Re: DataObject expiring?

From: Bryan Lewis (jbryanlewi..mail.com)
Date: Wed Jan 06 2010 - 07:28:40 EST

  • Next message: Marek Šab: "Re: DataObject expiring?"

    Marek, would you like the honor of opening the Jira? Your stack trace will
    be more useful than my story.

    On Wed, Jan 6, 2010 at 5:25 AM, Andrus Adamchik <andru..bjectstyle.org>wrote:

    > Would you mind opening a Jira with these details and include the JVM
    > version and maybe the CPU type on your server?
    >
    > Weak references in Cayenne 3.0 are at the ObjectStore level and should not
    > affect relationships, if Java works correctly. I.e. related objects are
    > store via hard references.
    >
    > Andrus
    >
    >
    >
    >
    > On Jan 6, 2010, at 4:45 AM, Bryan Lewis wrote:
    >
    > This rings a bit of a bell with me. We made our first big release with
    >> Cayenne 3.0 a couple of weeks ago (it went well, thank you) and saw a
    >> similar-sounding problem. It happened only intermittently and only on our
    >> production server. We could never reproduce it on our test server, let
    >> alone in a debugger.
    >>
    >> We had an object stored in the session. Our editor-page initialization
    >> code
    >> got the object and then the value of its to-one relationship. This
    >> related
    >> object would occasionally be null.
    >>
    >> StoryDetail object from session ---to-one---> Story (occasionally
    >> null)
    >>
    >> We couldn't pin down how to reproduce it. (The user it kept happening too
    >> works very remotely.) My guess was some kind of garbage collection. The
    >> user would enter a lot of text for several minutes and then save/refresh
    >> the
    >> page and get the NPE. The other hint was that the same code had never had
    >> a
    >> problem in two years with Cayenne 2. On the other hand, I was unable to
    >> reproduce it by adding explicit garbage collection calls so my guess could
    >> be off base.
    >>
    >> I worked around it by refetching the list of StoryDetails, with a prefetch
    >> on Story, so that the desired Story object would always be freshly
    >> fetched.
    >>
    >>
    >>
    >> On Tue, Jan 5, 2010 at 3:31 PM, Andrus Adamchik <andru..bjectstyle.org
    >> >wrote:
    >>
    >> On the surface looks like some (de)serialization issue. Although that
    >>> doesn't make much sense, as RelationshipFault.relationshipOwner is not
    >>> transient and can't be reset to null easily. The best bet is to run this
    >>> in
    >>> debugger to get a better picture of what's going on with your objects.
    >>>
    >>> Andrus
    >>>
    >>>
    >>> On Jan 5, 2010, at 10:13 PM, Marek Šabo wrote:
    >>>
    >>> Hi all,
    >>>>
    >>>> is there any way that a dataobject could expire? I mean i'm storing
    >>>> user's
    >>>> settings dataobject in session and after a while, say max 5 min. when I
    >>>> try
    >>>> to submit a form that binds this data as foreign key I got a nullpointer
    >>>> exception from setting up that relationship. I think it does't expire in
    >>>> session because I'm still logged in and only way is to logout and login
    >>>> back
    >>>> to have the setting reloaded from database. Appending end of stacktrace:
    >>>>
    >>>> at
    >>>>
    >>>> org.apache.cayenne.util.RelationshipFault.isTransientParent(RelationshipFault.java:70)
    >>>> at
    >>>>
    >>>> org.apache.cayenne.util.PersistentObjectList.isFault(PersistentObjectList.java:75)
    >>>> at
    >>>>
    >>>> org.apache.cayenne.util.PersistentObjectList.add(PersistentObjectList.java:125)
    >>>> at
    >>>>
    >>>> org.apache.cayenne.CayenneDataObject.addToManyTarget(CayenneDataObject.java:282)
    >>>> at
    >>>>
    >>>> org.apache.cayenne.CayenneDataObject.setReverseRelationship(CayenneDataObject.java:364)
    >>>> at
    >>>>
    >>>> org.apache.cayenne.CayenneDataObject.setToOneTarget(CayenneDataObject.java:315)
    >>>>
    >>>> Thanks for any ideas,
    >>>>
    >>>> Regards
    >>>>
    >>>> --
    >>>> Marek Šabo
    >>>>
    >>>>
    >>>
    >>>
    >



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