Tomcat SEVERE: Error listenerStart - Debugging.

From my travels across Google, this error is common. In Grails applications it is almost always from a bad datasource.groovy file. This error is the non descriptive string you receive when deploying your servlet (Grails, Spring, Otherwise) to tomcat (probably version 5.5 or higher). The servlet probably runs fine in development mode on your machine. How do we debug it? Read on.

Lets start by getting more useful error messages from Tomcat.
Tomcat by default uses java.util.logging, which is giving you the basic error messages along the lines of...


DATETIME org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
DATETIME org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/AppName] startup failed due to previous errors

Lets configure tomcat to use log4j, which will produce a much better call stack to debug. Taken from advice here, I'll paraphrase [read the source material for a full understanding however].

1. Stop Tomcat
2. Install Log4j on your deployment machine. (package install available for a lot of linux distros)
3. Download tomcat-juli-adapters.jar and tomcat-juli.jar from the extras section of the tomcat website (For version 7.0 that extras page is here) and place them into the $CATALINA_HOME/lib folder
4. Replace the $CATALINA_HOME/bin/tomcat-juli.jar with that same tomcat-juli.jar you just placed in lib.
5. Delete $CATALINA_BASE/conf/logging.properties to prevent the old logging system from being used
6. Start Tomcat

In my case, the error stack now looked like the following. As you can see like an idiot I had left the driverClassName to the grails 2.0 default of  org.h2.Driver instead of the com.mysql.jdbc.Driver required to connect to a mysql service. Interestingly my eclipse/tomcat development setup was forgiving me and loading the correct driver anyway - be warned!

SEVERE: Exception sending context initialized event to listener instance of class org.codehaus.groovy.grails.web.context.GrailsContextLoaderListener

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creati$

        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)

        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)

        at java.util.concurrent.FutureTask.run(FutureTask.java:166)

        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)

        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)

        at java.lang.Thread.run(Thread.java:679)

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.sp$

        ... 6 more

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Cannot resolve reference to bean 'hibernateProperties' while setting bean property 'hibernateProperties'; nested exception is $

        ... 6 more

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect];$

        ... 6 more

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while e$

        ... 6 more

Caused by: org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class 'org.h2.Driver' for connect URL '$

        ... 6 more

Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class 'org.h2.Driver' for connect URL 'jdbc:mysql://xxx.xx.xx.xx:3306/mydatabasename?autoreconnect=true&zeroDateTimeBehavior=convertToNull'

        at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1452)

        at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1371)

        at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)

        ... 6 more

Caused by: java.sql.SQLException: No suitable driver

        at java.sql.DriverManager.getDriver(DriverManager.java:279)

        at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1437)

        ... 8 more