[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-3006) ConcurrentModificationException in AbstractBatcher results in infinite loop

[Remi Gerbaud (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/HHH-3006?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_29762 ] 

Remi Gerbaud commented on HHH-3006:
-----------------------------------

We got the same problem with 3.2.6ga, tomcat 5.5 and MySQL 5.0.51-3.
But this problem comes once per day... We must restart tomcat to stop the increase of the log size...

We got this problem since we put 3.2.6 instead of 3.2.2, and we don't find any fix, so if someone have an idea, we can try it.

> ConcurrentModificationException in AbstractBatcher results in infinite loop
> ---------------------------------------------------------------------------
>
>                 Key: HHH-3006
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-3006
>             Project: Hibernate3
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 3.2.5
>         Environment: Hibernate 3.2.5.ga
> MySQL 5.0.42
>            Reporter: Stefan Hauk
>            Assignee: Steve Ebersole
>            Priority: Minor
>         Attachments: batcherinfinitelooptest.zip, batcherinfinitelooptest.zip
>
>
> Here is a piece of code from org.hibernate.jdbc.AbstractBatcher's closeStatements() method:
> Iterator iter = resultSetsToClose.iterator();
> while ( iter.hasNext() ) {
> 	try {
> 		logCloseResults();
> 		( (ResultSet) iter.next() ).close();
> 	}
> 	catch (SQLException e) {
> 		// no big deal
> 		log.warn("Could not close a JDBC result set", e);
> 	}
> 	catch (Throwable e) {
> 		// sybase driver (jConnect) throwing NPE here in certain cases
> 		log.warn("Could not close a JDBC result set", e);
> 	}
> }
> resultSetsToClose.clear();
> In case there is a ConcurrentModificationException thrown when iterating over the resultSetsToClose HashSet 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 logs the following stack trace over and over again:
> 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)
> 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 catches more than that and produces this side-effect.
> Now I do realize that the ConcurrentModificationException might be caused by not using Hibernate in a correct way, but I haven't determined the cause for it yet. However, I do think that Hibernate should fail more gracefully than it currently does.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira