Investigate and fix HTTP 500 error

[Willem Elbers]

HTTP Status 500 - unexpected error when rollbacking

type Exception report

message unexpected error when rollbacking

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.persistence.PersistenceException: unexpected error when rollbacking
	org.hibernate.ejb.TransactionImpl.rollback(TransactionImpl.java:110)
	eu.clarin.cmdi.virtualcollectionregistry.DataStore.closeEntityManager(DataStore.java:78)
	eu.clarin.cmdi.virtualcollectionregistry.rest.PersistenceFilter.doFilter(PersistenceFilter.java:38)
	de.mpg.aai.shhaa.AuthFilter.doFilter(AuthFilter.java:84)
root cause

org.hibernate.exception.GenericJDBCException: Cannot release connection
	org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
	org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
	org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
	org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
	org.hibernate.jdbc.ConnectionManager.closeConnection(ConnectionManager.java:478)
	org.hibernate.jdbc.ConnectionManager.aggressiveRelease(ConnectionManager.java:429)
	org.hibernate.jdbc.ConnectionManager.afterTransaction(ConnectionManager.java:316)
	org.hibernate.jdbc.JDBCContext.afterTransactionCompletion(JDBCContext.java:269)
	org.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:204)
	org.hibernate.ejb.TransactionImpl.rollback(TransactionImpl.java:107)
	eu.clarin.cmdi.virtualcollectionregistry.DataStore.closeEntityManager(DataStore.java:78)
	eu.clarin.cmdi.virtualcollectionregistry.rest.PersistenceFilter.doFilter(PersistenceFilter.java:38)
	de.mpg.aai.shhaa.AuthFilter.doFilter(AuthFilter.java:84)
root cause

java.sql.SQLException: Already closed.
	org.apache.tomcat.dbcp.dbcp.PoolableConnection.close(PoolableConnection.java:114)
	org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.close(PoolingDataSource.java:191)
	org.hibernate.connection.DatasourceConnectionProvider.closeConnection(DatasourceConnectionProvider.java:97)
	org.hibernate.jdbc.ConnectionManager.closeConnection(ConnectionManager.java:474)
	org.hibernate.jdbc.ConnectionManager.aggressiveRelease(ConnectionManager.java:429)
	org.hibernate.jdbc.ConnectionManager.afterTransaction(ConnectionManager.java:316)
	org.hibernate.jdbc.JDBCContext.afterTransactionCompletion(JDBCContext.java:269)
	org.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:204)
	org.hibernate.ejb.TransactionImpl.rollback(TransactionImpl.java:107)
	eu.clarin.cmdi.virtualcollectionregistry.DataStore.closeEntityManager(DataStore.java:78)
	eu.clarin.cmdi.virtualcollectionregistry.rest.PersistenceFilter.doFilter(PersistenceFilter.java:38)
	de.mpg.aai.shhaa.AuthFilter.doFilter(AuthFilter.java:84)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.54 logs.

[Twan Goosen]

What is the exact context, i.e. what can I do to reproduce it?
I have encountered the "Already closed" exception before and it seems to be related to how Wicket and Hibernate (do not) work together. My proposal would be to make the front end use the REST service instead, which IMO should simplify the application architecture as well. But if needed, we can investigate this issue some more :)

[Willem Elbers]

The context is currently unkown. This happens now and then on the production instance upon accessing ​http://clarin.ids-mannheim.de/vcr/app/public, but it is not easy to reproduce.

[Willem Elbers]

This doesn't happen anymore