem accessing /authenticate.action. Reason:
Communications link failure
Last packet sent to the server was 16 ms ago.; nested exception is org.hibernate.exception.JDBCConnectionException: Communications link failure
Last packet sent to the server was 16 ms ago.
Caused by:
org.springframework.dao.DataAccessResourceFailureException: Communications link failure
Last packet sent to the server was 16 ms ago.; nested exception is org.hibernate.exception.JDBCConnectionException: Communications link failure
Last packet sent to the server was 16 ms ago.
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:631)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:104)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:403)
at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:58)
at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:163)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at sun.proxy.$Proxy33.authenticate(Unknown Source)
Caused by: org.hibernate.exception.JDBCConnectionException: Communications link failure
Last packet sent to the server was 16 ms ago.
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:131)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:129)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at sun.proxy.$Proxy75.executeQuery(Unknown Source)
I tried looking up on the net for answers and I made some configuration settings as follows:
Heres my datasource configuration:
<beans:bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<beans:property name="url" value="#{ 'jdbc:mysql://' + @dbUrl.getHost() + @dbUrl.getPath() + '?reconnect=true'}"/>
<beans:property name="username" value="#{ @dbUrl.getUserInfo().split(':')[0] }"/>
<beans:property name="password" value="#{ @dbUrl.getUserInfo().split(':')[1] }"/>
<beans:property name="minEvictableIdleTimeMillis" value="1800000"/>
I still get the error every time I leave the page idle for a minute or so. I dont get this error if my requests to the server are non stop.
My understanding is that, this is something related to idle connections in connection pool. I never got this error when I had the database running on my local machine. Its only on Heroku that I get this error. Has anybody else got a similar problem?
Thanks, Kiran
