Hey there,

I am having a problem where the database connection dies after a certain period of inactive time and I receive the below error message. Any thoughts?

Using: Tomcat 5.5.17, JRE 1.6, MySQL 5.0.24



Mar 2, 2007 7:22:43 AM org.hibernate.transaction.JDBCTransaction commit
SEVERE: JDBC commit failed
com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Communications link failure during commit(). Transaction resolution unknown.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:888)
at com.mysql.jdbc.Connection.commit(Connection.java:2285)
at org.hibernate.transaction.JDBCTransaction.commitAndResetAutoCommit(JDBCTransaction.java:139)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:115)
at common.servlet.HibernateFilter.doFilter(HibernateFilter.java:54)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.valves.FastCommonAccessLogValve.invoke(FastCommonAccessLogValve.java:495)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:833)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:639)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1285)
at java.lang.Thread.run(Unknown Source)
Mar 2, 2007 7:22:43 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet jsp threw exception
org.hibernate.TransactionException: JDBC commit failed
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:130)
at common.servlet.HibernateFilter.doFilter(HibernateFilter.java:54)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.valves.FastCommonAccessLogValve.invoke(FastCommonAccessLogValve.java:495)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:833)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:639)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1285)
at java.lang.Thread.run(Unknown Source)
Caused by: com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Communications link failure during commit(). Transaction resolution unknown.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:888)
at com.mysql.jdbc.Connection.commit(Connection.java:2285)
at org.hibernate.transaction.JDBCTransaction.commitAndResetAutoCommit(JDBCTransaction.java:139)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:115)
... 14 more


Here is my connection URL within Tomcat's server.xml:

<Resource name="jdbc/myDataSource" auth="Container" type="javax.sql.DataSource" username="me" password="me" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/thedb?autoReconnect=true" maxActive="0" maxIdle="1"/>

Thanks a bunch!

Dont use hibernate connection pool. I use c3p0. That would hopefully solve your problem

Thanks Somu!! Got any examples of how to implement c3p0?

Thanks so much, I really appreicate it!!

Use this in your hibernate configuration file
<!-- C3P0 Connection Pool Settings -->
<property name="c3p0.min_size">4</property>
<property name="c3p0.max_size">20</property>
<property name="c3p0.timeout">1800</property>
<property name="c3p0.max_statements">100</property>
<property name="c3p0.idle_test_period">540</property>
<property name="c3p0.acquire_increment">2</property>
<property name="c3p0.validate">false</property>

Ensure c3p0.jar is present in your classpath.

Hope that helps.