Hi, On Wed, Feb 29, 2012 at 12:37 AM, Allen Gilbert <[email protected]> wrote: > Hello, > > I'm trying to crack a strange, intermittent bug that's cropped up on our > production site. We're using Wicket 1.5.4, and receive the following stack > trace a couple times a day under nominal load: > > 2012-02-23 14:24:57,051 ERROR [ajp-0.0.0.0-8009-2] > [org.apache.wicket.serialize.java.JavaSerializer] error writing object > [Page class = com.company.web.pages.account.MyAccount, id = 8, render count > = 2]: null > java.util.ConcurrentModificationException > at java.util.ArrayList.writeObject(ArrayList.java:573) > at sun.reflect.GeneratedMethodAccessor252.invoke(Unknown Source) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at > java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945) > at > java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1469) > ... > at > java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330) > at > org.apache.wicket.serialize.java.JavaSerializer$CheckerObjectOutputStream.writeObjectOverride(JavaSerializer.java:250) > at > java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326) > at > org.apache.wicket.serialize.java.JavaSerializer.serialize(JavaSerializer.java:77) > at > org.apache.wicket.pageStore.DefaultPageStore.serializePage(DefaultPageStore.java:368) > at > org.apache.wicket.pageStore.DefaultPageStore.storePage(DefaultPageStore.java:146) > at > org.apache.wicket.page.PageStoreManager$PersistentRequestAdapter.storeTouchedPages(PageStoreManager.java:383) > at > org.apache.wicket.page.RequestAdapter.commitRequest(RequestAdapter.java:171) > at > org.apache.wicket.page.AbstractPageManager.commitRequest(AbstractPageManager.java:94) > at > org.apache.wicket.page.PageManagerDecorator.commitRequest(PageManagerDecorator.java:68) > at > org.apache.wicket.page.PageAccessSynchronizer$2.commitRequest(PageAccessSynchronizer.java:281) > at org.apache.wicket.Application$2.onDetach(Application.java:1598) > at > org.apache.wicket.request.cycle.RequestCycleListenerCollection$3.notify(RequestCycleListenerCollection.java:99) > at > org.apache.wicket.request.cycle.RequestCycleListenerCollection$3.notify(RequestCycleListenerCollection.java:97) > at > org.apache.wicket.util.listener.ListenerCollection$1.notify(ListenerCollection.java:119) > at > org.apache.wicket.util.listener.ListenerCollection.reversedNotify(ListenerCollection.java:143) > at > org.apache.wicket.util.listener.ListenerCollection.reversedNotifyIgnoringExceptions(ListenerCollection.java:113) > at > org.apache.wicket.request.cycle.RequestCycleListenerCollection.onDetach(RequestCycleListenerCollection.java:95) > at > org.apache.wicket.request.cycle.RequestCycle.onDetach(RequestCycle.java:600) > at > org.apache.wicket.request.cycle.RequestCycle.detach(RequestCycle.java:539) > at > org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:287) > at > org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:162) > at > org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:218) > at > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) > ... > > Looking at our logs, there doesn't seem to be anything interesting going on > around the time of these exceptions. We're not spawning any threads on our > own, and we haven't overridden any serialization-related mechanisms (or > defined custom writeObject methods), so I'm at a loss as to where I should > look for the cause of this error. Any ideas?
I'd search in Google :-) Here are some matching results: https://groups.google.com/group/memcached-session-manager/browse_thread/thread/195b954d10160348?pli=1 http://forums.terracotta.org/forums/posts/list/6500.page The problem is that another thread uses this ArrayList while it is being serialized. Now you have to find which instance of ArrayList is shared. If it is from Wicket code then it is our bug but I guess it is in your code otherwise many people would have this problem. > > Thanks! > > -Allen -- Martin Grigorov jWeekend Training, Consulting, Development http://jWeekend.com --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
