Re: Cayenne in j2ee - message beans

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Tue Mar 18 2008 - 04:08:39 EDT

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    Essentially this results in creation of a few HashMaps... Not very
    expensive by itself. My note on performance was mostly related to the
    fact that DataContext level caching will not have a chance to play
    significant role in a short-lived context.

    Andrus

    On Mar 18, 2008, at 2:35 AM, Gary Jarrel wrote:

    > Thank you for the quick reply.
    >
    > I know I should probably do some of my own profiling, but is the
    > process of
    > creating a new datacontext expensive computation wise?
    >
    > Thank you!
    >
    > Gary
    >
    > On Tue, Mar 18, 2008 at 4:55 AM, Andrus Adamchik <andru..bjectstyle.org
    > >
    > wrote:
    >
    >> The simplest thing to do is to limit the scope of the thread
    >> DataContext to the 'onMessage' method. I.e. create a new context on
    >> entry, bind it to the current thread, and unbind it in the "finally"
    >> block... The performance impact is of course that you need to refetch
    >> everything related to your processing on every call, which may or may
    >> not be a problem.
    >>
    >> Andrus
    >>
    >>
    >> On Mar 17, 2008, at 4:18 PM, Gary Jarrel wrote:
    >>
    >>> Hi All!
    >>>
    >>> One of the requirements of the current project I'm working on is to
    >>> use a
    >>> j2ee environment and message driven beans in an application server
    >>> such as
    >>> glassfish.
    >>>
    >>> There is also a requirement to use a custom DAO library which relies
    >>> on a
    >>> thread bound data context.
    >>>
    >>> Basically the message bean receives a text message via JMS an
    >>> prior to
    >>> processing it, it must be stored in the database, then, once
    >>> processed the
    >>> results are also stored in a database.
    >>>
    >>> I've always tried to avoid EJBs however, in this case, my question
    >>> is: has
    >>> anyone got any "best practice" advice on how a data context should
    >>> be
    >>> created and bound to the thread in a message bean environment.
    >>>
    >>> The message beans are quite simple, in that they only receive the
    >>> messages,
    >>> an then call upon spring POJOs to do the processing of the messages.
    >>>
    >>> Thank you in advance.
    >>>
    >>> garyj
    >>
    >>



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