Re: Session Replication

From: Mike Kienenberger (mkienen..mail.com)
Date: Wed May 05 2010 - 17:10:16 EDT

  • Next message: Mike Kienenberger: "Re: Session Replication"

    Hmm. Unfortunately, I can't remember if my issue with that project
    was that the DataContext wasn't being serialized or that it was and I
    didn't want it to. And this was 1.2, so the behavior may have changed
    since then.

    But in either case, it seems pretty trivial.

    In the case of it being serialized, it already does what you want

    In the case of it not being serialized, you'd create a new DataContext
    and dump in all of the serialized objects you had from the original
    DataContext.

    I don't think there's any state that needs to be saved for a
    DataContext other than the DataObjects it contains. Maybe you'd also
    need to save the initial fetched object snapshots if you were working
    with optimistic locking.

    All I can say for sure is that I did a JSF project where we saved the
    uncommitted DataObjects out as client-side data (serialized into the
    generated html), then read them back in on the next request. The
    data would survive application restarts, so it should be equivalent to
    moving it to another session or another server.

    I tried glancing through what project source code I had laying around,
    but I couldn't find the code that dealt with the serialization -- too
    many project modules to look through.

    On Wed, May 5, 2010 at 4:57 PM, Michael Gentry <mgentr..asslight.net> wrote:
    > My experience with Tapestry (4 & 5) serializing a DataObject to the
    > HTML (which it does by default when you have a loop in a form) is that
    > the deserializing of the DataObject (on the subsequent
    > request/response) gives you a DataObject that is disassociated from
    > the DataContext (not good).  Perhaps if the DataContext went along for
    > the ride all would be well ...
    >
    > Thanks,
    >
    > mrg
    >
    >
    > On Wed, May 5, 2010 at 4:53 PM, Mike Kienenberger <mkienen..mail.com> wrote:
    >> No direct experience, but I know you can serialize DataObjects and I'm
    >> 99% certain you can serialize DataContexts.   I think I did this in
    >> one project in the past to preserve state between requests rather than
    >> saving state in the sessions.
    >>
    >> On Wed, May 5, 2010 at 4:37 PM, Michael Gentry <mgentr..asslight.net> wrote:
    >>> Someone on another project here asked me if Cayenne works with session
    >>> replication (with 1+ user DataContext objects in the HttpSession)
    >>> between application servers (such as JBoss).  They have a project
    >>> where they are running N instances of JBoss and they replicate/sync
    >>> the session data across the JBoss instances.  They are curious if the
    >>> DataContext + DataObjects will replicate correctly.  I've never
    >>> attempted to do so and am not sure.  Does anyone have experience with
    >>> this?
    >>>
    >>> Thanks!
    >>>
    >>> mrg
    >>>
    >>
    >



    This archive was generated by hypermail 2.0.0 : Wed May 05 2010 - 17:11:14 EDT