Re: Auto-reconnect

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Sun Mar 30 2003 - 03:26:20 EST

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    Oh, and should I mention that these changes had a very nice side effect
    - now all actual connections are "lazy" for all databases. So unless
    you perform a query or some other operation, Cayenne will not try to
    connect. I wanted to implement this long time ago (all those hours
    spent to prevent modeler from starting connections when the DataNode is
    created :-)).

    [Note that logging still needs to be fixed - it incorrectly shows a
    connection event when the DataNode is loaded, not when the actual
    connection is opened much later]

    Andrus

    On Sunday, March 30, 2003, at 03:08 AM, Andrus Adamchik wrote:

    > Some time back I argued that automated reconnect is close to
    > impossible to implement in Cayenne connection package:
    >
    > http://objectstyle.org/cayenne/lists/cayenne-user/2003/01/0023.html
    >
    > This is only partially true. Just figured how to restart failed
    > PooledConnectionImpl on Oracle (some simple refactoring, I will be
    > checking it in soon).
    >
    > Unfortunately on other databases, calls like
    > "connection.prepareStatement" are local, and Exception is not thrown
    > immediately (even if the database is down), but only when a statement
    > is executed. So make it robust, theoretically we will must wrap not
    > only the Connection (with a ConnectionWrapper), but also all the
    > objects returned from it (Statements, ResultSets, etc.) I think this
    > is a bit over the board and I will not do it now. Maybe instead we
    > will eventually simply create an expiration parameter that will allow
    > to retire "old" connections. I think this is how many pools actually
    > work...
    >
    > Andrus
    >
    >



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