Hibernate version: 3.2.5.ga

Full stack trace of any exception that occurs:
28/11 20:16:50 WARN AbstractBatcher [resin-tcp-connection-myserver:6001-15] Could not close a JDBC result set
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:841)
at java.util.HashMap$KeyIterator.next(HashMap.java:877)
at org.hibernate.jdbc.AbstractBatcher.closeStatements(AbstractBatcher.java:314)
at org.hibernate.jdbc.ConnectionManager.cleanup(ConnectionManager.java:382)
at org.hibernate.jdbc.ConnectionManager.close(ConnectionManager.java:324)
at org.hibernate.impl.SessionImpl.close(SessionImpl.java:298)
at org.springframework.orm.hibernate3.SessionFactoryUtils.closeSession(SessionFactoryUtils.java:774)
at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.closeSession(OpenSessionInViewFilter.java:252)
at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:183)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:70)
at com.caucho.server.cache.CacheFilterChain.doFilter(CacheFilterChain.java:188)
at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:178)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
at com.caucho.server.hmux.HmuxRequest.handleRequest(HmuxRequest.java:419)
at com.caucho.server.port.TcpConnection.run(TcpConnection.java:389)
at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:492)
at com.caucho.util.ThreadPool.run(ThreadPool.java:425)
at java.lang.Thread.run(Thread.java:595)

[repeat this a thousand times or more]

Name and version of the database you are using: MySQL 5.0.42


In case there is a ConcurrentModificationException thrown when iterating over the resultSetsToClose HashSet in AbstractBatcher.closeStatements() the exception will be caught by the catch(Throwable) clause. However, the iteration may continue infinitely because of the corrupted HashSet. This pegs one CPU and produces a large log file.

The catch(Throwable) block was added in Hibernate 3.2.3 if I saw that correctly. Apparently the reason was to catch a NPE thrown by a sybase driver here, but catching Throwable produces this side-effect.

I can submit a bug report to JIRA about this, but I wanted to post it here first in case I miss something... thanks!

This is happening to us as well. I am running version 3.2.4.sp1 against microsoft sql server using their driver.

I am unable to recreate it on demand. It is filling up the disk with log messages in short order.

I reported this in JIRA:
http://opensource.atlassian.com/project ... e/HHH-3006

Please vote for it if you want to have it addressed.

If understand correctly the Session (EntityManager) object is not thread safe. Only the factories are. To me it looks like as if that assumption has been broken. Very hard to say where the root cause of this problem is. Candidates are: the Spring framework, your application or Hibernate itself.

In your application are you passing the session object to any worker threads 'spawned' by your servlet code?