ConcurrentModificationException when serializing session in
archerzz Nov 13, 2007 10:54 PMHi all, recently I found that "ConcurrentModificationException" happened a few times in the server log. I know that JBoss 4.0.3sp1 has a bug:http://jira.jboss.com/jira/browse/JBAS-3137 on that. It's said that this problem is fixed. But now I met this again. Please see below. Also I found that before and after this exception happened, there were warning message "[org.jboss.resource.connectionmanager.CachedConnectionManager] Closing a connection for you. Please close them yourself:" around it.
My configuration: JBoss 4.2.1GA + JDK 1.5.0_13. Any suggestion is appreciated. Thanks!
2007-11-13 08:22:57,418 ERROR [org.jboss.web.tomcat.service.session.JBossCacheService] externalizeSession(): exception occurred externalizing session SessionBasedClusteredSession[id: QyohhhjQAARi2HkAreBYvg**.server1 lastAccessedTime: 1194942177369 version: 765 lastOutdated: 0] java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:841) at java.util.HashMap$EntryIterator.next(HashMap.java:883) at java.util.HashMap$EntryIterator.next(HashMap.java:881) at java.util.HashMap.writeObject(HashMap.java:1037) at sun.reflect.GeneratedMethodAccessor183.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:917) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1339) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1290) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1079) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1375) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1347) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1290) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1079) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:302) at java.util.concurrent.ConcurrentHashMap.writeObject(ConcurrentHashMap.java:1380) at sun.reflect.GeneratedMethodAccessor191.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:917) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1339) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1290) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1079) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:302) at org.jboss.web.tomcat.service.session.SessionBasedClusteredSession.writeExternal(SessionBasedClusteredSession.java:175) at org.jboss.web.tomcat.service.session.JBossCacheService.externalizeSession(JBossCacheService.java:1027) at org.jboss.web.tomcat.service.session.JBossCacheService.putSession(JBossCacheService.java:316) at org.jboss.web.tomcat.service.session.JBossCacheClusteredSession.processSessionRepl(JBossCacheClusteredSession.java:121) at org.jboss.web.tomcat.service.session.JBossCacheManager.processSessionRepl(JBossCacheManager.java:1097) at org.jboss.web.tomcat.service.session.JBossCacheManager.storeSession(JBossCacheManager.java:652) at org.jboss.web.tomcat.service.session.InstantSnapshotManager.snapshot(InstantSnapshotManager.java:49) at org.jboss.web.tomcat.service.session.ClusteredSessionValve.invoke(ClusteredSessionValve.java:98) at org.jboss.web.tomcat.service.session.JvmRouteValve.invoke(JvmRouteValve.java:84) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104) at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241) at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:437) at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:381) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:595) 2007-11-13 08:22:57,421 INFO [org.jboss.resource.connectionmanager.CachedConnectionManager] Closing a connection for you. Please close them yourself: org.jboss.resource.adapter.jdbc.WrappedConnection@701eae java.lang.Throwable: STACKTRACE at org.jboss.resource.connectionmanager.CachedConnectionManager.registerConnection(CachedConnectionManager.java:290) at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:417) at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:842) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:88) at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:112) at com.nsite.processserver.ConnectionManager.getConnection(ConnectionManager.java:174) at org.apache.jsp.c.rulesdesigner.DecisionTableBuilder_jsp._jspService(DecisionTableBuilder_jsp.java:133) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:387) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.nsite.filter.URLProcessorFilter.doFilter(URLProcessorFilter.java:39) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.nsite.filter.GZIPFilter.doFilter(GZIPFilter.java:23) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.nsite.config.RequestContextManager.doFilter(RequestContextManager.java:31) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:174) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:77) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179) at org.jboss.web.tomcat.service.session.ClusteredSessionValve.invoke(ClusteredSessionValve.java:87) at org.jboss.web.tomcat.service.session.JvmRouteValve.invoke(JvmRouteValve.java:84) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104) at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241) at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:437) at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:381) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:595)