Re: Commits not visible across contexts in ROP

From: Tarik Cherkovi (cherta..mail.com)
Date: Fri Feb 13 2009 - 00:43:50 EST

  • Next message: Aristedes Maniatis: "Re: Commits not visible across contexts in ROP"

    Oh, I didn't realize that ROP clients have their own independent views of
    the data and that commits are not visible to others. (They seem to refresh
    sometimes when I run a fresh query, but other times, they are not.
     Collections don't refresh at all...) I thought there were a number of
    projects using ROP in production environment and I would imagine this is a
    common requirement. How are people getting around it if at all?Building
    event propagation on the server would be great, but as you say, it's non
    trivial. So in the meantime, I would need to find another solution (other
    than rewriting my entire swing gui in gwt...) How would I refresh all
    caches programmatically? I ll try that and see what performance looks
    like...

    Tarik

    On Fri, Feb 13, 2009 at 12:28 AM, Aristedes Maniatis <ar..sh.com.au> wrote:

    >
    > On 13/02/2009, at 3:30 PM, Tarik Cherkovi wrote:
    >
    > Hi,I just had a strange behavior from ROP and maybe missing something
    >> basic.
    >> I have multiple clients connecting to the same server, and when one of
    >> them
    >> performs a commit, the changes are not visible to the other client(s). Is
    >> there a way to make all remote contexts?
    >>
    >
    > You'll need to implement that behaviour yourself. Obviously the simplistic
    > approach is to refresh all caches and queries on the remote client before
    > you use data where freshness is important.
    >
    > The problem isn't a trivial one. If you have a bunch of clients on
    > different subnets, they can't necessarily pass events directly to each other
    > using JMS or something similar. So the server needs to be responsible for
    > holding a list of update events which are then passed out to clients upon
    > request. You could implement something with SnapshotEvents [1] which are
    > passed either directly between clients (if they have direct access to each
    > other) or via the server as an intermediary. Personally I didn't get much
    > further than identifying a couple of libraries such as Apache Mina and
    > Apache ActiveMQ which might be useful in such an implementation.
    >
    > But I am keen on implementing something for our own applications, if only
    > we had more time....
    >
    > Ari
    >
    >
    > [1] http://cayenne.apache.org/doc/object-caching.html
    >
    >
    >
    >
    > -------------------------->
    > ish
    > http://www.ish.com.au
    > Level 1, 30 Wilson Street Newtown 2042 Australia
    > phone +61 2 9550 5001 fax +61 2 9550 4001
    > GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A
    >
    >
    >



    This archive was generated by hypermail 2.0.0 : Fri Feb 13 2009 - 00:44:28 EST